floating crane- this is a crane installed permanently on a special vessel, both self-propelled and non-self-propelled, and designed to perform lifting and handling operations.
2.1.1. General information
Unlike other types of cranes, floating cranes are provided with living quarters for the crew (permanent crew), repair and rigging workshops, canteens, additional ship equipment, deck mechanisms, and their own power plants, allowing the crane to operate autonomously away from the coast. The mechanisms of floating cranes are, as a rule, diesel-electric driven. Power supply from the shore is also possible. Propellers or vane propellers are used as propellers. The latter do not require a steering device and can move the crane forward, backward, sideways (lag) or deploy on the spot.
Depending on the waterways, floating cranes are under the jurisdiction of the Russian Maritime Register of Shipping or the Russian River Register.
In accordance with the requirements of the Maritime Register, floating cranes must be equipped with all the devices provided for ships, i.e. must have fenders (wooden beams protruding along the outer part of the ship's freeboard continuously or in parts, protecting the side plating from hitting other ships and structures), capstans (ship mechanisms in the form of vertical gates for lifting and releasing anchors, lifting weights, pulling moorings etc.), bollards (paired bollards with a common plate on the deck of the ship, designed to fasten cables to them), anchors and anchor winches, as well as light and sound signaling, radio communications, sump pumps and life-saving equipment. During operation, the floating crane must have a supply of fresh water, food, fuel and lubricants according to the standards for the time of autonomous navigation. The main requirements for floating crane pontoons are structural strength, buoyancy and stability.
In the case of transportation by inland waterways, the overall height of the crane in the stowed state must comply with GOST 5534 and be assigned taking into account the scaffold dimensions and the possibility of passing under overhead power lines.
By purpose, cranes can be classified as follows:
Transfer cranes(general purpose), intended for mass handling operations (their description is presented in the works). According to GOST 5534, the lifting capacity of transshipment floating cranes is 5, 16 and 25 tons, the maximum reach is 30 ... 36 m, the minimum is 9 ... 11 m, the hook lifting height above the water level is 18.5 ... into the hold of the vessel) - not less than 11 ... 20 m (depending on the carrying capacity), lifting speed 1.17 ... 1.0 m / s (70 ... 45 m / min), departure change rate 0.75 ... 1.0 m / s (45 ... 60 m / min), speed 0.02 ... 0.03 s -1 (1.2 ... 1.75 rpm) . These are cranes such as, for example, Ganz, manufactured in Hungary (Fig. 2.1.), Domestic cranes (Fig. 2.2).
Special purpose cranes(large load capacity) - for reloading heavyweights, construction, installation, shipbuilding and rescue operations.
floating cranes for installation work, are used in the construction of hydraulic structures, for work at shipbuilding and ship repair plants.
The crane of the German company "Demag" with a lifting capacity of 350 tons was used in the reconstruction of Leningrad bridges, during the installation
80-ton portal cranes, when transferring portal cranes from one port area to another, etc.
Crane plant PTO them. S. M. Kirov with a carrying capacity of 250 tons was made for the installation of oil rigs in the Caspian Sea.
Cranes "Chernomorets" with a lifting capacity of 100 tons and "Bogatyr" with a lifting capacity of 300 tons (Fig. 2.3) were awarded the State Prize of the USSR.
Rice. 2.2. Transfer floating cranes with a lifting capacity of 5 tons ( A) and 16 tons ( b): 1 - grab at the longest reach; 2 - trunk; 3 - an arrow in a stowed position; 4 - emphasis; 5 - an arrow in a working way; 6 - pontoon; 7 - grab at the smallest reach; 8 - cabin; 9 - turntable; 10 - column; 11 - balancing device, combined with the mechanism for changing the departure; 12 - counterweight
Rice. 2.3. Floating crane "Bogatyr" with a lifting capacity of 300 tons (Sevastopol plant named after S. Ordzhonikidze): 1 - pontoon; 2 - an arrow in a stowed position; 3 - auxiliary lifting suspension; 4 - suspension of the main lift; 5 - arrow
The Vityaz crane (Fig. 2.4) with a lifting capacity of 1600 tons is used when working with heavy loads, for example, when installing bridge structures across a river on supports mounted on the shore. In addition to the main hoist, this crane has an auxiliary hoist with a lifting capacity of 200 tons. Departure of the main hoist 12 m, auxiliary 28.5 m. There are floating cranes and higher carrying capacity.
Special cranes for reloading heavyweights in ports, installation and construction works in the construction of ships, ship repair and construction of hydroelectric power stations, rescue operations, have full-revolving topsides. Lifting capacity - from 60 (Astrakhan crane) to 500 tons, for example: Chernomorets - 100 tons, Sevastopol - 140 tons (Fig. 2.5), Bogatyr - 300 tons, Bogatyr-M - 500 tons . On fig. 2.6 shows the cranes "Bogatyr" with various modifications of the booms and the corresponding graphs of load capacity, variable in reach.
Specialized cranes for ship lifting and rescue operations and installation of large-sized heavy structures, as a rule, are fixed.
Rice. 2.5. Floating crane "Sevastopolets" with a lifting capacity of 140 tons (Sevastopol plant named after S. Ordzhonikidze): 1 - pontoon; 2 - an arrow in a stowed position; 3 - arrow in a working way
|
Rice. 2.6. Floating cranes: A- "Bogatyr"; b- "Bogatyr-3" with an additional arrow; V- "Bogatyr-6" with an extended additional boom; Q– permissible load capacity at the outreach R; H- lifting height
Examples of such cranes are: "Volgar" - 1400 tons; "Vityaz" - 1600 tons (Fig. 2.4), lifting a load weighing 1600 tons is carried out using a winch of three deck hoists, "Magnus" (Magnus, Germany) with a lifting capacity of 200 to 1600 tons (Fig. 2.7), "Balder" (Balder , Holland) with a carrying capacity from 2000 to 3000 tons (Fig. 2.8).
Oilfield. Crane vessels for the supply of offshore oil fields and the construction of offshore oil and gas facilities usually have rotary topsides, a significant reach and lifting height, and are capable of servicing stationary drilling platforms. Such cranes include, for example, "Yakub Kazimov" - with a lifting capacity of 25 tons (Fig. 2.9), "Kerr-ogly" - with a lifting capacity of 250 tons. In connection with the development of the continental shelf, there is a tendency to increase the parameters of cranes of this group (lifting capacity - up to 2000 ... 2500 tons and more).
Rice. 2.7. Floating crane "Magnus" with a lifting capacity of 800 tons (HDW, Germany): 1 - pontoon; 2 - an arrow in a stowed position; 3 – deck winch; 4 – jib tilt winch; 5 - brace; 6 - arrow; 7 - goose; 8 - suspension of the main lift; 9 - auxiliary lifting suspension
Rice. 2.8. Floating crane "Balder" with a lifting capacity of 3000 tons ("Gusto", Holland - ( A) and a schedule for changing the permissible load capacity Q from departure R (b)):
1 - pontoon; 2 - turntable; 3 - arrow; I ... IV - hook suspensions
Rice. 2.9. Crane vessel "Yakub Kazimov": 1 - pontoon; 2 - an arrow in a stowed position; 3 - equalizing chain hoist; 4 - cabin; 5 - frame of the turning part
Depending on seaworthiness, cranes can be classified as follows:
1) port (to perform reloading operations in ports and harbors, closed water bodies and coastal sea (coastal) and river areas, at shipbuilding and ship repair yards);
2) seaworthy (for work on the high seas with the possibility of long independent transitions).
The domestic crane industry is characterized by the desire to create universal cranes, and for foreign - highly specialized cranes.
2.1.2. Floating cranes
Floating cranes consist of a superstructure (the crane itself) and a pontoon (a special or crane vessel).
Superstructure of floating crane, crane ship, etc.- a lifting structure installed on an open deck, designed to carry a lifting device and cargo.
pontoons, like the hulls of ships, they consist of transverse (frames and deck beams) and longitudinal (keel and kilsons) elements sheathed with sheet steel.
Frame - curved transverse beam of the ship's hull set, providing strength and stability of the sides and bottom.
Beam- a transverse beam connecting the right and left branches of the frame. A deck is laid on the beams.
Keel- a longitudinal connection established in the diametrical plane of the vessel near the bottom, extending along its entire length. The keel of large and medium-sized vessels (internal vertical) is a sheet installed in the diametrical plane between the double bottom decking and the bottom plating. To reduce pitching, side keels are installed normally to the outer skin of the vessel. The length of the side keel is up to 2/3 of the length of the vessel.
kilson- longitudinal connection on ships without a double bottom, installed along the bottom and connecting the lower parts of the frames for their joint work.
The shape of the pontoons is a parallelepiped with rounded corners or have ship contours. Pontoons with rectangular corners have a flat bottom and a cut in the aft (or bow) part (Fig. 2.10). Sometimes the crane is mounted on two pontoons (catamaran crane). In these cases, each pontoon has a more or less pronounced keel and a shape similar to the shape of the hulls of ordinary ships. The pontoons of floating cranes are sometimes made unsinkable, i.e. supplied with longitudinal and transverse bulkheads. To increase the stability of a floating crane, i.e. the ability to return from a deflected position to an equilibrium position after removing the load, it is necessary to lower its center of gravity if possible. To do this, high superstructures should be avoided, and living quarters for the crane team and warehouses should be placed inside the pontoon. Only the wheelhouse (ship control cabin), galley (ship kitchen) and dining room are taken out on deck. Inside the pontoon, along its sides, there are tanks (tanks) for diesel fuel and fresh water.
