Treatment method for the derailment of large rail cranes

derailment of large rail cranes

The derailment of large rail-mounted container cranes (hereinafter referred to as rail cranes, mainly including quay cranes, gantry cranes, and rail-type field bridges) refers to the phenomenon that the wheels of the cart are detached from the rails during the running of the rail crane. Generally, the wheel rim falls off the rail surface. Or the top of the wheel rim is higher than the rail surface. The derailment of the rail crane will easily cause the metal structure of the crane to be distorted and deformed, resulting in the crane tilting or even overturning accidents, which will bring significant economic losses to the container terminal.

1 Classification of derailment of large rail cranes

Rail cranes generally do not turn to derail when walking on a straight crane rail track. The derailment is mainly divided into climbing derailment, sliding derailment, jumping derailment, and external force derailment.

(1) There is a foreign object with a high hardness on the track of the derailed cart. When the wheel of the cart climbs on a foreign object, the bottom of the wheel rim is higher than the rail surface. Press on the rail surface or leave the track.

(2) Sliding on and off the rails Due to problems with the coordination of the large and small balance beams of the cart or the pin shaft of the trolley, or the height difference between the sea and landside tracks, the center of gravity of the track crane changes, and the traveling of the cart shifts, resulting in interference between the rim of the cart and the track After rail gnawing, abnormal wear of the wheel rim and track accumulates to a certain extent, the wheel rim slides directly onto the track tread.

(3) Jumping on and derailing when the cart is running at full speed, the one-side clamp or brake is suddenly released and fails, and the one-side wheel is clamped. At this time, the movement trend of the track crane changes from linear motion to rotary motion. Under the action of the vehicle, the wheels of the cart are derailed after jumping onto the track.

(4) Derailment due to external force The derailment of the cart occurs due to a large lateral force impact when traveling, or the wheels of the cart are derailed from the track under the action of strong external forces such as typhoons and strong gusts of wind.

2 Causes of derailment of large rail cranes

(1) Internal factors refer to mechanical reasons. The wheel derailment under the action of internal factors must meet two mechanical conditions: the lateral force on the wheel increases; the vertical force on the wheel decreases.

(2) External factors are the external causes that make the wheels reach the mechanical conditions of derailment, mainly including the metal structure of the cart changes, resulting in the misalignment of the wheels and the track; The foreign matter on the track was not cleaned up in time, and the rail sweeper of the crane failed; the cart trolley was hit by external force; corresponding anti-typhoon measures were not taken when the typhoon passed through; the track crane was hit by a gust of wind during operation.

3 Site confirmation of large-scale rail crane derailment accident

When the rail crane derails, the on-site operators should report it to the technical department immediately, and the technicians will confirm and comprehensively evaluate the derailment situation on site.

(1) Confirm whether the rail crane has the possibility of overturning. If the track crane is about to overturn, the on-site operators should be evacuated as soon as possible, and the nearby track cranes should be removed as much as possible; Depression measures to prevent further tilting or overturning of the equipment; if there is no overturning tendency after the rail crane is derailed, or corresponding measures have been taken to prevent the rail crane from overturning, corresponding personnel and tools should be organized in time to reset the rail crane as soon as possible.

(2) Confirm whether the site has the conditions for derailment recovery. Confirm the damage of the wharf ground and cart tracks, and arrange repairs as soon as possible if the damage is serious. Pay close attention to the weather conditions. If the wind is still strong at that time or there will still be typhoons landing later, you should take lashing and reinforcement measures, and derailment recovery should be carried out after the weather improves.

4 Emergency treatment for the derailment of large rail cranes

4.1 Technical staff preparation

Convene relevant technical personnel to hold a pre-work meeting, implement the responsibilities of the on-site person in charge and safety commissioner, construction personnel, and construction units, and formulate construction plans, schedules, and emergency treatment plans. Personnel participating in the project must fully understand their responsibilities and prepare relevant tools in advance.

4.2 Tool preparation

Prepare corresponding tools according to the derailment conditions of large-scale rail cranes on site (equipment self-weight, offset distance, etc.). Taking the shore bridge as an example, the following tools are mainly involved: (1) Hoisting and jacking tools, including one truck crane and one forklift, chain block, chain block, wire rope, shackle, 6 hydraulic trolleys, 2 sets of Jacks and hydraulic pump stations, as well as several steel beams, jacking tire racks, pads; (2) carbon planer welding tools, including several electric welders, carbon planers, oxygen, and acetylene, cutting tools, grinding tools, and prepare corresponding quantities E5015 welding rods, welding rod insulation barrels, carbon rods and paints, etc.; (3) guiding aids, including several 20# and 40# I-beams, 20# channel steel, lifting lugs, and thick steel plates, adjusting wedges Blocks are prepared according to site conditions.

