Lifting equipment is actively used not only in the land areas of our planet, but also in water open spaces, because the construction of various hydraulic structures without fail requires special cranes, the design of which, in turn, is fully adapted for work in the water sector. Floating cranes - machines that can solve the above problems. Therefore, we consider these units in more detail.
Appointment
Floating cranes were initially focused on the construction of various bridges, ports, towers in the waters of the seas, rivers and oceans. Their carrying capacity can be from 10 to 100 tons. The unique design of these machines fully complies with the main requirements put forward by the Maritime Register, namely: optimal strength, ideal buoyancy and stability.
Varieties
Structurally floating cranes are:
- Not rotatable . These units have fixed masts, in connection with which the movement of cargo in the horizontal plane occurs due to the movement of the pontoon. This feature ultimately affects the performance of the unit - it is very small. True, the cost of these cranes is also low.
- Gantry.
- Equipped with a tilting boom . It is these lifting machines that are the most optimal for working with large loads. Due to the variable reach of the boom, the crane's performance is quite high in comparison with mast counterparts. In addition, cranes with a swinging mast have a low intrinsic value, colossal lifting capacity and a relatively simple design. Their arrow is presented in the form of a pair of racks, which converge at the top at an acute angle, and are pivotally mounted on the pontoon itself. In the transport position, the boom is fixed on a support specially created for this. The boom is raised / lowered using a hydraulic cylinder, a gear rack, a screw device, and a chain hoist system.
- Rotatable. The highest performing floating cranes. The boom of any such unit is capable of not only tilting, but also rotating around its vertical axis. At the same time, the carrying capacity of these machines can be several hundred tons. Also, cranes can have a rotary column or a rotary platform.
- Combined.
Intended classification
Any floating crane can be used either for loading and unloading operations in the port, or for installation work. Of course, practically the main role will be played by the capacity indicator of the unit. As for the degree of maneuverability, all of these cranes can be both self-propelled (for example, the ASPTR-1 floating crane) and non-self-propelled. If it is planned that the crane will have to serve several ports at once or move over impressive distances, then in this case it will certainly be self-propelled (use pontoons with ship-type contours).
Universal machine
A floating KPL crane was manufactured at the Kirov plant in St. Petersburg. The unit had two versions: hook and clamshell.
The machine is made fully rotary. The boom has a lattice design and is connected to the movable counterweight of the balancing system using a hinge assembly. At the time of change of the boom reach, the jib moves in the opposite direction with respect to it, which ensures that the load is at the required height.
Design Features
The KPL-5 floating crane has alternating current electric motors operating at a voltage of 220-380 V and having a power of 267 kW. The current is generated by a diesel generator set located on the shore or in the pontoon body. Type of crane control - electromechanical.
The rotating part of the crane with the boom and the whole complex of rotary and other hoisting mechanisms is located on the rollers, which, in turn, move along the rim mounted on the beam cage.
The crane itself is not self-propelled, and therefore its movement occurs with the help of winches.
To bring the crane into transport position, lower the boom and dismantle the mechanism for changing its departure. As a result, the height of the crane will decrease to 10 meters.
The crane is designed and serves to carry out loading and unloading operations, which is why it has high speeds of operations. The crane does not perform installation work because of the low load capacity, but it can be used as an auxiliary near a concrete plant for transshipment of cement from a smooth surface, unloading of timber and other goods. If the mounted elements are lightweight, then the use of a crane is also allowed for construction.
Veteran
The ASPTR-1 self-propelled floating crane was built at the Krasnaya Kuznitsa shipyard located in the city of Arkhangelsk on June 30, 1962. The vessel had a displacement of one thousand tons, a carrying capacity of 15 tons, a length of 38 meters, a width of 13 meters, a height of 3.2 meters. This vehicle was assigned in the port of Novorossiysk and belonged to the State Marine Emergency and Rescue Coordination Service of the Russian Federation. Unfortunately, on October 12, 2016, during the laying of the underwater trunk pipeline, the crane failed, as a result of which it had to be towed to the shore. However, due to extremely adverse weather conditions, the car sank. On board were eight people.