Floating cranes can be self-propelled and non-self-propelled. If the crane is intended to serve several ports or to travel long distances, then it must be self-propelled. In this case, pontoons with ship contours are used. Seaworthy cranes have pontoons with ship contours, a number of heavy cranes use catamaran pontoons (Ker-ogly with a lifting capacity of 250 tons; a crane from Vartsila, Finland, with a lifting capacity of 1600 tons, etc.).
According to the design of the upper structure floating cranes can be classified into non-slewing, full-slewing and combined.
fixed(mast, gantry, with swinging (tilting) arrows). Mast cranes (with fixed masts) have simple design and low cost. The horizontal movement of cargo is carried out when moving the pontoon, so the performance of such cranes is very small.
Rice. 2.10. Floating crane pontoon scheme
For work with heavyweights, floating cranes with tilting booms are more suitable. With a variable reach, their performance is greater than that of mast ones. These cranes have a simple structure, low cost and large lifting capacity. The crane boom consists of two posts converging to the top at an acute angle, and is hinged in the bow of the pontoon. The boom is lifted by a rigid rod (hydraulic cylinder, gear rack or screw device) or using a chain hoist mechanism (for example, on the Vityaz crane). The boom in the transport position is fixed on a special support (Fig. 2.3). To perform this operation, a boom and auxiliary winch is used.
The floating gantry crane is a conventional gantry crane mounted on a pontoon. The bridge of the crane is located along the longitudinal axis of the pontoon, and its only console protrudes beyond the contours of the pontoon for a distance, sometimes called the outer reach. The external reach is usually 7…10 m. The lifting capacity of floating gantry cranes reaches 500 tons. However, due to the high metal consumption, floating gantry cranes are not produced in our country.
Full revolving(universal) cranes come with a turntable or column. Currently, slewing cranes with a tilting boom are widely used. They are the most productive. Their arrows not only tilt, but also rotate around a vertical axis. The lifting capacity of slewing cranes varies widely and can reach hundreds of tons.
Full-revolving cranes include the Bogatyr crane with a lifting capacity of 300 tons and an external outreach of 10.4 m with a lifting height of the main hook (hook) above sea level of 40 m, as well as an offshore transport and assembly vessel Ilya Muromets. The latter has a lifting capacity of 2 × 300 tons at an external outreach of 31 m. The height of the crane vessel with a raised boom is 110 m. These cranes are capable of crossing the sea with a storm of 6 ... 7 points and a wind of 9 points. Autonomy of navigation 20 days. The speed of the crane "Bogatyr" is 6 knots, and the speed of the crane vessel "Ilya Muromets" is 9 knots. Both ships are equipped with a set of mechanisms and devices that provide high level mechanization of the main and auxiliary processes. In the transport position, the booms of both described vessels are placed on special supports and fixed.
Combined. These include, for example, floating gantry cranes, on the bridge of which a rotary crane moves.
The prevailing type of boom arrangement of floating cranes is a straight boom with an equalizing chain hoist; less often, articulated boom devices are used, but their use is associated with difficulties in laying in a stowed position.
To prevent tilting of the straight booms of marine cranes during waves, under the action of inertia and wind forces, as well as when the load breaks and is dropped, the booms are equipped with safety devices in the form of limit stops or special balancing systems. At Magnus cranes, the boom with the load is held by a rigid strut.
With the development of boom designs, a transition was made from lattice and non-braced booms to solid-walled (box-shaped, less often tubular) booms in a beam or cable-stayed design. On cranes of recent years of production, sheet box-shaped arrows are more often used. However, lattice booms of some foreign cranes of very large lifting capacity are known (Balder crane, see Fig. 2.8). When upgrading cranes, the base booms are often extended with additional cable-stayed booms (see Fig. 2.6), which makes it possible to significantly increase the maximum reach and lifting height and at the same time ensure wide unification with the base model.
The main types of slewing bearings for floating cranes are slewing and non-slewing columns, multi-roller slewing circle, slewing ring in the form of a double-row roller bearing. There is a trend towards the use of slewing circles in the form of roller bearings on cranes with a lifting capacity of up to 500 tons. On heavier cranes, multi-roller slewing circles are still used, work is underway to create segmented roller bearings for such cranes.
The lifting mechanisms used on floating cranes are grab winches with independent drums and differential switches. According to GOST 5534, a reduced landing speed of the grab on the load is provided, which is 20 ... 30% of the main speed. It is possible to replace the grab with a hook suspension.
Turning mechanisms (one or two) often have helical-bevel gearboxes with multi-plate clutches of limiting torque and an open gear or pinion gear.
Departure change mechanism - sectoral with installation of sectors on the counterweight lever or hydraulic with a hydraulic cylinder connected to the platform and a rod connected to the counterweight lever. Cranes with a screw mechanism for changing the departure are known. The designs of the mechanisms for changing the reach are presented in section 1 "Portal cranes".
Floating handling clamshell cranes in river and seaports exploited very intensively. For lifting mechanisms, the PV values reach 75 ... 80%, turning mechanisms - 75%, departure change mechanisms - 50%, the number of inclusions per hour - 600.
2.1.3. Calculation features
Geometry of the pontoon. When designing and calculating, the pontoon is considered in three mutually perpendicular planes (see Fig. 2.10). The main plane is the horizontal plane tangent to the bottom of the pontoon. One of the vertical planes, the so-called diametral plane, runs along the pontoon and divides it into equal parts. The line of intersection of the main and diametrical planes is taken as the axis X. Another vertical plane is drawn through the middle of the length of the pontoon and is called the plane of the midship frame, or midsection. The line of intersection of the main and midsection planes is taken as the axis Y, and the line of intersection of the midsection and diametral planes - behind the axis Z.
The plane parallel to the plane of the midsection and passing through the axis of rotation of the rotary crane is called medial. The lines of intersection of the surface of the pontoon hull with planes parallel to the midship plane are called frames (this is also the name of the transverse elements of the vessel that form the frame of its hull). The lines of intersection of the surface of the pontoon hull with planes parallel to the main plane are called waterlines. The same name has a trace of the surface of the water on the body of the pontoon.
Since the pontoon, located on the water, can be tilted, the resulting waterline is called the current one. The plane of the current waterline, not parallel to the planes of the other waterlines, divides the pontoon into two parts: surface and underwater. The waterline corresponding to the position on the water of a crane without a load, balanced in such a way that its main plane is parallel to the surface of the water, is called the main waterline.
The inclination of the vessel to the bow or stern is called the trim, and the inclination of the vessel to the starboard or port side is called the roll. Corner ψ (see Fig. 2.10) between the current and main waterlines in the diametral plane is called the trim angle, and the angle θ between the same lines in the midship plane - the angle of roll. When trimmed to the nose and when rolled towards the boom, the angles ψ And θ are considered positive.
Length L the pontoon is usually measured along the main waterline, the estimated width B pontoon - at the widest point of the pontoon along the waterline, and the estimated height H sides - from the main plane to the side line of the deck (see Fig. 2.10). The distance from the main plane to the current waterline is called draft T pontoon, which has different meanings at the bow of the pontoon T H and at the stern T K. Value difference T H – T K called a trim. Difference between height and draft H-T called height f freeboard. If the shape of the pontoon is not a parallelepiped, i.e. has smooth contours, then for the calculations they make up the so-called theoretical drawing that determines the external shape of the hull (several sections along the frames). With rectangular pontoons, there is no need to draw up such a drawing.
Volume V underwater part of the pontoon is called volumetric displacement. The center of gravity of this volume is called the center of magnitude and is denoted by CV. Mass of water in volume V called mass displacement D.
Stability of floating cranes. Stability - the ability of a ship to return to a position of equilibrium after the cessation of the forces that cause it to tilt.
The features of calculating the stability of floating cranes are largely reduced to taking into account the influence of roll and trim. A crane without a load must be trimmed to the stern, and with a load - to the bow. If the boom is located in the medial plane without a load, the crane should roll towards the counterweight, and with the load - towards the load. The change in departure due to roll or trim can be several meters. For the estimated departure take the departure, which has a crane with a horizontal position of the pontoon.
For a crane with a load, the rotary part of the crane with a counterweight creates a moment that partially balances the load moment and is called a balancing moment (see Fig. 2.10): M Y \u003d G K y K , Where G K- weight of the superstructure; y K- distance from the axis of rotation of the crane to the center of gravity of the superstructure (including counterweights).
For cranes with movable counterweights, the balancing moment is determined as the sum of the moments from the weights of the superstructure and counterweights.
Load moment M G = GR,Where G- weight of cargo with hook suspension; R- arrow flight. The ratio of the balancing moment to the load moment is called the balancing factor φ = M U / M G.
To determine the heeling and trim moments, consider Fig. 2.11, which shows the pontoon and boom in plan. The weight of the rotary part of the crane with a load G K applied at a distance e off axis O 1 boom rotation. Action of weight G K on the shoulder e can be replaced by a vertical force G K at the point O 1 and moment G K e in the plane of the arrow. Pontoon weight with ballast G0 attached at the point O2. In addition, the vertical moment from the wind load acts on the crane, which has components relative to the corresponding axes M IN And M BY. Then the heeling moment is determined from the dependence of the form M K = M X = G K e cos φ + M BX, and the trimming moment M D \u003d M Y \u003d G K e sin φ + M to Y.
