Welcome to the official website of Guangdong Yongtong Crane Machinery Co.,Ltd

Yongtong Machinery

Guangdong Yongtong Crane Machinery Co.,Ltd Professional intelligent lifting solution service provider
0757-23357118 0757-23832122

How many tons can a bridge crane be overloaded? Learn about crane safety devices


Overloading of the bridge crane is absolutely not possible, lifting overload will bring pressure and damage to the equipment, and pose a safety hazard to the operator and workers. It is prohibited to lift heavy loads in excess of the rated load on any equipment and should always follow the manufacturer's specifications and instructions for using a bridge crane and do not attempt to lift loads in excess of the rated lifting capacity of the crane.


Most bridge cranes now have safety devices that help prevent crane related accidents. The following describes what are the safety devices of the bridge crane, and the role of these safety devices.

There are two types of safety devices for bridge cranes: electrical safety devices and mechanical safety devices.

First, the bridge crane electrical type safety devices are:

1, lighting switch box: can ensure the lighting of the work site, for electric bridge crane operators to provide a better line of sight.
2, electric crane bell: the main role is to remind the operator under the crane to avoid when the truck is running, or to remind the crane to start operating.
3, travel limit switch: the role is to prevent motor driven machinery offside accidents when the crane is running to the limit or the specified location.
4, emergency switch: installed next to the driver's cab, in an accident or emergency, so that the driver can easily and quickly cut off the power supply of the control line.
5, door cabin safety switch: installed in the door and hatch, to prevent someone up and down the crane or go to the crane platform above the work, the driver blind power supply accident.
6, anemometer: the main role is to cut off the power supply when the wind is large, to prevent the electric crane from being blown by the wind when the wind is strong and can not stop causing safety accidents. (Mostly assembled on bridge cranes and gantry cranes used in the open air)
7, fuse: protection control line short circuit.
8, phase sequence protector: mainly protect the main power supply phase sequence, the main power supply can not be turned around at will after the crane is debugging, if it will cause the electric crane to run upside down, the limiting device failure.
9, overcurrent relay: protect the main line and motor overload and short circuit.
10, the zero contact of the controller: protect the zero start, prevent the controller handle in the working position can be powered to start. An accident occurs when the motor runs on its own.
11, overload limiter: the main function is to cut off the crane lifting circuit when the lifting object exceeds the rated lifting weight of the crane to ensure the safety of the crane.

Second, the mechanical type of safety devices on the electric bridge crane are:

1, each part of the railing: in order to protect the safety of the staff, to prevent accidental fall accidents. A railing of not less than 1m shall be installed on the outside of the platform, the end beam and the trolley.
2. Hook safety card: prevent the rope from slipping out of the hook head when the crane lifts the object due to the larger distance between the two ends or the larger force.
3, track end baffle: the end baffle on both sides of the car and the car is to prevent the car and the car from offside accidents;
4, the car sliding touch the line baffle is to prevent the hook swing offside electric shock accident.
5, buffer: with the end baffle (bump block) joint work, is to reduce the car and car, car and track end bump block collision impulse (crane with the buffer is mostly spring type).
6, rail sweep plate: to prevent foreign bodies on the track, there is a rail sweep plate to push foreign bodies to both sides.
7, protective cover: fast drive shaft shield, hook shield, pulley block shield, etc., to protect the safety of moving parts, to ensure the safety of personnel, to prevent cast iron collision damage.
8, cab fire extinguisher: essential items to prevent circuit fire, generally powder fire extinguishers.