Overhead crane operation safety rules and safety technology

 1-ringing from the car. From the car to a smooth, steady levels of acceleration.
 2, first class hanging objects, should the goods hanging from the ground 0.5m, then down, in order to test the reliability of the brake, then normal operation.
 3, prohibits overload operation, the estimation is unclear or near the rated load of the goods available two files try hanging. Two hanging file can not afford, and then not use direct lifting high gear. 4, prohibiting oblique hanging, stayed.
5, lifting goods, prevention of sudden lifting, when the rope nearly straightened (taut), to adjust the size of the car's position while lifting one side, to prevent oblique hanging. Similarly, the landing should look at what manner, in order to ensure a smooth cargo.
6 to prohibit lifting buried in the ground, the condensation in the device relative to the ground and the vehicle cargo collusion.
7, hoist gantry crane  operation, to prevent the hook or other lifting a greater swing. Such drivers should be proficient in the "steady hook technology." "Steady hook technology" is that when the hook travel pendulum swing back when the most significant yet, the trolley (cart) to hook swing tour with the most significant step in the direction to offset hook swing back, giving the hook stable.
8, cranes lifting goods banned from the person's head over, lifting goods prohibited to stand on. Lifting should follow the specified channel, more than 0.5m above the ground objects, but not higher than 1.5m.
9, the driver in the job following shall send a signal (-ringing):
(A) lifting, falling cargo, starting size car;
(2) cranes from blurred at passed, to a continuous-ringing;
(3) Cranes in the same layer or another layer close to the cross inside another crane;
(4) when lifting cargo close to personnel;
(5) In other emergency situations
10 cranes in the normal operation of the process, prohibit the use of emergency switches, limit switches, and other means to fight against car parking.
11 cranes in operation prohibition overhaul.
12, prohibit cargo cranes hanging in the air long-term stay. Crane hanging goods, persons linked to prohibit drivers and leave work.bridge gantry crane 13, loading and unloading of container or other cargo should pay attention to:
(1) check whether the packaging is solid and strong lifting symbols
(2) linked to withdraw all personnel before lifting carriage
(3) handling a large plate or cutting edge of the workpiece, use special clamps or special tools. Wire rope lifting and hanging objects must be in the rope between the pad to the pad material.
14, a significant drop in voltage or in the case of electricity ruin, you must disconnect the main switch, pull all the controllers to zero.
15, a sudden failure of the brake lifting mechanism emergency measures. When found defective brakes,Steel crane a warning signal is issued at the same time, playing against car, pull the lift controller to the appropriate grade, repeated use of this means to size car to a safe location, and then lower cargo.
If the brakes fail while lifting mechanism did not work, immediately turn off the cab master switch, the brake solenoid power, brake brake.
16, open operation, when the wind is greater than six or more, you should stop the operation.

The concept of the crane

Crane (Crane) is a crane is a for loop, intermittent movement of machinery. A work cycle include: extract extract means to put items from the lift, and then move to the designated place lower level items, followed by a reverse movement, so extract unit returns to original position for the next cycle.

Usually by a  hoist gantry crane  hoisting mechanism (the items up and down movement), operating agencies (the lifting movement), luffing and slewing mechanism (the article for horizontal movement), plus the metal body, power units, steering control and the necessary combination of auxiliary devices.
In bridge construction crane used in accordance with its structure and performance of different, generally can be divided into small light lifting equipment, overhead type crane and jib type crane three categories. Small light lifting equipment such as: jacks, hoists, winches, etc.. Girder bridge type lifting machinery such as  bridge crane  , gantry cranes. Such as fixed jib type crane slewing cranes, tower cranes, truck cranes, tires, crawler cranes.

Within a certain range vertical lifting and horizontal multi-action lifting heavy lifting machinery. Also known as the gantry crane . Belong material handling machinery. Crane's work is characterized by intermittent exercise to do that in a work cycle reclaimer, transport, unloading and other activities of the appropriate agency is working alternately.

Rope breakage caused the accident

a, Wire Ropes, broken stocks not in time, replace
b, a sudden fall hook, hook, trolley, etc. retaining rope pulley or no damage to 0 lead rope off the tank,bridge gantry crane thereby squeezing off the ropes
c, height limiter does not work, pull off the hook rope touch trolley beams

Other safety device is damaged, removed or malfunction caused the accident

Such as brakes, weight limiter, height limiter, slewing limit, luffing limit, limit walking carts and so on.

Design, manufacturing defect caused the accident

1, the design deficiencies such as lack of stability of the tower crane, one-sided pursuit of arm length performance,bridge crane tower rigidity or insufficient strength
2, manufacturing defects, random substitute materials or main material does not meet the criteria
3, does not comply with the welding process standards, there is slag, cracks, key size, or there is not enough Weld weld defects such as
4, the safety device failure,gantry crane and other protective devices are not perfect

Connecting bolt fatigue, loose lead to accidents

Construction machinery and equipment under JG/T5057.40-1995 high strength fasteners Standard: high-strength bolts, nuts, dismounted again after use, generally not more than twice.hoist gantry crane Remove the bolt and the nut must be free of any damage, deformation, slip teeth, missing teeth, rust, screw roughness changes in the larger phenomenon. The actual use of the user can do very little, but must pay attention to strengthening the inspection of high strength fasteners, fastening, maintenance, and periodic replacement, to avoid mix.