To determine the restoring moment, consider Fig. 2.12, which shows a section of the pontoon along the midship plane in positions before and after the heeling moment is applied. The center of gravity of a crane with a pontoon is indicated DH. A crane at rest is subjected to vertical forces having a resultant force N, and the buoyant force D = Vρg, Where V- displaced volume; ρ - density of water; g- acceleration of gravity. According to the law of Archimedes, D=N.
In a state of balance of power N And D act along one vertical line passing through the center of gravity and the center of magnitude and is called the axis of navigation. In this case, the roll angle may be of some importance. θ (see fig. 2.10).
Rice. 2.11. Scheme for determining the heeling and trim moments
Rice. 2.12. Pontoon position scheme up to ( A) and after ( b) heeling moment applications
Assume that a static heeling moment is applied to the crane M K, caused, for example, by the weight of the load G at the end of the crane boom. In this case, the center of magnitude shifts. Change of forces D And G compared to the equilibrium state can be neglected, since the weight of the load is significantly less than the weight of the crane. Then strength D in the inclined position of the crane will be applied at the point CV(Fig. 2.12, b). In this case, there will be a restoring moment of forces D And N=D on the shoulder l θ equal to the heeling moment M K, i.e. , where is the transverse metacentric height, i.e. distance from the metacenter to the center of gravity.
The metacenter is the point F intersection of the axis of navigation with the line of action of the force D, and the metacentric radius is the distance from the metacenter F to the center of magnitude.
When trimmed at an angle ψ
the restoring moment is equal to the trimming moment M D, i.e. 
, where is the longitudinal metacentric height; a- the distance between the centers of gravity and magnitude. The products of and are called the coefficients of static stability.
Let's define the metacentric radii and . From the theory of the ship, the following is known:
1) at small angles of heel θ and trim ψ metacenter position F unchanged, and the center of magnitude moves along the arc of a circle described around the metacenter;
2) metacentric radius R=J/V, Where J- the moment of inertia of the area bounded by the waterline, relative to the corresponding axis around which the crane is tilted.
For a crane at rest, the area bounded by the waterline is BL.
For a rectangular pontoon (excluding contours and bevels), the moments of inertia about the main axes J X \u003d L B 3 / 12; J Y = B L 3 / 12, and the displaced volume of water V = B L T. In this case, the metacentric radii ; 
.
Thus, the roll and trim angles, depending on the heeling and trim moments, are determined from the expressions
; 
.
|
Rice. 2.13. Floating crane stability diagrams: A– static M VK(q); b - dynamic A B(q)
For slewing boom slewing cranes, these angles are variable both in reach and in angle of rotation.
The restoring moments during roll and trim are determined by formulas of the form:
; (2.1)
At roll angles greater than 15 °, formula (2.1) is not applicable, and the restoring moment M VK depending on the angle θ changes according to the static stability diagram (Fig. 2.13). With a gradual increase in the heeling moment to a value equal to the maximum value of the restoring moment M VK max on the diagram, the angle of heel reaches θ M , and the crane will be unstable, as any accidental inclination in the direction of the roll will cause it to tip over. Application of heeling moments M θ ³ M VK max is invalid. Dot TO(chart sunset) characterizes the limiting angle of roll θ P , above which M VK< 0 and the crane overturns. The static stability diagram is included in the mandatory documentation of the crane; its construction according to the drawing of the pontoon or according to approximate formulas is given in the work.
With a sudden (or for a time less than a half-period of natural oscillations) application of a dynamic moment to a non-tilted pontoon M D(see fig. 2.13, A), which remains constant in the future, in the initial period of the roll M D > M VK and the ship will roll with acceleration, accumulating kinetic energy. Reaching the angle of static roll q(dot IN), the ship will heel further up to the dynamic heel angle q D when stock kinetic energy will be spent on overcoming the work of the restoring moment and resistance forces (point WITH, corresponding to the equality of areas OAB And CBE). At q D £ 10…15 O(Fig. 2.13, A) it could be considered q D = 2q(taking into account water resistance q D= 2 xq, Where x- attenuation factor ( x" 0.7); in the presence of an initial bank angle ± q0 dynamic bank angle q D = ± q0+ 2q. Overturning dynamic moment M D.OPR and tilt angle q E.ODA determined by finding the line AE, which cuts off equal areas on the static stability diagram OAB And WME(Fig. 2.13, b).
The dynamic stability diagram (see Fig. 2.13) is a graph of the dependence of the work of the restoring moment A B= D from the angle of roll ( l q- shoulder of the restoring moment during roll (see Fig. 2.12); it is an integral curve with respect to the static stability diagram; magnitude d B = A B / D= called the shoulder of dynamic stability. Heeling moment work A K = M D q D = D d K, Where d K = A K / D D = M D q D / D– specific work of the heeling moment. Schedule A K (q D) there is a straight line OF, passing through points O And F with coordinates (1 rad, M D); Dot R intersections (see Fig. 2.13, A) or touch (see Fig. 2.13, b) diagrams of dynamic stability with a straight line OF determines the dynamic bank angle q D (A) or rollover angle with dynamic roll q E.ODA (b).
Dynamic roll (or trim) occurs when the load is jerked up or when the load breaks. On fig. 2.14 shows the position of the water mirror relative to the pontoon for an unloaded crane (equilibrium position 1 at bank angle q0) and loaded with a static roll (position 2 at bank angle q). For normal operation of the crane, it is desirable to have the equality of the absolute values of the roll angles for a loaded and empty crane. When the load breaks, the crane will oscillate about the equilibrium position 1 with amplitude Δ q(see Fig. 2.14), reaching the position 3 at dynamic bank angle q DIN = q 0+ Δ q. The values of the latter are more accurate if water resistance is taken into account, according to the formula
q DIN= q0+ (0.5 – 0.7) ∆ q.
Rice. 2.14. Scheme of a pontoon to determine the dynamic roll
Determination of the overturning moment and the angle of dynamic roll in working condition when the load is broken according to the dynamic stability diagram, as well as checking the stability of the crane during the transition, haul, in non-working condition; the determination of the overturning moment in the stowed state and the maximum restoring moment in the non-working state are considered in detail in the work.
Loads on the rotation mechanism and departure changes. On fig. 2.15, A shown transverse (in the plane Y) and longitudinal (in the plane x) section of the pontoon after heeling at an angle q and trim angle ψ .
Weight G K the rotary part of the crane with the load has components S And S X, acting in the plane of rotation and determined by dependences of the form S Y \u003d G K sin q And S X \u003d G K sin ψ .
For a floating crane, the additional moment caused by roll and trim and acting on the rotation mechanism (Fig. 2.11) is determined by the formula
This expression can be explored to the maximum M φ. In particular, if the trimming moment component M ψ \u003d G K a - G 0 b \u003d 0(balanced pontoon), then the maximum M φ achieved at φ = 45o.
Forces S X And S have components acting in the boom swing plane and perpendicular to it. The components acting perpendicular to the boom swing plane create a moment that loads the rotation mechanism, the expression for which was obtained above. Total Strength T constituent forces S X And S in the swing plane of the boom is determined by an expression of the form T \u003d S X sin φ + S Y cos φ = G K ( sin q sin φ – sin ψ cos φ).
This force acts in the swing plane of the boom and is directed along the pontoon. On fig. 2.15, b weight decomposition shown G K for strength R, perpendicular to the main plane of the pontoon and taken into account in the calculations of the overhang change mechanism, and on the force T, parallel to the longitudinal axis of the pontoon and creating an additional load caused by roll and trim. Thus, in the center of gravity of each node of the rotary part of the crane (boom, trunk, etc.) weighing G i power arises T i caused by roll and trim. Additional moment M, the loading mechanism for changing the departure, is determined by the formula .
Loads due to inertial forces, acting on the crane during the transverse and longitudinal pitching of the vessel, are presented in detail in the works.
Unsinkability- the ability of the ship to maintain the minimum necessary buoyancy and stability after flooding one or more compartments of the hull. The calculation of unsinkability is presented in detail in the work.
Design features and characteristics of floating cranes
1. Cranes for river construction
For the construction of ports and bridges on inland waterways, universal floating cranes with a lifting capacity of 10 to 60 tons, collapsible cranes with a lifting capacity of 30-100 tons, pile cranes with a lifting capacity of 25-30 tons and combined land cranes installed on floating facilities are used.
Universal taps
Crane "Kirovets" type Kpl G / K 10-30 with a lifting capacity of 10 tons for all boom departures was produced by the plant. Kirov in Leningrad in clamshell and hook performance.
The crane is full-revolving, the boom of a lattice structure with a jib is pivotally connected to a movable counterweight for balancing. When changing the reach, the gooseneck moves in the opposite direction with respect to the boom (it lowers when the boom is raised), so that when the reach changes, the load remains at the same height.
The rotary part of the crane with the boom fixed on it and all lifting and turning mechanisms is located on rollers moving along the lower crown, located on a beam cage 2.1 m high from the deck.
AC crane motors with a voltage of 220-380 V, with a total capacity of 267 kw. Power is supplied by a diesel generator set located in the pontoon hull or on the shore. Crane control is electromechanical.
The crane is not self-propelled and moves with the help of mooring ends and winches.
To bring the crane into the transport position, the boom is lowered; after dismantling the mechanism for changing the reach of the boom, the height of the crane is reduced to 10 m.
The crane is designed for loading and unloading operations and therefore has high speeds of all operations. Due to insufficient carrying capacity, a crane is not recommended for installation work, but it can be used as an auxiliary crane at a concrete plant for supplying aggregates and cement from water, for unloading timber and other goods. With a small weight of the mounted elements, the crane can also be used for construction work.
