Floating cranes of the KPL and KNG modifications belong to the category “river vessels of the technical fleet” and are intended for operation outside port waters, the main function of which is loading and unloading, mining of common minerals (sand, gravel, etc.), dredging and bottom cleaning work in conditions remote from populated areas and other hard-to-reach areas of rivers and lakes.
In some publications, as well as in some internal documents of organizations, in modifications of floating cranes, instead of the abbreviation KPL, the abbreviation KNG is used (The abbreviations KPL and KNG are equivalent and can be indicated depending on the modification of the floating crane). The number after the abbreviation indicates a modification of the floating crane, the technical characteristics of which are determined by the technical documentation of the specific floating crane.
Below are some (but not all) modifications of floating cranes:
- KPL-1 is a full-revolving non-self-propelled floating crane with a lifting capacity of 5 tons and a hook lifting height of 16 m.
- KPL-2 is a full-revolving non-self-propelled floating crane with a lifting capacity of 16 tons and a hook lifting height of 18.3 m.
- KPL-3 is a full-revolving non-self-propelled floating crane with a lifting capacity of 5 tons and a hook lifting height of 24 m.
- KPL-5 is a full-revolving non-self-propelled floating crane with a lifting capacity of 5 tons and a hook lifting height of 18.3 m.
- KPL-5-30 is a full-revolving non-self-propelled floating crane with a lifting capacity of 5 tons and a hook lifting height of 18.3 m.
- KPL-16 is a full-revolving non-self-propelled floating crane with a lifting capacity of 16 tons and a hook lifting height of 22 m.
- KPL-25 is a full-revolving non-self-propelled floating crane with a lifting capacity of 25 tons and a hook lifting height of 16 m.
- KPL-351 is a self-propelled floating crane with a lifting capacity of 350 tons and a hook lifting height of 36 m.
- KNG-19, KNG-20, KNG-22, KNG-25 - full-revolving non-self-propelled floating crane with a lifting capacity of 5 tons with a hook lifting height of 18.3 m.
- KNG-37, KNG-38 - full-revolving non-self-propelled floating crane with a lifting capacity of 5 tons with a hook lifting height of 18.3 m.
- KNG-62 is a full-revolving non-self-propelled floating crane with a lifting capacity of 16 tons and a hook lifting height of 25 m.
- KNG-65 is a full-revolving non-self-propelled floating crane with a lifting capacity of 16 tons and a hook lifting height of 25 m.
- KNG-81, KNG-82 - full-revolving non-self-propelled floating crane with a lifting capacity of 25 tons with a hook lifting height of 25 m.
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An excerpt characterizing the KPL (floating crane)
Having expressed everything that was ordered to him, Balashev said that Emperor Alexander wants peace, but will not begin negotiations except on the condition that... Here Balashev hesitated: he remembered those words that Emperor Alexander did not write in the letter, but which he certainly ordered that Saltykov be inserted into the rescript and which Balashev ordered to hand over to Napoleon. Balashev remembered these words: “until not a single armed enemy remains on Russian land,” but some complex feeling held him back. He could not say these words, although he wanted to do so. He hesitated and said: on the condition that the French troops retreat beyond the Neman.Napoleon noticed Balashev's embarrassment when uttering his last words; his face trembled, his left calf began to tremble rhythmically. Without leaving his place, he began to speak in a voice higher and more hasty than before. During the subsequent speech, Balashev, more than once lowering his eyes, involuntarily observed the trembling of the calf in Napoleon’s left leg, which intensified the more he raised his voice.
“I wish peace no less than Emperor Alexander,” he began. “Isn’t it me who has been doing everything for eighteen months to get it?” I've been waiting eighteen months for an explanation. But in order to start negotiations, what is required of me? - he said, frowning and making an energetic questioning gesture with his small, white and plump hand.
“The retreat of the troops beyond the Neman, sir,” said Balashev.
- For Neman? - Napoleon repeated. - So now you want them to retreat beyond the Neman - only beyond the Neman? – Napoleon repeated, looking directly at Balashev.
Balashev bowed his head respectfully.
Instead of the demand four months ago to retreat from Numberania, now they demanded to retreat only beyond the Neman. Napoleon quickly turned and began to walk around the room.
– You say that they require me to retreat beyond the Neman to begin negotiations; but they demanded of me in exactly the same way two months ago to retreat beyond the Oder and Vistula, and, despite this, you agree to negotiate.
He silently walked from one corner of the room to the other and again stopped opposite Balashev. His face seemed to harden in its stern expression, and his left leg trembled even faster than before. Napoleon knew this trembling of his left calf. “La vibration de mon mollet gauche est un grand signe chez moi,” he said later.