Pin shedding caused the accident

a, cotter pin traverse cut off the trigger pin
b, the installation does not install or replace the cotter pin with pliers wire
c, do not install the platen or cotter pin that will pin and structural welding; (pin weldability due to the difference in the shock impact is very easy to open welding,overhead gantry crane causing the pin to fall off.)
d, Shaft damper spring pad or fastening bolts without tightening is not strong long-term vibration and fall off,Steel crane do not work cause the pin off the platen
e, triangular baffle arm joints deformed due to repeated removal or open solder, lead off boom pin.

Key parts of the steel base material fatigue caused by cracks or critical weld cracks

Fatigue cracks are a variety of factors, and design, manufacturing, materials related, but most of the fatigue cracks close relationship with the long-term overload is the gradual accumulation of results.bridge gantry crane With China's construction technology revolution, construction speed leaps and bounds, three days floor no longer a myth, in the past few years, a few months to complete the project becomes complete. Such a fast paced and more attention should be paid equipment standard operation and maintenance work, the opposite is the original date equipment at specialized management agencies, machinery has been optimized at the most streamlined, functional greatly weakened, and even some companies simply do not exist equipment management department. Not only that, some leaders in order to improve the speed of construction,hoist gantry crane to "break people do not Xiema" tactics are commonplace. As everyone knows, "horse" is also tiring and long illness, when, if not well-fed, care will be "stumbled." At first only a small steel fatigue crack extension reaches a certain level will slowly cause the accident, as we always check, timely detection and timely treatment, can avoid such incidents. Prone to fatigue of the site are: base section and the bottom beam connections, diagonal brace to strengthen the above section, or standard section of the main limb or connected sets at the weld, the tower at variable cross-section, the upper and lower bearings,overhead gantry crane slewing tower , the top lower main limb or ear panels.

Comments: steel and weld fatigue caused the accident is also more link. Used for many years more devices are more accidents due to fatigue, many accidents are fatigue and illegal operations combine to happen.

Base does not meet the requirements to cause the accident

a, failure to specification requirements for ground endurance test, because of the foundation bearing capacity is not caused by tower  bridge gantry crane  overturning
b, not request brochures construction, the foundation is too small for the tower crane various working conditions Stability
c, bolt homemade reach specification requirements, bolt fracture initiation tower crane overturning
d, anchor bolts and foundation welded steel. Due to bolt material mostly 45 # or 40Cr, welding parts prone to brittle fracture

1.4 tower crane attached undue cause accidents

a, the attachment point above the tower  overhead gantry crane  independent lifting height exceeds specification requirements
         b, attached to the pole,jib crane attached to pitch without calculation, design arbitrarily increase

Poor working conditions, control of overhead crane accident

Some of metallurgical enterprises, mining enterprises, machinery manufacturing enterprises,  hoist gantry crane  operating environment is very harsh. As smoke from various smelting furnace; various pneumatic, electrical machinery, machinery roar; addition of sand, hit the dust and noise venue box; annealing, water blasting operation, water vapor, etc., tend to make the day truck drivers operating in a inaudible, invisible harsh environments. In this condition occurs, "roll over" accident, the accident has happened often, resulting in serious consequences, the driver can be aware of. In order to prevent "over volume" accidents, the best solution is to install limit alarm device. I had a few years ago where the business case in the fight, water blasting site running 17 # day vehicles designed and installed such devices. Detailed control over volume process that  Steel crane  in operation, when the hook set up, once the carom limit cross-foot (regardless of what causes "roll over", hooks groups are bound to the first strike against the corresponding horizontal ruler or other limit switches normally closed off within an indirect action part), horizontal ruler starts at the limit lifted, resulting in limit switch normally closed off at the same time, with linkage alarm device for closing the normally open points, electric horn sounded, drivers will inevitably perceive, immediately take emergency control measures, you can avoid the "roll over" accidents. The car previously occurred almost every year "over volume" accident, since the installation of such a warning device, has been unharmed. Such other types of alarm limits appropriately improved control system, can be used, and in the non-concentrated smoke, loud noise  gantry crane  working environment is also necessary to install an alarm device in order to achieve safety. Limit alarm device schematic diagram Note: This circuit can protect the disk from the main circuit over current relay coil bottom to take power, but also through the volume lighting, bells take power with isolation transformer. Small power electric horn or bell installed in the cab, you can use motorcycle suspension cables or spare power supply cable line two. Limit switch with L × 10-31 type limit switch, which is still connected normally closed limit circuit, normally open alarm circuit connection.