Rice. 1. Scheme of a universal floating crane type Kpl G / K 10-30: 1-rocker and boom counterweight; 2-thrust for changing the reach of the boom; 3- engine room with control cabin; 4 - rotary mechanism
Crane company "Valmet" (Finland) built in 1958 with a lifting capacity of 10 tons (Fig. 2) full-revolving, equipped with a hook and grab.
Lattice crane boom 28 m long with a rack and pinion device for changing the reach. Cranes of this company are also produced with an arrow having a jib at the end.
The turntable of the crane with hoisting mechanisms located on it, the control cabin and the boom is installed on balancing carts moving along the rail rim laid on the beam pedestal on the pontoon deck. The movable part of the crane is attached to the fixed base by means of a hollow axial pin with bearings.
AC crane motors (380 V), independent for each movement. Crane control is electromechanical. The power plant consists of two diesel engines with a capacity of 180 hp each. With. with alternators of 150 kVA.
In the pontoon of the crane there are living quarters, and on the deck there is a dining room, a galley, a shower room, a pantry and other auxiliary rooms. The crane team consists of 11 people. during double shift work. The crane is not self-propelled and during operation it moves at the mooring ends.
The lowering of the crane boom on the pontoon for the transport position is not provided, therefore its height from the water in the unassembled state is 25 m, due to which the crane cannot pass under the bridges. When dismantling the boom, the height of the crane is reduced to 16 m, and when dismantling the lever device of the boom counterweight - up to 12 m. In this position, the crane becomes transportable on inland waterways.
Rice. Fig. 2. Scheme of the universal floating crane of the company "Valmet": 1 - lever device with a boom counterweight; 2-rack mechanism for changing the reach of the boom; 3- control cabin; 4 - diesel generator set; 5 - engine room
The crane is intended mainly for loading and unloading operations. At the construction of port and bridge structures, the crane can be used as an auxiliary crane for transshipment operations with bulk cargo and for the construction of berths from wooden and metal sheet piles and light types of reinforced concrete sheet piles and piles.
The Kpl 15-30 type crane (Fig. 3) is produced by the Teplokhod plant (USSR).
Full-revolving crane with one hook with a lifting capacity of 15 tons at all departures. The hook can be replaced with a grapple. The crane boom is pivotally connected to a movable counterweight, which greatly facilitates the change in reach.
The rotary part of the crane with all the lifting mechanisms and the boom rests on rollers rolling along the vein, mounted on a beam cage over the pontoon deck.
Three-phase crane electric motors 220/380 V are driven by a diesel generator set with a capacity of 375 kVA, located in the ship's hull (diesel type 84-23/30, generator MS 375-750). Pneumatic crane control. The team consists of 10 people. during double shift work.
Rice. 3. Scheme of a universal floating crane type Kpl 15-30: 1 - control cabin; 2 - lever device with a hydraulic drive for changing the boom; 3 - boom counterweight; 4 - machine room; 5 - rack for laying the boom in the transport position
The crane is not self-propelled and moves during operation with the help of electric capstans, and is towed over long distances. In the transport position, the boom is placed along the pontoon on a stand.
The crane is designed for river navigation conditions and is intended for processing loose and bulk cargoes. However, due to its characteristics, it can be successfully used for the construction of river berths from prismatic and tee reinforced concrete sheet piles. Thanks to its long reach, it can drive anchor piles, install anchor plates and install anchor rods. The large hook height allows them to load piles up to 20 m long. The crane can be used in combination with a crane with a large lifting capacity (50-100 tons), but with a smaller outreach and lifting height (for example, to install a vibration dampener for hollow concrete shells).
concrete walls of an angled profile during their construction "into the water". For the installation of sea berths and bridge work, the crane can only be used as an auxiliary crane if there is a crane with a larger lifting capacity.
Valmet cranes and type Kpl G/K 10-30 are available in small quantities and therefore their use is limited to the ports of registry. Bleichert cranes and type Kpl 15-30 have found wider application and are recommended for performing river hydrotechnical works.
In addition to the described cranes, a number of universal floating cranes with a lifting capacity of 30-60 tons are used in river hydrotechnical construction, which are mainly intended for offshore construction and are discussed below.
Collapsible cranes
Crane type PRK-30/40, designed by Lengiprotransmost, non-rotary, is assembled on a pontoons of 12 pontoons. The lifting capacity of the crane with a normal boom length of 32.5 m and an outreach of 2 m from the end (transom) of the ram is 40 tons, with a zero outreach - 45 tons. When installing a shortened boom with a length of 26.3 m, the lifting capacity at zero reach increases to 47.5 tons Auxiliary hook lifting capacity 10 t on all outreaches.
All crane structures are welded; heaviest weight element 4 t. The crane boom consists of two branches in the lower part, which then combine into one. The crane boom is connected by braces to a swinging A-shaped tubular strut 3. The change in reach is made by a chain hoist at a speed of 0.85 m/min. A pile driver with a telescopic strut can be attached to the upper part of the boom for driving piles weighing up to 12 tons with an 8-ton hammer. under the plashout and from the plashout. The crane is mounted on a frame consisting of I-beams and channels at bolted joints, laid on top of the pontoons and fastened to them.
Crane mechanisms consist of drive jib and cargo winches 1type UL-5 with a lifting capacity of 5 tons and a power plant type ZhES-60. Management of all mechanisms is concentrated in the cockpit. The crane is equipped with automatic load and boom limit switches. For anchoring and mooring operations, four drive winches of the UL-3 type with a lifting capacity of 3 tons, manual sleds for lifting anchors at the corners of the boat, bollards and bale straps are installed. The pontoon is surrounded by a fender and railing. To trim the crane, 40 tons of water (ballast) are poured into the aft pontoons. The movement of the crane is carried out by two motor pontoons, which are part of the scaffold. The permanent crane team consists of 5 people. in shift.
Rice. 4. Scheme of a floating crane type PRK-30/40: 1 boom; 2 boom brace; 3- swinging strut; 4 - boom chain hoist; 5 - boom winch; 6 - power plant ZhES-60; 7 - cargo winches; 8 - beam cage (frame) of the crane; 9- anchor katbalki; 10- water ballast; 11- telescopic strut of the pile boom; 12 - copra hanging boom; 13 - mooring winches; 14 - control cabin
The crane is designed for river conditions with the navigation area "P" (large rivers). Freeboard height during operation 0.19 m.
The height of the crane with the lowered boom is about 14 m, and with the lowered boom strut about 6 m.
Mounting and dismantling of the crane is carried out by truck cranes of types K-52 and K-104. To transport the crane, 12 MAZ-200 and four ZIL-150 vehicles are required.
The PRK-30/40 crane is easy to manufacture and assemble and is intended mainly for the construction of temporary bridges (including the installation of superstructures). It can also be used in the construction of supports for permanent bridges and river hydraulic structures.
The main disadvantages of the crane are the lack of rotation of the boom and the low speed of lifting the load and the boom, which sharply reduces its performance compared to universal full-slewing floating cranes.
The PRK-100 type crane is manufactured by the factories of the Ministry of Transport Construction according to the project of Lengiprotransmost. The crane is assembled on a pontoon of 24 pontoons of the KS-3 type (main assembly). The load capacity on the main hook is 100 tons. With this load capacity, the crane works as a fixed crane. On the auxiliary hook with a lifting capacity of 30 tons, the crane operates with a rotation of 90 ° in both directions from the longitudinal axis. The crane can also be assembled on 16 pontoons (lightweight assembly); at the same time, it works as a fixed one with a maximum load capacity of 70 tons.
The crane boom is two-branch welded, consists of four elements 8-11.5 m long, assembled on bolts. The boom is fixed on the hinge of the turntable and is held by a link brace, which transmits force to the strut 9 and the stretched counterweight strut. The change of departures is carried out by a boom chain hoist.
The upper swing frame consists of bolted I-beams. All cargo, boom and rotary winches, power plant and control panel are installed on the frame. The swivel frame moves on four balancing carts of two rollers each along a 12 m diameter rail mounted on a distribution frame. The rotary part is fixed to the lower distribution frame by a central pin with bearings.
The crane is equipped with load and roll limiters and limit switches for load, boom and slew. Wedging devices are installed on the distribution frame, which ensure turning off when the crane is operating with a load of more than 30 tons and during “lightweight assembly”. The crane mechanisms consist of UL-8A traction winches for the main and auxiliary hooks. The turn is carried out by a winch with a pulling force of 20 tons. The diesel generator set is represented by diesel engine 1-D-150AD with a capacity of 150 liters With. and a PS-93-4 generator with a power of 75 kW of alternating current, a voltage of 230 V.
At the same time, the cycles of auxiliary lifting and turning or lifting of the boom, lifting of the boom and turning, mooring operations and turning or lifting of the boom, or auxiliary lifting can be combined.
Rice. 5. Scheme of a floating crane type PRK-100 (main assembly): 1- boom; 2-link boom guy; 3- boom chain hoist; 4 - rack; 5 - counterweight; 6 - windlass anchors; 7 - distribution frame; 8 - upper swivel frame; 9 - brace; 10 - control panel; 11 - power plant; 12 - 15 - winches, respectively, cargo, rotary, boom and mooring; 16 - ballast pontoons
Four mooring winches of the UL-5 type with a pulling force of 5 tons and a cable speed of 5 m/min are installed on the platform. The pontoon at the corners is equipped with guides in the form of rollers and bollards, catbales for lifting anchors, two Hall anchors weighing 400 and 300 kg, lifted by a windlass, a fender and a railing. Two pontoons of the pontoon 16 are filled with water to trim the crane. Residential and household premises on the crane are not provided.