“Such proposals as clearing the Oder and the Vistula can be made to the Prince of Baden, and not to me,” Napoleon almost cried out, completely unexpectedly for himself. – If you had given me St. Petersburg and Moscow, I would not have accepted these conditions. Are you saying I started the war? Who came to the army first? - Emperor Alexander, not me. And you offer me negotiations when I have spent millions, while you are in an alliance with England and when your position is bad - you offer me negotiations! What is the purpose of your alliance with England? What did she give you? - he said hastily, obviously already directing his speech not in order to express the benefits of concluding peace and discussing its possibility, but only in order to prove both his rightness and his strength, and to prove Alexander’s wrongness and mistakes.
The floating crane can be installed on a pontoon or on a ship. A rotating part with a swinging boom is mounted on the crane pontoon. In longitudinal section, the pontoon has a rectangular shape with undercuts at the lower ends of the bow and stern parts. At the ends (in the center plane) of the pontoon of a crane with a lifting capacity of 5 tons (prototype KPL5-30) there are fairleads for installing pile pins.
See slot-v-casino.net slot at.
The metal body of the pontoon is divided into waterproof compartments by longitudinal and transverse bulkheads. The compartments house the engine room, where the main and auxiliary diesel generators are located; drainage, fire, sanitary and other systems; service and residential (for the crew) premises. On the deck of the pontoon there are anchor and mooring mechanisms, a rack for stowing the boom in a stowed position.
Floating reloading cranes are full-rotating, equipped with grab-type lifting mechanisms, and can operate independently of the availability of power sources on shore to reload almost all dry cargo at unequipped berths. The lifting capacity at all boom radii is usually constant, which creates the opportunity, especially when working in grab mode, for continuous loading of ships.
The designs of floating cranes, even with the same lifting capacity and maximum boom radius, may differ in the types of slewing bearings. (on a column or support circle) and a boom system (an articulated boom with a flexible or rigid guy, a straight boom with a leveling pulley). For floating cranes with a lifting capacity of up to 16 tons, the boom is lowered onto the pontoon strut using a lift-out mechanism without disconnecting the boom rods, which reduces the labor intensity of the work and reduces the time spent on laying the boom in the traveling position.
Electricity is supplied to the rotating part mechanisms from a diesel generator located in the engine room of the pontoon, through the internal hole of the central axle and the current collector attached to it. It is also possible to connect the crane to shore power.
The crane is attached to the pier or vessel with mooring ropes wound on the drums of mooring winches or capstans, or with two pile pins lowered into the ground through hawse doors at the end of the pontoon. The piles are lifted from the ground using mooring winches and a pulley system.
Develop a project for a floating crane based on the KPL-5-30 prototype. With technical specifications provided in Table 1.
Technical characteristics of the designed crane
Table 1
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Indicators |
Values |
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Name |
Unit |
Designation |
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Load capacity |
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Speeds: change in boom radius |
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Crane speed |
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Boom Reach: maximum minimum |
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Estimated lift height: above the rail head to the rail head |
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Reloaded cargo |
Container (5 t.) |
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Operating mode |
Tuma-Group sells spare parts and equipment for the KPL 5-30 floating crane. Spare parts for floating cranes KPL 5-30 project R99, R12A, 528, 81040, 1451:
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Rice. 2.6. Floating cranes: A- “Bogatyr”; b– “Bogatyr-3” with an additional boom; V– “Bogatyr-6” with an extended additional boom; Q– permissible load capacity at reach R; N– 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” (Germany) with a lifting capacity from 200 to 1600 tons (Fig. 2.7), “Balder” , Holland) with a lifting capacity from 2000 to 3000 tons (Fig. 2.8).
Oilfield. Crane vessels for the supply of offshore oil fields and the construction of oil and gas field structures on the shelf usually have rotating topsides, 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 towards an increase in the parameters of cranes of this group (load 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 – traveling arrow; 3 – deck winch; 4 – jib tilt winch; 5 – strut; 6 – boom; 7 – jib; 8 – main lift suspension; 9 – auxiliary lift 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 – rotating platform; 3 – boom; I…IV – hook hangers
Rice. 2.9. Crane vessel “Yakub Kazimov”: 1 – pontoon; 2 – traveling arrow; 3 – leveling tackle; 4 – cabin; 5 – rotating part frame
Depending on seaworthiness, taps can be classified as follows:
1) port (for carrying out transshipment work in ports and harbors, enclosed reservoirs and coastal sea (coastal) and river areas, at shipbuilding and ship repair shipyards);
2) seaworthy (for work on the open sea with the possibility of long independent passages).
The domestic crane industry is characterized by the desire to create universal cranes, and the foreign industry - highly specialized cranes.
2.1.2. Construction of floating cranes
Floating cranes consist of a top structure (the crane itself) and a pontoon (a special or crane vessel).
The upper structure of a floating crane, crane vessel, etc.– a lifting structure installed on an open deck designed to carry a lifting device and cargo.
Pontoons, like ship hulls, consist of transverse (frames and deck beams) and longitudinal (keels and keels) elements sheathed in sheet steel.
Frame – a curved transverse beam of the ship's hull, providing strength and stability of the sides and bottom.
Beam– a transverse beam connecting the right and left branches of the frame. The deck is laid on the beams.