4.3 Security matters

Before the construction, the technical personnel shall be notified of the pre-work safety, and the whole construction process shall be carried out in accordance with the relevant safety regulations of the wharf. The main precautions include:

(1) Do a good job in the safety enclosure of the construction site;

(2) Do a good job of power-off measures for equipment-related institutions, and put up signs prohibiting closing;

(3) Hot work must be carried out in strict accordance with national standard construction specifications, for example, the distance between oxygen and acetylene should be appropriate, the welding wire must be checked before welding, and fire extinguishing equipment must be equipped on the welding site;

(4) Apply for hot work permits in advance, hot work personnel must have relevant qualifications and report to the security department;

(5) When carrying out jacking and hoisting operations, attention should be paid to the position of personnel;

(6) Construction workers must take labor protection measures.

4.4 Construction method

Taking the shore bridge as an example, the track on the sea and landside tends to derail towards the landside. The shore bridge can be re-filled into the track with the help of temporary trolleys, track beams, jacking tire racks, jacks, and other tools. The specific treatment methods are as follows.

4.4.1 Landside treatment

(1) Remove the temporary binding and fixing devices and the peripheral parts on the land side that hinder the lifting of the trolley and the displacement of the quay bridge, such as rail clamps and guardrails of the cart.

(2) If the metal structure of the cart has deformed steel plates that affect the movement of the quay bridge into the track, it can be cut off depending on the situation, and the lower beam and walking mechanism are moved to the bottom of the column and kept perpendicular to it. Beams and running gear.

(3) After the steel plate is cut off, the I-beam and the steel plate are welded together between the lower column and the lower beam, and temporarily fixed.

(4) Lay the jacking tire frame and steel girder under the land side of the connecting beam, requiring the upper steel beam to be close to the bulkhead at the end of the connecting beam; Stick it firmly and weld it; weld the column and the tire frame together with No. 20 I-beam at the first bulkhead above the flange of the lower column, and strengthen it with channel steel, and weld the reinforcing plate in the connection beam.

(5) Place the jacking trolley on the track beam, move the trolley to the bottom of the tire frame, and place the steel beam above the trolley; then, weld stoppers on the front and rear track beams of the trolley to prevent the trolley from moving.

(6) The trolley jacks on both sides are synchronously and slowly lifted to withstand the tire frame so that the tire frame and the rigid beam of the trolley are firmly attached. During the slow lifting process, pay attention to observing the lifting and tilting of the trolley to ensure that the traveling mechanism can fall off the track.

(7) Weld the auxiliary lifting lug according to the site conditions as the bearing point for the traveling mechanism to be pulled by the hand chain hoist.

4.4.2 Seaside treatment

(1) Remove temporary lashing and fixing devices and components on the periphery of the seaside that hinders the lifting of the trolley and the displacement of the quay bridge, such as rail clamps, guardrails for carts, etc.

(3) After the steel plate is cut off, the I-beam and the steel plate are welded together between the lower column and the lower beam, and temporarily fixed.

(4) Relatively fix small balance beams, trolleys, etc., to prevent each part of the cart from finding its own balance point due to different self-weights after the quay bridge is jacked up.

(5) Place the rigid beam and the track beam under the large balance beam on the seaside, put the jacking trolley on the track beam and move it under the large balance beam, and weld the stoppers to prevent the trolley wheels from moving, pay attention to the sea side of the track beam Place pads under the direction to cushion.

4.4.3 Move into orbit

(1) Place the forward horizontal displacement jack and the jacking backer on the land side of the seaside trolley, and weld them on the track beam.

(2) Do a good job in the preparations before the displacement of the quay crane and the cleaning of the displacement site, welding the displacement termination stopper, and cutting off the forward welding stopper of the trolley.

(3) Jack up the sea side of the trolley so that the wheels are off the ground, place cushion blocks on the jacking trolley, and operate the jack synchronously to move the quay bridge to the sea side. During the forward movement of the quay bridge, pay attention to the protection of the land side direction and the relative position of the land side traveling mechanism and the track until the wheels of the cart on both sides of the sea and land are directly above the track. Location.

(4) Operate the jack to drop the trolleys on both sides of the sea and land, remove the steel beams, track beams and jacking trolleys on the ground, and remove the tire frame on the land side as appropriate.

(5) Tow the quay bridge to the windproof fastening position, fasten the windproof cable, block the direction of the wheels with wedges to prevent the wheels from moving, and clean up the site.

(6) After the quay bridge is effectively fixed, inspect the girders and their hinge points of the gantry and restore them.

5 Preventive measures for the derailment of large rail cranes

The derailment of large rail cranes will bring immeasurable economic losses to the terminal. Terminal management personnel should take corresponding measures to avoid derailment accidents due to lack of maintenance and other reasons. The specific preventive measures are as follows:

(1) Strictly monitor the use status of cart brakes and wheel clamps to avoid failure, dragging brakes, unilateral braking, etc.;

(2) Pay attention to check and adjust the rail sweeper during maintenance to avoid failure of the rail sweeper;

(3) If there is a sudden gust of wind during operation, the control should be disconnected as soon as possible, and the wheel clamp should be clamped. The operators under the machine should immediately use anti-climbing boots and sandbags to prevent the cart from sliding;

(4) Install windproof devices before the typhoon lands;

(5) To avoid the vertical collision of the trailer or other large engineering vehicles at the wharf when the rail crane is moving, strengthen the training of the drivers of the trailers and large engineering vehicles.