While moving with a load, the crane is towed by a vessel with a capacity of at least 600 hp. With. The crane can operate with a wave of no more than 1 point, since the deck rises above the water by only 0.3 m. Considering that the height of the crane, even with a horizontally lowered boom, is 16 m, it must be partially or completely disassembled during transportation.
CranPPK-100 is designed for immersion of shells, installation of prefabricated supports and suspended installation of reinforced concrete superstructures, as well as for the construction of river port facilities. The disadvantages of the crane are a decrease in carrying capacity of up to 30 tons when turning and low speeds of all movements (two times slower than universal floating cranes). Installation reinforced concrete structures weighing over 30 tons, requiring high aiming accuracy, in the absence of a turn, must be carried out by mooring winches, which is very difficult. Therefore, the use of this crane should be considered as temporary until the creation of universal floating cranes with a lifting capacity of 50 - 100 tons for river conditions.
2. Cranes for offshore construction
For the construction of breakwaters, moorings and fortification of sea coasts in the USSR, universal floating cranes with a lifting capacity of 30 to 100 tons are mainly used. In some cases (for example, when building foundations for oil rigs in the Caspian Sea), a 250-ton floating crane is used. Abroad, in the construction of massive piers, floating cranes with a lifting capacity of 200-400 tons are used.
Rice. 6. Crane load curves PRK-U0: 1 - main hook; 2- auxiliary hook; 3- main hook for light assembly
Universal cranes with a lifting capacity of 30-60 tons
Crane firm "Tournay" (USA) release 1940-1945. full-revolving with two hooks 30 and 8 tons (Fig. 7). The small hook can be replaced by a grapple. Lattice boom; the change in the reach of the arrow is made by the chain hoist. The engine room with cargo winches, boom, engine and control cabin rotates on rollers along a crown mounted on a beam cage over the pontoon deck.
Rice. 7. Scheme of a floating 30-ton. crane "Tournay": 1 - engine and diesel rooms; 2- jib for fastening the fixed block of the chain hoist of the boom; 3 - control cabin; 4 - rotary roller device; 5 - stand for laying the arrow in the stowed position
The crane is not self-propelled and its movement during operation is carried out at the mooring ends by electric capstans. The power of the main diesel engine of the installation is 150 l. e., auxiliary - 80 l. With.
In the crane pontoon there are residential and service premises and a fuel tank. The crane is serviced by a team of 19 people. during three-shift work.
Due to the relatively low carrying capacity and the lack of own power, the crane in sea port construction is used as an auxiliary crane in combination with a crane of a larger carrying capacity and in a water area closed from waves. It is also suitable for the construction of river port facilities - it is convenient for them to load tee and rectangular reinforced concrete sheet piles and shells with a diameter of 1.6 m, up to 16 m long. 1 km in Ust-Donetsk port.
In addition, the crane can be used in bridge construction for dipping shells, installing frames and mounting supports within its load characteristics.
The disadvantage of the crane is its high height in the transport position - 18 m from the water horizon. However, it can be reduced to 12 m by dismantling the fixing structure of the fixed boom blocks.
The self-propelled 50-ton crane "Bleichert" (GDR) was widely used in the seaports of the USSR for loading and unloading and construction work.
The crane is full-revolving, equipped with three independent lifting hooks: the main one with a lifting capacity of 50 tons, the auxiliary one - 10 tons, which can be replaced by a grab, and the second auxiliary one - 5 tons, moved on a trolley along the bottom of the boom ("cat").
Hooks of various capacities give the crane versatility and economy, as small loads are processed by light capacity hooks without wasting power for idle operation of the main cargo winches.
Lattice crane boom with chain hoist for changing outreaches. The engine room with lifting mechanisms, control panel, boom and permanent counterweight is located on a turntable, which rotates around the axial pivot pin on rollers connected by a cage. The rollers roll along the crown, mounted on a beam cage, over the deck of the pontoon.
The total power of electric motors for cargo operations and turning is 300 kW; DC voltage 220 V. The ship's hull is equipped with three diesel engines (one in reserve) with a capacity of 150 hp each. With. each, which work on DC generators and propeller shafts.
Crane work is allowed at a temperature not lower than -25 °. The team consists of 22 people. during double shift work.
According to its characteristics, the crane can be used in the construction of sea and river berths from prefabricated unified reinforced concrete elements. In bridge construction, the crane is suitable for immersion of shells, installation of block supports and installation of elements of prefabricated reinforced concrete superstructures.
The excessive bulkiness of the crane (weight 543 tons, width of the pontoon 20 m, height of the crane in the transport position 15 m) limits its passage through inland waterways only of the 1st class and then in low water.
Rice. 8. Scheme of a self-propelled floating 50-ton crane "Bleichert": 1 - grab (or hook); 2 - "cat"; 3 - boom chain hoist; 4 - emphasis of the minimum overhang limiter; 5 - pu; y>t control; in - assembly crane; 7- machine room; 8 - counterweight; 9 - rotary roll device; 10 - stand for laying the boom
Full-revolving floating 50-ton crane of domestic production, like the Bleychert crane described above, is equipped with three independent lifting hooks: the main lifting capacity is 50 tons, the auxiliary one is the Yuti hook on the "cat" - 5 tons.
The engine room of the crane with the boom, counterweights and control panel is located on a roller turning circle, placed on a stand 5.4 m high from the pontoon deck. Thus, a significant under-boom dimension was created, which is necessary for the production of cargo and shipbuilding works, for which purpose the crane was designed.
A feature of the crane is a very rational design of the boom and the metal structures of the crane. The boom in the form of a triangular diagonal truss is held by a boom chain hoist and a 40-ton double-acting movable counterweight, which on large
departures creates a force on the boom that is the opposite of the load moment, and thereby lightens the load on the boom winch. At low overhangs, the counterweight force corresponds to the load moment, due to which the boom is kept from tipping over towards the counterweight, which is especially important in rough seas and no load on the hooks. The metal structures of the crane are made of separate large sections, taking into account the requirements for quick installation and dismantling.
Rice. 9. Scheme of a full-revolving floating 50-ton crane: 1-rope chain hoist for changing the boom; 2 - control panel; 3- counterweight; 4-stand; 5 - stand for laying the boom
In the transport position, the crane boom descends along the pontoon onto the rack, however, due to the high location of the engine room and the fastening of the boom fixed blocks, the height of the crane is about 26 m from the water horizon. When dismantling the mechanism for changing the reach of the boom, the height is reduced to 17 m.
The crane is self-propelled two-screw. The power plant consists of two ZD-6 diesel engines and DC generators with a capacity of 100 kVA each. In addition to them, there is a backup engine. For all movements and propellers, independent electric motors are installed. The power plant is located in the pontoon hull, where there are also rooms for the crew, domestic and service needs. The crane is equipped with automatic outreach and load capacity indicators. Crane weight 422 t.
A full swing crane can be successfully used in the construction of offshore hydraulic structures.
Floating 60-ton crane of the company "Dravo" (USA) manufactured in 1941 - 1945. full-revolving non-self-propelled with an arrow in the form of a three-dimensional truss with a triangular lattice. Change of departures of an arrow is made by a polyspast. Two hooks with a lifting capacity of 60 and 15 tons are installed on the boom. The latter can be replaced by a grab.
The engine room of the crane with a boom fixed on top, a control cabin and a counterweight rotates on a roller turntable resting on the pontoon deck. The Atlas diesel engine with a capacity of 275 hp is used as the prime mover. With. On many cranes, these diesel engines have been replaced by domestic ones. Pneumatic crane control. The movement of the crane during operation is carried out by electric spikes installed at the corners of the pontoon. The welded hull is divided by a network of watertight bulkheads. Auxiliary, residential and household premises are located inside the pontoon.
Rice. 10. Scheme of a floating 60-ton crane "Dravo": 1 - jib pulley block; 2 - crane operator's cabin; 3 swivel roller crown; 4 - rack for laying the boom
In the stowed position, the crane boom is lowered along the pontoon onto the stand. However, due to the high location of the attachment of the fixed blocks of the boom, the transport height of the crane from the water is about 22 m. After partial disassembly, the height of the crane can be reduced to 16 m.
Cranes of this type are very simple in design, easy to operate and can be successfully used in offshore construction in areas protected from waves.
The disadvantages of the crane include a large transport height and a large width of the pontoon (18.8 m), which limits its use in river construction (passage through inland waterways only of the 1st class, and then with partial disassembly of the upper structure).
Floating full revolving 60t crane ( domestic project) has two hooks: the main hook with a lifting capacity of 50-60 tons and the auxiliary hook - 15 tons, which can be replaced by a grab.
The crane boom (Fig. 11) of the shape of a trihedral pyramid consists of three solid section belts connected by ties. The change 110 of the boom departure is made by a cable pulley block. The boom has a movable counterweight. The lower swivel joint of the boom is located at a height of 14 m above the water level, which provides a large under-boom clearance required for loading cargo on high-sided vessels. The engine room of the crane with lifting mechanisms, movable and fixed counterweights, boom and control panel is located in the stern of the vessel and rotates on the column (on vertical and horizontal bearings). As an energy source, two DGR-300/500 diesel generators with a capacity of 300 kW each, alternating current with a voltage of 380 V, are installed in the ship's hull.