Keel- a longitudinal connection installed in the center plane of the vessel at the bottom, extending along its entire length. The keel of large and medium-sized ships (internal vertical) is a sheet installed in the center plane between the double bottom flooring and the bottom plating. To reduce pitching, side keels are installed normal to the outer hull of the vessel. The length of the side keel is up to 2/3 of the length of the vessel.
Kilson– a longitudinal connection on ships without a double bottom, installed along the bottom and connecting the lower parts of the frames for their joint operation.
The shape of the pontoons is a parallelepiped with rounded corners or has ship contours. Pontoons with rectangular corners have a flat bottom and a cut in the stern (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 that of the hulls of ordinary ships. The pontoons of floating cranes are sometimes made unsinkable, i.e. equipped with longitudinal and transverse bulkheads. To increase the stability of a floating crane, i.e. ability to return from a tilted 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 crew and warehouses should be placed inside the pontoon. Only the wheelhouse (ship's control cabin), galley (ship's kitchen) and dining room are brought onto the deck. Inside the pontoon, along its sides, there are tanks (tanks) for diesel fuel and fresh water.
Floating cranes can be self-propelled or non-self-propelled. If the crane is intended to serve several ports or to move long distances, then it must be self-propelled. In this case, pontoons with ship contours are used. Sea-going 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 Värtsilä, Finland, with a lifting capacity of 1600 tons, etc.).
According to the design of the superstructure floating cranes can be classified into fixed-rotary, full-rotary and combined.
Fixed(mast, gantry, with swinging (tilting) booms). Mast cranes (with fixed masts) have a simple design and low cost. Horizontal movement of cargo is carried out when moving the pontoon, so the productivity of such cranes is very low.
Rice. 2.10. Floating crane pontoon diagram
Floating cranes with tilting booms are more suitable for working with heavy weights. With variable reach, their productivity is greater than that of mast-mounted 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 at the bow of the pontoon. The boom is lifted using a rigid rod (hydraulic cylinder, rack or screw device) or using a pulley mechanism (for example, on the Vityaz crane). The boom in the transport position is secured to a special support (Fig. 2.3). To perform this operation, boom and auxiliary winches are used.
A floating gantry crane is a conventional gantry crane mounted on a pontoon. The crane bridge is located along the longitudinal axis of the pontoon, and its only console extends beyond the contours of the pontoon by a distance sometimes called the outer overhang. The outer 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 rotation(universal) cranes come with a rotating platform or a column. Nowadays, tilting boom slewing cranes are widely used. They are the most productive. Their arrows not only tilt, but also rotate around a vertical axis. The lifting capacity of rotary 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 reach of 10.4 m with a lifting height of the main hook (hook) above sea level of 40 m, as well as the offshore transport and installation vessel Ilya Muromets. The latter has a lifting capacity of 2×300 tons at an outer reach of 31 m. The height of the crane vessel with the boom raised is 110 m. These cranes are capable of making sea crossings in storms of 6...7 points and winds of 9 points. Sailing autonomy is 20 days. The speed of the Bogatyr crane is 6 knots, and the Ilya Muromets crane vessel is 9 knots. Both vessels are equipped with a set of mechanisms and devices that provide a high level of mechanization of main and auxiliary processes. In the transport position, the booms of both described vessels are placed on special supports and secured.
Combined. These include, for example, floating gantry cranes, on the bridge of which a rotating crane moves.
The predominant type of boom device for floating cranes is a straight boom with a leveling pulley; Articulated boom devices are used less frequently, but their use is associated with difficulties in stowing in a traveling manner.
To prevent the straight booms of offshore cranes from tipping over during waves, under the influence 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. Magnus cranes have a boom with a load held in place by a rigid strut.
As boom designs developed, a transition was made from lattice and braceless booms to solid-walled (box-shaped, less often tubular) booms in a beam or cable-stayed design. On cranes of recent years, sheet-shaped box booms are more often used. However, lattice booms of some foreign cranes with very large lifting capacities are known (Balder crane, see Fig. 2.8). When modernizing 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 broad unification with the base model.
The main types of slewing bearings for floating cranes are a rotating and fixed column, a multi-roller slewing ring, a slewing ring in the form of a double-row roller bearing. There is a trend towards the use of slewing rings in the form of roller bearings on cranes with a lifting capacity of up to 500 tons. On heavier cranes, multi-roller turntables are still used; work is underway to create segmented roller bearings for such cranes.
Lifting mechanisms used on floating cranes are grab winches with independent drums and differential switches. According to GOST 5534, a reduced speed of landing the grab on the load is provided, amounting to 20...30% of the main speed. It is possible to replace the grab with a hook suspension.
The turning mechanisms (one or two) often have helical-bevel gearboxes with multi-disc torque limiting clutches and an open gear or lantern drive.
The mechanism for changing the reach is sectoral with the 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 reach are known. The designs of mechanisms for changing the reach are presented in section 1 “Gantry cranes”.