Rice. 11. Scheme of a full-revolving floating 60-ton crane (domestic project): 1 - boom tackle; 2 - support bearing of the central column; 3- crane control panel; 4- wheelhouse of the vessel; 5 - boom stand; 6 - wing-shaped engines; 7 - machine room of the crane; 8 - movable boom counterweight
The crane is designed for sea conditions works with waves up to 2-3 points and wind up to 6 points. The crane vessel has ship contours and moves at a speed of up to 11 km/h, with high maneuverability.
In the transport position, the crane boom is lowered onto the stand and located along the deck. In this position, the height of the crane from the water level is about 21 m. With partial dismantling of the structure for fastening the fixed blocks of the boom and lowering the boom itself, the transport height can be reduced to 14.5 m. and wind up to 5 points. Crane towing without dismantling can be carried out with waves not exceeding 5 points and wind 6 points.
The displacement of the crane in the transport position is 1080 tons. The crane team consists of 14 people. for double shift work. The crew quarters, located in the ship's hull, are equipped with an air conditioning system and are finished with plastic. The crane vessel is equipped with mooring and anchor devices, fire-fighting and rescue equipment in accordance with the norms of the USSR Maritime Register.
According to their characteristics, universal floating cranes with a lifting capacity of 30-60 tons are widely used in the practice of sea port construction.
Universal cranes with lifting capacity 90 - 100 t
Floating crane from Dravo (USA) with a lifting capacity of 90 tons (Fig. 12) on the main hook and 20 tons on the auxiliary hook. The diesel-electric crane is not self-propelled and is similar in design to the 60-ton crane of the same company described above, but has somewhat larger dimensions. The power plant is represented by two diesel generators of 125 kW each.
Rice. 12. Floating 100-ton crane of the company "Dravo": 1 - pontoon; 2-control panel; 3- arrow; 4 - main 90-t hook; 5 - auxiliary hook; b - a stand for laying an arrow; 7 - jib for fastening fixed blocks of the boom
The height of the crane in the transport position is about 22 m, which makes it difficult to use it on inland waterways and limits its use only to the construction of marine hydraulic structures.
Floating crane "Hans" built in 1949 (plant named after Georgiu-Dezh, Hungary) with a lifting capacity of 100 tons on the main hook and 35 tons on the auxiliary hook at all boom departures.
The boom of the crane with a length of 35 m of a through design is reinforced on! hinge at a height of 13 m from the pontoon deck. Departure change! The boom is made with the help of two propellers driven by electric motors. The use of a grapple is not provided.
Rice. 13. Scheme of a floating 100-ton crane "Hans" built in 1949: 1 - boom; 2 - control cabin; 3- support roller bearing; 4 - central column; 5 - counterweight; 6 - screws for changing the reach of the boom
The rotary part of the crane is located in the form of a dome on a pyramidal column 8.5 m high from the deck, on which, as it were, the entire rotating part of the crane is put on. At the bottom of the column at deck level, a turntable is fixed, and on the rotating part of the crane there are gears for turning.
The crane engine room, counterweight, boom and control panel are located on the rotating part of the crane.
In the all-welded hull of the vessel (pontoon), two diesel engines of 100 liters each are installed. With. with DC generators and auxiliary diesel 24 hp. With. with a generator for parking. In the pontoon there are living and amenity premises for the team, as well as tanks for fuel, fresh water, etc. The crane is self-propelled and has two propellers. For mooring operations, four electric capstans are installed at the corners of the pontoon. The crane boom does not descend onto the pontoon and in the transport position is inclined at an angle of 25° to the horizon.
The main purpose of the crane is the completion of ships and the loading of heavy cargo, in connection with which a high jib clearance is provided. Because of low speeds performing operations, the crane is inefficient when assembling prefabricated structures and can be more successfully used when reloading reinforced concrete elements and arrays from factories and landfills onto floating facilities. It is also advisable to use the crane in cases where it is necessary to deal with particularly long, but relatively light structures, since the lifting height above the water for a 35-ton hook is 40 m. Due to its bulkiness, the crane cannot be used for river construction purposes, as well as in the field of bridge building.
The floating crane "Hans", built in 1956 by the same factory as the previous crane, has a lifting capacity of 100 tons on the main hook and 25 tons on the auxiliary one. The boom of the articulated type crane with a lattice structure has a jib moving in the opposite direction of the boom, due to which the load hooks are almost at the same height at all departures. The change in the outreach of the boom is made by a screw system with partial balancing by a moving counterweight.
Rice. 14. Scheme of a floating 100-ton crane "Hans" built in 1956: 1 - screw mechanism for changing the boom; 2 – movable counterweight 124 t; 3- machine room; 4 - support column; 5 - control panel
The rotary part of the crane is made similar to the 1949 type crane described above. The all-welded crane pontoon is divided into 15 compartments by watertight bulkheads, which ensures the unsinkability of the crane even when two compartments are filled with water. Two diesel engines of 160 liters each installed inside the pontoon serve as an energy source. With. with DC generators and two auxiliary diesel generators of 24 liters each. With. every. The crane has two screws driven by electric motors with a capacity of 100 kW each. Movement over short distances is carried out with the help of electric spikes.
In the transport position, the crane boom does not fit, so the windage and surface dimensions of the crane are very large.
According to its characteristics, the Hans 100-ton crane (1956), in comparison with other described 100-ton cranes, is the main one for the construction of sea berths, breakwaters and bank protection structures, although in its design it is more suitable for shipbuilding and loading and unloading operations .
At the same time, the “Hans” crane has an insufficient height of the outlet of the main and auxiliary hooks, which at working departures, taking into account the roll, is about 25 m, which is not enough for inserting shells 24 m long into the guides, which are widely used in the practice of hydraulic engineering construction. The relatively low power of the engines and the large windage of the crane require the use of 400-500 hp tugs for its movement even in closed port waters. That is, which dramatically increases the cost of a machine-shift crane. The impossibility of moving a crane along inland waterways from one sea basin to another and working on rivers and reservoirs also belongs to its disadvantages. The absence of a grab does not allow the crane to carry out underwater digging of soil, which is necessary for the construction of bank protection structures in open water areas and in a number of other cases.
The crane is serviced (due to the lack of remote control) by a team of 22 people. during double shift work.
Unique floating cranes
Unique are universal cranes, which are distinguished by a significant lifting capacity, reaching 250 - 350 tons. Such, for example, are the cranes of the Krasnoye Sormovo plant and the Demag company.
The lifting capacity of the main hook is 250 tons, the auxiliary hook is 140 tons. In addition, a “cat” with a hook with a lifting capacity of 10 tons moves along the crane boom.
The crane is full-revolving under all loads. The crane boom, 72 m long, consists of three powerful belts with a triangular lattice and transverse links along the lower belt. The change in the reach of the boom is carried out by two 16-thread chain hoists. The boom has a movable counterweight that prevents it from swinging when rolling. The boom is fixed at a height of 24.5 m from the deck, which provides a large under-boom dimension and a large lifting height of the hooks.
The superstructure of the crane with the engine room, counterweight, boom and control panel can be rotated on a column fixed in the ship's hull.
Two crane ships are connected by a catamaran-type bridge for greater stability, since the crane is designed to work on the high seas, while its own weight reaches 2080 tons.
The crane is located on the left vessel; on the right vessel there are two power diesel-electric units with a capacity of 4400 /se/l, serving the ship's movement mechanisms, and one 1500 kW - for crane mechanisms. There are also cargo holds, water and fuel supplies. The paired system of ships allows to have a large cargo deck area necessary for the transportation of spatial structures of oil rigs, etc., and also provides high seaworthiness compared to single pontoons of floating cranes. Due to the great stability, crane operation is allowed with waves up to 4-5 points (wave height up to 3 m) and wind force 6 points, and movement - with waves up to 6 points (wave height up to 6 m) and wind up to 8 points.
Rice. 15. Scheme of a floating self-propelled 250-ton crane on twin ships: a - working positions; b - transport position; 1 - chain hoist boom; 2 - movable boom counterweight; 3 - machine room of the crane; 4-central column; 5 - running ship cabin; 6 - crane control panel; 7 - support bearing; 8 - stand for an arrow
Propellers located at the stern and bow of each vessel provide high maneuverability for the crane, which is necessary for precise installation at work stations. During transitions, a crane is operated from the wheelhouse, located at a height of 13 m from the deck. In the stowed position, the crane boom is lowered and positioned at an angle to the longitudinal axis of the vessel, fixing it on a stand on the bow of the starboard vessel. For docking, the ships are separated and independently brought to the dock. The crane is equipped with a warning alarm and protective devices against overloads exceeding the calculated ones. Remote and automatic systems are used in crane control.
Crew cabins and service rooms located in the ship's hull are provided with air conditioning, hot and cold water and other amenities.
Floating self-propelled 350 Demag crane was built in Germany in 1938-1940. With its lifting capacity, size and engine power, this crane is also one of the largest floating cranes in the world.
The lifting system consists of two 175-ton main lifting hooks connected by a traverse, two 30-ton auxiliary lifting hooks moving on a trolley along the boom beam (jib), and a 10-ton cat hook moving along the boom.