Floating reloading grab cranes in river and sea ports are used very intensively. For lifting mechanisms, the PV values reach 75...80%, for turning mechanisms - 75%, for mechanisms for changing reach - 50%, the number of starts per hour - 600.
2.1.3. Calculation features
Pontoon geometry. 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 center plane, runs along the pontoon and divides it into equal parts. The intersection line 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 midship frame plane, or midship plane. The intersection line of the main and midship planes is taken as the axis Y, and the line of intersection of the midship and center planes - behind the axis Z.
The plane parallel to the midsection plane and passing through the axis of rotation of the rotary valve is called medial. The lines of intersection of the surface of the pontoon hull with planes parallel to the midsection plane are called frames (the same name is given to the transverse elements of the vessel that form the frame of its hull). The lines of intersection of the surface of the pontoon body with planes parallel to the main plane are called waterlines. The mark of the water surface on the pontoon body has the same name.
Since a pontoon located on the water can be inclined, the resulting waterline is called active. The plane of the current waterline, non-parallel to the planes of the other waterlines, divides the pontoon into two parts: surface and underwater. The waterline corresponding to the position of the crane on the water 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 tilt of the ship to the bow or stern is called trim, and the tilt of the ship to starboard or port is called heel. Corner ψ (see Fig. 2.10) between the effective and main waterlines in the center plane is called the trim angle, and the angle θ between the same lines in the midsection plane - the roll angle. When trimmed to the bow and when heeling towards the boom, the angles ψ And θ are considered positive.
Length L pontoons are 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 effective waterline is called draft T pontoon, which has different meanings at the bow of the pontoon T H and at the stern T K. Difference of values T H – T K called 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 calculations a so-called theoretical drawing is drawn up, which 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 the underwater part of the pontoon is called volumetric displacement. The center of gravity of this volume is called the center of magnitude and is designated CV. Mass of water in volume V called mass displacement D.
Stability of floating cranes. Stability is the ability of a ship to return to a position of equilibrium after the forces causing it to tilt cease.
Features of calculating the stability of floating cranes largely come down to taking into account the influence of roll and trim. The crane without a load should have a trim 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 tilt towards the counterweight, and with a load - towards the load. The change in reach due to roll or trim can amount to several meters. The design reach is taken to be the reach that the crane has when the pontoon is in a horizontal position.
For a crane with a load, the rotating part of the crane with a counterweight creates a moment that partially balances the load moment and is called balancing (see Fig. 2.10): M У = G K y K , Where G K- weight of the superstructure; yK- 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 defined as the sum of the moments from the superstructure weights and counterweights.
Load moment M G = GR,Where G- weight of cargo with hook suspension; R- arrow departure. The ratio of the balancing moment to the load moment is called the balancing coefficient φ = M U / M G.
To determine the heeling and trim moments, consider Fig. 2.11, which shows the pontoon and boom in plan. Weight of the rotating part of the crane with load G K attached at a distance e from the axis O 1 boom rotation. Action of weight G K on the shoulder e can be replaced by the action of vertical force G K at the point O 1 and the moment G K e in the plane of the arrow. Pontoon weight with ballast G 0 applied at point O2. In addition, the crane is subject to a vertical moment from the wind load, which has components relative to the corresponding axes M VX And M ВY. Then the heeling moment is determined by the dependence of the form M K = M X = G K e cos φ + M BX, and the trimming moment M D = M U = G K e sin φ + M B Y.
To determine the restoring moment, consider Fig. 2.12, which shows a cross-section of the pontoon along the midsection plane in positions before and after the application of the heeling moment. The center of gravity of the pontoon crane is indicated DH. A crane at rest is subject to vertical forces having a resultant N, and buoyant force D = Vρg, Where V- displaced volume; ρ - density of water; g- acceleration of gravity. According to Archimedes' law, D=N.
In a state of balance of power N And D act along one vertical, passing through the center of gravity and the center of magnitude and called the axis of swimming. In this case, the roll angle may have some significance θ (see Fig. 2.10).
Rice. 2.11. Scheme for determining heeling and trim moments
Rice. 2.12. Diagram of the pontoon position before ( A) and after ( b) application of heeling moment
Let us 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 the value shifts. By changing forces D And G in comparison with 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 an inclined position the crane will be applied at the point CV(Fig. 2.12, b). In this case, a restoring moment of force will occur 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.
A point is called a metacenter F intersection of the swimming axis with the line of action of the force D, and the metacentric radius is the distance from the metacenter F to the center of the value.
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 are called static stability coefficients.
Let us determine the metacentric radii and . From the theory of the ship the following is known:
1) at small roll angles θ and trim ψ metacenter position F unchanged, and the center of the quantity moves along a circular arc described around the metacenter;
2) metacentric radius R=J/V, Where J- moment of inertia of the area limited by the waterline relative to the corresponding axis around which the crane tilts.
For a crane at rest, the area limited by the waterline is equal to B.L..
For a rectangular pontoon (without taking into account contours and bevels), moments of inertia about the main axes J X = 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 are ; 
.
Thus, the angles of roll and trim, depending on the heeling and trim moments, are determined from the expressions
; 
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Rice. 2.13. Floating crane stability diagrams: A– static M VK(q); b – dynamic A B(q)
For slewing cranes with an oscillating boom, these angles are variable both in terms of reach and 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 righting moment M VK depending on the angle θ changes according to the static stability diagram (Fig. 2.13). With a gradual increase in heeling moment to a value equal to the maximum value of the righting moment M VK max on the diagram, the roll angle reaches θ M , and the crane will be unstable, since any accidental tilting in the direction of the roll will lead to capsizing. Application of heeling moments M θ ³ M VC max is not allowed. Dot TO(sunset diagram) characterizes the maximum roll angle θ P , when exceeded M VK< 0 and the crane overturns. The static stability diagram is included in the mandatory crane documentation; its construction according to a drawing of a pontoon or using approximate formulas is given in the work.
In case of sudden (or in a time less than half-period of natural oscillations) application of a dynamic moment to an unheeled pontoon M D(see Fig. 2.13, A), which subsequently remains constant, in the initial period of roll M D > M VK and the ship will roll with acceleration, accumulating kinetic energy. Having reached the static roll angle q(dot IN), the ship will heel further up to the dynamic heel angle q D, when the reserve of kinetic energy is spent to overcome the work of the restoring moment and resistance forces (point WITH, corresponding to equality of areas OAV And SVE). 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 coefficient ( x" 0.7); in the presence of an initial roll angle ± q 0 dynamic roll angle q D = ± q 0+ 2q. Overturning dynamic moment M D.OPR and tipping angle q D.OPR determined by finding a straight line AE, cutting off equal areas on the static stability diagram OAV And VME(Fig. 2.13, b).
The dynamic stability diagram (see Fig. 2.13) is a graph of the work of the restoring moment A B= D from the roll angle ( l q- righting moment arm 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 dynamic stability arm. 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 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 roll angle q D (A) or rollover angle during dynamic roll q D.OPR (b).
Dynamic roll (or trim) occurs when the load is lifted with a jerk or when the load breaks. In Fig. 2.14 shows the position of the water mirror relative to the pontoon for a crane without a load (equilibrium position 1 at bank angle q 0) and with a load in a static roll (position 2 at bank angle q). For normal operation of the crane, it is desirable to have equality in the absolute values of the roll angles for a loaded and empty crane. If the load breaks, the crane will oscillate relative to its equilibrium position 1 with amplitude Δ q(see Fig. 2.14), reaching the position 3 at dynamic roll 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= q 0+ (0.5 – 0.7) Δ q.
Rice. 2.14. Pontoon diagram for determining dynamic roll
Determination of the overturning moment and the angle of dynamic roll in operating condition in the event of a cargo breakage according to the dynamic stability diagram, as well as checking the stability of the crane during transition, hauling, and in non-operating condition; The determination of the overturning moment in the traveling state and the maximum righting moment in the non-operating state are discussed in detail in the work.
Loads on the rotation mechanism and changes in reach. In Fig. 2.15, A shown transversely (in the plane Y) and longitudinal (in the plane X) sections of the pontoon after a roll at an angle q and trim by angle ψ .
Weight G K the rotating part of the crane with a load has components S And S X, acting in the plane of rotation and determined by dependencies of the form S Y = G K sin q And S X = 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 component of the trimming moment М ψ = G К a – G 0 b = 0(balanced pontoon), then the maximum M φ achieved at φ = 45 o.
Powers S X And S have components acting in the plane of swing of the boom and perpendicular to it. The components acting perpendicular to the swing plane of the boom create a moment that loads the rotation mechanism, the expression for which was obtained above. Total force T component forces S X And S in the boom swing plane is determined by an expression of the form T= S X sin φ + S Y cos φ = G K ( sin q sin φ – sin ψ cos φ).
This force acts in the plane of swing of the boom and is directed along the pontoon. In Fig. 2.15, b weight decomposition shown G K to strength R, perpendicular to the main plane of the pontoon and taken into account in the calculations of the mechanism for changing the reach, and on the force T, parallel to the longitudinal axis of the pontoon and creating additional load caused by roll and trim. Thus, in the center of gravity of each unit of the rotating part of the crane (boom, trunk, etc.) the weight G i power arises T i caused by roll and trim. Additional point M, loading the mechanism for changing the offset, is determined by the formula .
Loads from inertia forces, acting on the crane during transverse and longitudinal pitching of the vessel, are presented in detail in the works.
Unsinkability– the ability of the ship to maintain the minimum required buoyancy and stability after flooding of one or more hull compartments. The calculation of unsinkability is presented in detail in the work.