The crane is full-revolving under all loads. The crane boom, about 80 m long, of an articulated structure, has two enclosing rocker arms and a movable counterweight weighing 200 tons. The boom outreach is changed by a screw mechanism. The rotating part of the crane is planted in the form of a bell on a pyramidal column fixed in the pontoon body. The supporting roller bearing on the head of the column, on which rotation takes place, has a diameter of 2.5 m and can withstand a load of 2100 tons.
The three-story crane engine room with a permanent 400-ton counterweight, boom and control panel is located on the rotating part of the crane. The ship's hull - a pontoon - is divided by waterproof partitions into 35 compartments. On the deck there is a platform for cargoes measuring 20 × 26 m. For the movement and maneuverability of the crane, three water propellers of the Voith-Schneider system are installed - two at the stern and one at the bow of the vessel. Electric capstans are provided for mooring operations at the corners of the pontoon.
Rice. 16. Floating self-propelled 350-ton crane of the company "Demag": 1 - nock of the boom; 2 - boom rockers; and a movable 200 counterweight; 4 - screw mechanism for changing the boom reach; 5 - three-story engine room with a 400-ton counterweight; 6 - rotary mechanism; 7 pyramidal support column; 8 - control panel
The central power plant, located inside the pontoon, consists of three diesel generators with a capacity of 800 kW each and an auxiliary diesel generator of 225 kW alternating current. There are also cabins for 23 people. teams, storage and utility rooms and a workshop.
The total weight of the crane is 5,000 tons, the height from the water horizon with a raised boom is about 115 m, and the load moment is 10,500 tm.
The main purpose of the crane is shipbuilding and ship lifting. It can also be used for construction purposes.
In total, several cranes of this type were built, one of which is operated in the USSR on the Baltic Sea.
Floating cranes abroad
In foreign practice, in recent years, a number of very advanced floating cranes have been built, designed both for the purposes of offshore hydraulic engineering construction and for performing transport work.
A floating crane manufactured by Hokodate Doc (Japan) with a lifting capacity of 50 tons was built in 1962 for the construction of ports.
The boom of a flat-type crane consists of two branches connected by ties. In addition to the main hook, the boom has a second hook with a smaller capacity. Change of a departure of an arrow is made poly-spasty. In the transport position, the boom is laid along the pontoon and on the stand located at the stern.
Rice. Fig. 16. Scheme of a floating crane from Hokodate Doc with a lifting capacity of 50 tons: 1 stand for laying the boom; 2 - room for diesel generators; 3 - mooring winches; 4 - room for lifting mechanisms; 5 - control panel
The engine room with lifting winches, control panel, counterweights and boom rotates on paired balancing rollers moving along a crown mounted on the pontoon deck.
Self-propelled diesel-electric crane with two diesel engines of 180 hp each. With. each located in the deck superstructure. There are also crew quarters, a galley and a shower room. The pontoon hull is equipped with electric winches and mooring arrangements for crane movement over short distances.
The same company built a non-self-propelled floating crane of a similar design, but somewhat smaller and with a lifting capacity of 30 tons.
The Samson floating maneuverable crane with a lifting capacity of 60 tons was built by Forged Sheldon and Co. in Carlyle (England).
Diesel-electric full-revolving crane with a screw mechanism and a moving counterweight to change the reach of the boom, with independent engines for each mechanism.
The body of the crane is all-welded with ship contours, divided into nine watertight compartments. In the aft part, the deck is reinforced to receive cargo with a total weight of 200 tons.
The crane is equipped with a high-speed auxiliary winch and a second hook with a lifting capacity of 20 tons, respectively, with a larger radius of action than that of the main lifting hook. The electrical control, made according to the Ward-Leonard system, allows you to increase the speed of the main lift of the crane for handling loads less than the maximum weight.
Rice. 17. Floating maneuverable crane "Samson" with a lifting capacity of 60 tons: 1 - auxiliary 20-ton lift; 2- main 60-t lift; 3 - screws for changing the boom reach; 4- boom mobile 81 - t counterweight; 5 - engine room with a fixed 128 t counterweight; 5 - control panel
A design feature of the Samson is a maneuvering device in the bow, consisting of a large centrifugal pump that sucks water from under the hull and throws it to any side, depending on the direction of rotation. Together with two 10.4 m parallel stern propellers and two streamlined rudders, this device provides the crane with maximum maneuverability even at low speeds and allows it to stop precisely at the berths and move without a tow.
The upper structure of the crane is mounted on a swivel frame, on which the supporting elements of the boom, lifting mechanisms and a 128-ton counterweight are also located. The boom is lifted by two belt-threaded augers that work in sync. The lifting screws are completely covered with steel sliding covers to protect them from rain and dirt. The boom does not lower to the deck and therefore the smallest transport height of the crane is 40 m.
The main and propulsion engines consist of two diesel engines of 900 hp each. With. each connected to the main and auxiliary DC generator. The power of additional generators is designed to ensure the operation of the entire crane, even with some margin.
Due to its high navigable qualities, the crane is convenient for working in open water areas during the construction of piers, breakwaters and bank protection structures.
Rice. 18. Scheme of a floating 100-ton crane from the Ornstein Koppel company: 1 - boom; 2 - control panel; 3 - wheelhouse; 4 - rotary mechanism; 5 - engine room with fixed counterweight; 6 - mobile counterweight; 7 - thrust bearing
A floating 100-/I crane from Ornstein Koppel (Germany) is equipped with two main hooks with a lifting capacity of 50 tons each (Fig. 62). Both hooks are connected by a common traverse. Hook lifting mechanisms work synchronously. In addition to the main ones, there is an auxiliary \b-t hook with an independent lifting winch.
The jib of the lattice crane is 42 m long. The jib boom is changed by two propellers driven by an electric motor. The weight of the boom is significantly balanced by a 40-ton movable counterweight pivotally connected to it. Half of the tipping moment from the working load is balanced by a 164-ton counterweight located behind the engine room.
The upper rotary part of the crane in the form of a dome is supported by a roller bearing on a support column fixed in the ship's hull. Attached to the bottom of the column is a slewing ring with a gear that rotates the top of the crane 360°.
In the all-welded hull of the vessel there are two diesel engines with a capacity of 200 liters each. With. at 750 rpm. The diesel shafts are connected at one end to three-phase current generators with a power of 130 kw, synchronously operating on lifting mechanisms, and at the other end - to propeller shafts. For work in the parking lot there is an additional diesel generator set 90 kW. The crane is equipped with devices for indicating the weight of the load, the reach and the height of the load hook.
In the transport position, the boom is lowered to a horizontal position and fixed on a support post, while the windage and height of the crane are sharply reduced, so that it can be transported without dismantling in tow by sea even in heavy seas, which was confirmed when the crane moved to its destination, from Hamburg to the Iraqi port of Basra.
According to its characteristics, the crane is very convenient for servicing offshore hydraulic engineering construction.
Floating crane from Krupp (Germany) with a lifting capacity of 150 tons on the main hook and 30 tons on the auxiliary hook.
The boom of the articulated type crane is made in the form metal structure with solid walls, which gives the crane a modern appearance.
The slewing structure and load balancing system are the same as those of the Ornstein Koppel 100-gauge crane above. To move over long distances, the crane boom is lowered to a horizontal position with a special screw device. Vessel hull (pontoon) is all-welded. The power plant consists of two main 500 hp. With. and two auxiliary diesel engines of 156 liters each. e., associated with generators of current. The crane ship is propelled by two diagonal propellers of the Voith-Schneider system. The pontoon deck provides for the possibility of loading cargo on it with a total weight of up to 300 tons.
The crane is intended mainly for loading and unloading operations in ports and for the needs of shipbuilding. It can be used in marine hydrotechnical construction, but only in ports with closed water areas, since the significant height of the crane in the transport position (about 30 m) creates a large windage and makes it difficult to maneuver the crane in wind and waves.
Rice. 19. Floating 150-ton crane company "Krupp"
A floating 250-ton crane from Ornstein Koppel (Germany) was built for the port of Buenos Aires (Brazil) in 1956-1958.
The crane has two main hooks with a lifting capacity of 125 tons each, united by a traverse for lifting loads with a total weight of up to 250 tons, and two auxiliary hooks with a lifting capacity of 40 and 10 tons. The latter moves along the boom on a "cat".
Rice. 20. Floating 250-ton crane from Ornstein Koppel
The crane operates as a full-revolving crane with a load of up to 150 tons, while changing the outreach of the boom with the load is allowed. With a load of 150 to 250 tons, it is possible to turn the crane only 22 ° 30 'in both directions from the longitudinal axis without changing the outreach of the boom with the load. The largest load moment of the crane is 5125 m.
The superstructure of the crane with boom, machine room with lifting winches, counterweights and control panel rotates on a powerful axial roller bearing running in an oil bath. The bearing is mounted on a pyramidal column fixed in the pontoon. Horizontal forces from the upper structure of the crane are transferred to a horizontal bearing, consisting of a ring with a diameter of 5.7 m and eight rollers combined in pairs. Such a device greatly facilitates turning, but increases the dimensions of the crane and is used, as a rule, in German cranes with a lifting capacity of over 100 tons.
The boom of a lattice crane is riveted. Change of a departure of an arrow is carried out by two polyspasts. The boom is partially balanced by a counterweight.
The crane is not self-propelled and for its movement there are four drive capstans with a force of 6 tons and a cable hauling speed of 12 m/min. Due to the lack of its own power, the power plant of the crane consists of only two diesel engines with a capacity of 185 and 260 hp. With. and three DC generators 2 × 110 + 60 kW with a voltage of 230 V. For own needs in the parking lot there is an auxiliary diesel generator with a capacity of 22.5 liters. With. All nine crane motors are of the same type with a capacity of 44 kw each at 750 rpm.