1. Introduction
2. Initial data for design
3. Crane performance and operating mode of its mechanisms
Lifting mechanism
Boom system and reach change mechanism
Slewing ring and turning mechanism
Crane stability
Control of crane mechanisms
Conclusion
Literatures
1. INTRODUCTION
The floating crane can be installed on a pontoon or on a ship. A rotating part with a swinging boom is mounted on the crane pontoon. In longitudinal section, the pontoon has a rectangular shape with undercuts at the lower ends of the bow and stern parts. At the ends (in the center plane) of the pontoon of a crane with a lifting capacity of 5 tons (prototype KPL5-30) there are fairleads for installing pile pins.
The metal body of the pontoon is divided into waterproof compartments by longitudinal and transverse bulkheads. The compartments house the engine room, where the main and auxiliary diesel generators are located; drainage, fire, sanitary and other systems; service and residential (for the crew) premises. On the deck of the pontoon there are anchor and mooring mechanisms, a rack for stowing the boom in a stowed position.
Floating reloading cranes are full-rotating, equipped with grab-type lifting mechanisms, and can operate independently of the availability of power sources on shore to reload almost all dry cargo at unequipped berths. The lifting capacity at all boom radii is usually constant, which creates the opportunity, especially when working in grab mode, for continuous loading of ships.
The designs of floating cranes, even with the same lifting capacity and maximum boom radius, may differ in the types of slewing bearings. (on a column or support circle) and a boom system (an articulated boom with a flexible or rigid guy, a straight boom with a leveling pulley). For floating cranes with a lifting capacity of up to 16 tons, the boom is lowered onto the pontoon strut using a lift-out mechanism without disconnecting the boom rods, which reduces the labor intensity of the work and reduces the time spent on laying the boom in the traveling position.
Electric power is supplied to the rotating part mechanisms from a diesel generator located in the engine room of the pontoon, through the internal hole of the central axle and the current collector attached to it. It is also possible to connect the crane to shore power.
The crane is attached to the pier or vessel with mooring ropes wound on the drums of mooring winches or capstans, or with two pile pins lowered into the ground through hawse doors at the end of the pontoon. The piles are lifted from the ground using mooring winches and a pulley system.
2. INITIAL DATA FOR DESIGN
Develop a project for a floating crane based on the KPL-5-30 prototype. With technical specifications provided in Table 1.
Technical characteristics of the designed crane
Table 1
Speeds: lifting boom radius change m/min m/min
Estimated lifting height: above rail head to rail head m m
. PERFORMANCE OF THE CRANE AND OPERATING MODE OF ITS MECHANISMS
The cargo transhipment technology for the wagon-ship operation option is schematically shown in Fig. 1.
Rice. 1 Diagram of the warehouse-ship crane operation variant. hp - lifting height of the load, hp=7 m; hop - height of lowering the load, hop=12 m; - angle of rotation of the crane = 180°; R1 - minimum boom radius, R1=8 m; R2 - maximum boom radius, R2=27 m.
Productivity is nothing more than the mass of cargo handled in 1 hour of work.
where is the mass of the load;
Number of cycles per hour.
cargo weight:
Let's determine the number of cycles per hour:
where is a coefficient taking into account the combination of cycle operations, assumed to be 0.8;
Time for securing the load:
Time to lift the load to a height:
With
Time for turning the crane with a load and back;
Boom extension change time;
Load lowering time:
Time to unsling from load:
Gripper installation time:
Average duration of activation of crane mechanisms:
lifting mechanism
rotation mechanism
departure mechanism
4. LIFTING MECHANISM
The load lifting mechanism is designed for lifting, holding, adjusting, lowering loads, as well as activating grabs
The lifting mechanism of a hook crane consists of a hook, cargo ropes, guide blocks, and identical single-drum winches. Each winch is equipped with an electric motor, a clutch, a double-block brake, a gearbox, and a coupling for connecting the gearbox to the drum. One of the winches is called closing, the other - supporting. The ropes wound onto the drums of these winches are named accordingly - closing and supporting.
The hook crane has 2 lifting mechanisms. A prerequisite for the design of the lifting mechanism is a speed control device. The lifting mechanism is equipped with a set of devices that ensure safe operation, such as: load limiter (LOL), limit switches for lifting height and lowering depth.
Rope calculation
The calculation of the lifting mechanism begins with the selection of a cargo rope.
The steel rope of the cargo winch is selected according to GOST, taking into account the breaking force
where is the maximum force in the rope branch;
Rope utilization rate;
For cranes with clamshell operation.
Let us determine the maximum force in the rope branch:
where is the acceleration of free fall;
Number of ropes leaving the end blocks;
Taking into account the found breaking force, a double lay steel rope of type LK-R 6x19 wires with one organic core with a diameter of 24 mm, GOST 2688-80 is suitable for the designed crane.
Block calculation
The blocks are calculated and selected taking into account the ropes passing through them.
According to GOST rules, the diameter of the block is determined:
Let us depict the rope block according to the calculations made for the designed crane in Fig. 2.
Rice. 2 Rope block
Drum calculation
1. - cutting step;
Drum groove depth:
Groove radius:
Rice. 3 Groove profile for rope with single-layer winding
Drum diameter:
Drum section thickness:
Drum length:
where is the length of the drum cutting;
Determine the length of the uncut part of the drum
A- length of the uncut part of the drum.
Total number of threading turns;
where are the working turns;
H1=23 m=23000 mm;
H2=15 m=15000 mm;
Spare coils;
Fastening threads;
Determine the length of the drum cutting
Determine the length of the drum
Fig.5 Fastening the rope to the drum with pads
Calculation of the electric motor of the lifting mechanism
Let's determine the required power of the crane:
where is the overall efficiency of the mechanism;
Since the designed crane has a hook mode of operation, two electric motors with the following power are used:
Guided by the above calculations, we select an engine of type MTN 711-10 with a power N 80 kW and rotation speed 580 rpm.
Gearbox calculation
To select a gearbox, we need to know the gear ratio:
where is the drum rotation frequency;
Taking into account the found gear ratio, we select the RM-850 gearbox, which has a high-speed shaft rotation speed of 600 rpm, power at duty cycle = 40% - 69 kW, at duty cycle = 100% - 27.9 kW.
Brake calculation
Calculation and selection of a brake begins with finding the value of the braking torque:
where is the braking coefficient;
Torque;
where is the number of winches;
Taking into account the braking torque, we select a shoe brake driven by an electro-hydraulic pusher type TKG-400M with a brake pulley diameter of 400 mm and a braking torque of 1500 Nm.
5 BOOM SYSTEM AND MECHANISM FOR CHANGING BOOM REACH
The mechanism for changing the boom radius with a boom device is designed to change the radius of the serviced area. With variable reach, the distance from the load to the center of rotation of the crane changes and the crane services the area between two circles with radii equal to the maximum (Rmax=30m) and minimum (Rmin=8 m) boom reach.
The crane we are designing uses an articulated boom system, consisting of a boom, a trunk and a guy. The guy is flexible, in the form of a rope. The geometric dimensions of the boom, trunk and guy rope must be such as to ensure the ability to move the load to a given height and a given maximum and minimum boom reach. The flexible guy is hinged on the trunk with a constant shoulder, i.e. a constant distance from this hinge to the point of connection of the boom with the trunk. The trunk, hingedly connected to the boom, can move relative to the boom in its plane. In order to reduce power consumption by the mechanism for changing the reach, the boom systems are balanced by a movable counterweight with variable reach.
Mechanism for changing boom extension on the designed crane it is sector-crank.
In a sector-crank mechanism, the gear sector is driven by a gear. The sector, rigidly attached to the counterweight rocker arm, has a common axis of rotation with the rocker arm, supported by supports. When the gear rotates, the gear sector together with the rocker arm rotates, and the force of the boom rod, pivotally connected to the rocker arm and the boom, causes the boom to swing. The kinematic diagram of the mechanism for changing the boom reach is shown in Fig. 5.
Kinematic diagram fig.
6 ROTARY DEVICE AND ROTARY MECHANISM
The slewing bearing and rotation mechanism are used in all load-lifting cranes, which provide for the rotation of part of their structure around a vertical axis. All of them belong to full-rotary and part-rotary cranes.
There are two main types of full-rotation devices: on a platform (for our crane), on a column.
In a slewing crane, the turning part rests on wheels or rollers that move along a circular rail (rail ring) attached to a support drum. The turning mechanism on the turntable consists of an electric motor, an elastic coupling with a brake pulley, a double-block brake, and a gearbox with a vertical shaft, at the end of which a spur gear is mounted on a key. When rotating, this gear is pushed off from a stationary gear (rigidly attached to the support drum) and runs around it, providing the turntable with rotation around a vertical axis at a certain frequency.
To protect shafts and gears from overload, a friction gear is installed in the gearbox, consisting of driving friction disks, driven lower and upper friction pressure disks, and a spiral/pressure spring.
The following devices are used in the rotating support and rotation mechanism for safe operation:
blocking the brake of the rotation mechanism;
built-in limit torque clutch, which slips in cases of sudden start-up or sudden braking of the rotation mechanism, as well as in case of jamming of the rotating part.
The rotation mechanism has to overcome resistance:
friction forces (in the mechanism itself);
inertia forces (during acceleration, braking and when changing speed in general);
wind loads.
Calculation of the load acting on the trunk guy wire.
7. CRANE STABILITY
Stability- this is the ability of a pontoon with a rotating part to return to its original position after the cessation of external forces causing its inclination.
Due to the imbalance of the boom system, when taking a load onto a hook or into a grab, the center of gravity of the rotating part almost always does not coincide with the vertical axis, so a heeling moment appears, tilting the pontoon at a certain angle. Under the influence of a heeling moment, the pontoon with the rotating part comes out of equilibrium. The shape of the underwater part of the pontoon will change when it tilts, and the center of gravity of the part of the pontoon immersed in water will move to another point, resulting in a moment that counteracts the tilt. This moment is called restorative. After the heeling moment ceases, the pontoon with the rotating part must return to its original position under the influence of the righting moment.