The crane is controlled from a central console located at a height of 14 m from the deck. Automatic devices are provided to prevent crane overload, and electric interlock in case of incorrect actions of the crane operator.
The crane pontoon is welded, divided by waterproof partitions into 18 compartments. On the deck of the pontoon, a platform 9.5 × 9.5 is provided for receiving cargoes up to 10 t/m2. Inside the pontoon are diesel generators, living cabins for 12 people. crew, household and storage rooms and a workshop.
In the transport position, the crane boom is lowered to the deck with its own chain hoists and fixed, and the upper structure is wedged with hydraulic jacks, which unloads the axial bearing. In this form, the crane can be towed by sea at a speed of 5-7 knots (up to 13 km/h). The height of the crane in the transport position is about 32 m above the water level.
This crane is intended for transport work, but can also be successfully used for the construction of piers, piers and piers from large elements and heavy arrays.
3. Floating head cranes
As cranes for hydraulic engineering and bridge construction, floating headframes with inclined booms can be used, the departure of which overboard the pontoon can be in the range from 3 to 9 m with a corresponding carrying capacity of 30 and 10 tons. therefore, head cranes are usually fixed.
In this area, the most common impact drivers with swinging arrows, for example, the impact driver of the SSCM-680 type from the Nillens company, etc.
The SSSM-680 headframe mounted on a pontoon can be used as a floating crane when the boom is located along the pontoon at outreaches up to 9 m from the end of the pontoon. Koper is not self-propelled. The energy source is a steam boiler with a heating surface of 50 m2 at a steam pressure of 6-8 kg/cm2. Lifting mechanisms - steam winches.
Mooring operations are carried out with hand winches. Inside the pontoon there are residential and utility rooms for 10 people. copra teams.
In the transport position, the boom is rotated and placed along the pontoon on a stand.
Floating pile driver of the company "Nillens" (Belgium) is not self-propelled. The boom is located in the bow of the pontoon on a platform that rotates 180°. Crane work and pile driving are allowed only when the boom is located along the pontoon. In this case, the maximum reach of the boom from the end will be 6.5 m.
Rice. Fig. 21. Scheme of installation of the Nillens copra: a - for the operation of the copra; b-for crane operation; 1-farm with an arrow; 2-drum winch; 3- steam boiler; 4 - pontoon; 5 - steam hammer; 6 - stand for laying an arrow; 7-ballast water tanks
All copra mechanisms are steam and are provided with steam from a boiler with a pressure of 8 kg!cm2. The boiler is located on a turntable and is at the same time a counterweight to the boom with a hammer. To bring the copra to the stowed position, the turntable with the boom and the boiler is rotated 180 ° and the boom is lowered by means of a special mast and chain hoist onto a stand located at the stern of the pontoon. The pontoon has ballast compartments, fresh water tanks and storage facilities. Cabins for the crew are located on the deck. During operation, the pile driver moves at the mooring ends with the help of winches and bollards.
The floating pile driver of the Jübigau plant (GDR) is the most modern. The swinging boom of a copra together with a steam boiler (heating surface 34 m2 and pressure up to 10 kPcm) is located on a turntable rotating through 360° (in the bow of the pontoon). The copra boom can take a forward inclination of 1/10 when located across the pontoon and 1/3 - along the pontoon.
Steam provides only the operation of the hammer when driving piles, the rest of the mechanisms are electrically driven by a diesel generator with a capacity of 57 kw. In addition, there is an auxiliary diesel generator 12 kW for own needs when parking.
Koper is not self-propelled. In the transport position, the boom is rotated by 180° and lowered by a special mast along the pontoon to the stand.
The copra pontoon houses fresh water tanks, ballast compartments, a fuel bunker and storage facilities. The pontoon is equipped with mooring devices and crew quarters.
TO Category: - Cranes for bridge construction
In 1964, Lengiprotransmost developed a project for a floating crane PRK-100 with a lifting capacity of 100 T intended for installation and loading and unloading operations at the construction of bridges and at construction sites near water bodies.
The crane is collapsible, the maximum weight of an individual element does not exceed 7 T. The crane can be transported to the construction site as per railway, and by road transport, since all elements of the crane fit easily into the railway and road dimensions.
The crane is mounted on a pontoon of 24 pontoons of the KS type, prepared in advance at the construction site. It takes 12 - 15 days to assemble the crane topside on a ready-made ramshoe if there are 10 tons of erection cranes (automobile or floating). The dismantling of the crane is carried out in 10 - 12 days.
The PRK-100 crane is equipped with two hooks: the main lifting capacity is 100 tons and the auxiliary lifting capacity is 30 T. With a load on the hook up to 30 T the upper part of the crane can be rotated 90° in both directions. Turning is carried out with the help of a winch mounted on a pontoon. With a load weighing more than 30 T the crane rotates along with the ram. At the same time, jamming devices are installed under the support hinges of the boom and in the rear part of the turntable. Crane maneuvers on the water are provided by four papillon winches equipped with rope layers, as well as all the equipment necessary for papillon work.
All winches of the crane, including 3 cargo and 1 jib, are powered by our own AD-75T/400 power plant with a capacity of 75 kW installed on the crane ram. The control of electric drives is concentrated in the crane operator's cabin.
The PRK-100 crane differs from the existing universal floating full-turn cranes in its low weight, assembly, and small draft. The cost of its manufacture is 6 times less than that of universal cranes, it is served by 4 people instead of 10.
A prototype of the PRK-100 crane, manufactured by the Uglich Mechanical Repair Plant, has passed all tests and is operated by Mostootryad No. 11 in Leningrad on the river. Neva for 1.5 years. The acceptance committee of the USSR Ministry of Transport and Construction recommended it for mass production.
| Structural diagram of the crane PRK-100 |
Technical characteristics of the crane PRK-100
| The highest load capacity, ts: | |
| on the main hook | 100 |
| on auxiliary hook | 30 |
| Useful reach of the boom (from the side of the ram), m: | |
| loaded 100 T: smallest | 3 |
| . loaded 100 T: largest | 10 |
| . loaded 30 T: smallest | 5 |
| . loaded 30 T: largest | 22 |
| Lifting height of the hook from the surface of the water, at the departure 10 m, m | 30 |
| Lifting speed (on the main / auxiliary hook), m/min | 1,7 / 3 |
| Crane slewing speed with load 30 T on the hook rpm | 0,11 |
| The speed of movement of the crane by papillon winches, rpm | 5 |
| Draft (during crane operation), m | 1,6 |
| The weight of the superstructure (without rams), T | 215 |
GANZ- one of the oldest brands of floating cranes in the world, represented by full model range, which according to the purpose of floating cranes can be classified as:
Cargo clamshell floating cranes
Load capacity from 5 to 60 tons. Fully revolving, with a straight or articulated boom with a rigid guy. Towed or self-propelled. Fully autonomous or watch-shift version. For transshipment of large volumes of all types of loose / bulk cargo. Due to the combination of increased buoyancy, stability and yaw of the floating crane structure as a whole with a high speed of all basic operations, a high handling capacity is achieved: from 300 to 2000 tons / hour. They can have a river and sea, as well as an ice class of performance. In floating cranes over 5 tons, a 4-rope grab is used. Used as a bottom deepening dredger with the possibility of equipping belt conveyor for unloading the excavated soil. Ability to work in hook mode, which increases the load capacity, but reduces the speed of operations.
Cargo hook floating cranes
Load capacity from 5 to 200 tons. Fully revolving, with a straight or articulated boom with a rigid guy. Towed or self-propelled. Fully autonomous or watch-shift version. For transshipment of piece and heavy loads. With other similarities in characteristics, it differs from cargo clamshell floating cranes by the presence of reduced speeds for performing basic operations required for more accurate work. They can have a river and sea, as well as an ice class of performance.
Assembly and construction floating cranes
Load capacity from 16 to 300 tons. Fully revolving, with a straight or articulated boom with a rigid guy. Towed or self-propelled. Fully autonomous or watch-shift version. They are used in shipbuilding, heavy, energy, transport engineering, construction of bridges and hydraulic structures, as well as work on the development of the sea shelf. Distinguished by work at low speeds: 1-12 meters / minute. They can have a river and sea, as well as an ice class of performance.
Assembly and rescue floating cranes
Carrying capacity from 200 to 500 tons and above. With straight, inclined fixed boom system. Towed or self-propelled. Fully autonomous or watch-shift version. In accordance with the purpose, they can be equipped with a variety of auxiliary equipment. They are used in shipbuilding, heavy, energy, transport engineering, construction of bridges and hydraulic structures, works on the development of the sea shelf and underwater rescue operations. High-speed operating mode: 0.1-5 meters / minute. They can have a river and sea, as well as an ice class of execution. It is possible to equip the boom with a trunk for work with loads less than the rated load capacity in cases where a very large reach of the boom is required.
floating crane– extremely versatile and reliable equipment. They are used for loading and unloading ships, deepening the bottom, building bridges and other water structures.
floating crane almost indispensable in the port for multi-purpose work, due to which the relatively high cost pays off in a short time.
- Floating crane with a lifting capacity of 16 t
- Floating crane with a lifting capacity of 32 tons (Al Furat)
- Floating crane with a lifting capacity of 32 tons (Hafez)
- Floating crane with a lifting capacity of 100 tons (El Mansour)