When creating and operating river floating cranes, the concept of static stability is used. The measure of static stability is the restoring moment. The permissible value of the static heel angle according to the River Register Rules should not exceed 3030//. The dynamic heel angle that occurs when the cargo is broken or heavy winds should be no more than 60.
8 CONTROL OF CRANE MECHANISMS
The control devices are designed and installed in such a way that the control is convenient and does not make it difficult to monitor the load-handling member and the load.
The direction of the handles and levers corresponds to the direction of movement of the mechanisms. Symbols of the directions of caused movements must be indicated on the devices and will be preserved during their service life. Individual positions of the handles are fixed; the clamping force in the zero position is greater than in any other position.
Push-button devices intended for reversing starting of the mechanism have an electrical interlock that prevents the supply of voltage to the reversing devices when both buttons are pressed simultaneously.
The crane control cabins comply with the State Standard Rules and other regulatory documents.
The control cabin and control panel are located so that the crane operator can monitor the load-handling device and the load during the full operating cycle of the crane. The control cabin is located in such a way that during normal operation of the crane with a minimum reach of the boom, the possibility of a load or load-handling member hitting the cabin is eliminated.
The crane cabin is equipped with: an indicator for changing the boom radius, an anemometer, signaling devices and provides free visibility and access to them.
The cabin glazing is designed in such a way that it is possible to clean the glass both from the inside and outside. The lower windows on which the crane operator can stand with his feet are protected by gratings capable of supporting his weight. Sun shields are installed in the cabin.
The floor in the cabin has a flooring made of non-metallic materials that prevent slipping and is covered with a dielectric mat.
The door to enter the cabin is sliding and equipped with a lock on the inside. The area in front of the cabin entrance is fenced. The crane is equipped with a device for locking the door from the outside when the crane operator leaves the crane. Entry into the cabin through the hatch is not permitted.
The cabin is equipped with a stationary seat for the crane operator, arranged so that you can operate the equipment while sitting and monitor the load. The seat is adjustable in height and in the horizontal plane for ease of operation and maintenance of control devices.
The crane cabin is designed and equipped in such a way that it ensures proper temperature conditions and air exchange in accordance with regulatory documents.
9.CONCLUSION
The design of the crane as a lifting and transport machine and a floating structure must provide: the necessary reserves of buoyancy, stability, unsinkability and strength of the pontoon hull; reduction of yaw rate during crane operation; high-performance reliable operation when reloading bulk and piece cargo; autonomy of operation for a certain time at various berths, regardless of shore sources of supply of electricity, fuel, lubricant, etc.; minimal manual labor costs; safety during maintenance, repair and reloading operations; ease of assembly of units during manufacture, installation and dismantling with the least amount of adjustment work; convenient access to places for lubrication and inspection of critical components; remote control of the rotating part mechanisms, main and auxiliary power plants or their automation; the smallest weight of the pontoon with a rotating part (so that the crane can be lifted onto the slip for inspection and repair of the rotating part of the hull); the ability to tow under bridges, power lines and through locks for classes I and III inland waterways; safety of vehicles and cargo during transshipment operations.
You also need to remember about the living and working conditions of the floating crane crew; When designing a floating crane, it is necessary to take into account that crew members work and rest on board the floating crane for a long time. Therefore, living conditions on board require a good ventilation system made with the latest technology; water supply system; heating system; for accommodation - spacious and comfortable cabins; for active recreation - equipped gym; equipped premises for cooking and eating.
Currently, great attention is paid to the environmental problem; therefore, I believe that the floating crane should be equipped with containers for collecting subsoil water, waste water, and household waste; because the crane can operate autonomously for a long time in remote areas of the river basin.
When designing a crane, it is necessary to equip it with fire safety control systems and modern fire extinguishing systems.
10. LIST OF REFERENCES USED
floating crane mechanism stability
1. V.V. Avvakumov Transport hubs and terminals. Tutorial. - Omsk. NGAVT, 2001 - 90 p.
2. V.D. Burenok Guidelines for completing a course project in the discipline Port hoisting and transport machines. - Novosibirsk. NIIVT, 1985 - 31 p.
V.D. Burenok Guidelines for performing test work in the discipline Port handling equipment “Calculation of a grab-conveyor loader.” - Novosibirsk. NIIVT, 1992 - 32 p.
I.A. Ivanov Guidelines for performing laboratory work in the discipline “Transport terminals and handling equipment.” - Novosibirsk. NGAVT, 2001 - 22 p.
N.P. Garanin Port lifting and transport equipment. Textbook for water science institutes. trasp. - M.: Transport, 1985 - 311 p.
Z.P.Sherle, G.G.Karakulin, A.P. Kazakov, Yu.I. Vasin Handbook of a river port operator. - M.: Transport, 1967 - 416 p.
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