Telescopic cranes perform a delicate balancing act with every load, of course it is not easy to think of these monsters as delicate, but the fact is that one false move, freight out of balance can send this giant crashing to the ground. Keeping the necessary balance requires reliable operators, steady equipment, safe maneuvering, daily, monthly and annual inspections, serious controls and operational safety systems.
1. Daily inspections
1.1. Working rigs
The wires should be inspected for wear or damage before use. Look for worn areas, broken wires, corrosion, pitting, gouges, kinks or crushing. These are signs of weakness in a cable that may break under load.
1.1.1. What does the technical standard say?
The standard says that the cable must be replaced immediately if the following happens:
- 6 or more broken wires in a braid spiral.
- broken wires in the same braid of a braid spiral
- Deformations in the cable
- Evidence of heat damage of any kind
- Reduction in the nominal diameter of the cable
Friction is one of the worst enemies of wire rope, but friction can be reduced by greasing the rope regularly. It is suggested to use the lubricants recommended by the manufacturer, these lubricants are designed to stay attached to the cable and penetrate to its core.
The winch is also another component to be checked, it’s necessary to verify that the cable is well reeled in the winch. There should be at least 2 complete turns when the boom is fully extended. In addition, all accessories such as rings, shackles, screw tensioners and bridles should be checked. Make sure that all accessories are secure and show no signs of corrosion, wear or fatigue.
Inspect the gable for damage or excessive corrosion. Look for signs of stress that could cause the gable to collapse. Signs could be cracks or dents in the gable structure, cracks in the paint.
On lattice gables, check for missing or bent tie rods and damaged strands.
On hydraulic gables, the guides should be inspected regularly for excessive wear; a boom can increase your reach, but it must be in good condition to achieve the best balance. If the extension arm is used, check for bent or broken tie rods, missing pins and excessive wear on the sheaves.
Check air pressure and replace damaged tires immediately.
Hydraulic fluid and oil are the lifeblood of the crane, too little or too much of it can fatigue the entire system. Check for fluid leaks in or under the crane. Always use a manufacturer’s approved grade of oil.
1.5. Safety Systems:
These devices are built with protection systems to help keep their operation within design limits. Some systems prevent operation if an attempt is made to lift excessive weight or to push the crane beyond its capacity.
Any disconnected safety system should be reported and the crane should not be used until it passes inspection.
1.5.1. Load diagrams
The load diagram is designed for each particular crane based on tests performed by the manufacturer. The standards require that the clearly printed diagram remains in the cab. If the diagram cannot be seen or read, or if it does not match the crane in question, do not use the crane. In this case you should report it to the company safety officer.
Whenever any changes are made to the crane, new tires, bolts or whatever; record them accurately so you will know when parts were changed or repaired.
The documented daily inspection can provide proof of the condition of the crane when you started work in the event of an accident.
2. Monthly inspections
The standard requires that monthly inspections be performed in addition to daily inspections. The daily inspection log will help simplify the monthly inspections.
If the crane is older or if it has areas subject to increased wear and tear, it should be inspected in more detail.
The monthly inspection should include everything that is inspected on a daily basis in addition to the following:
- Inspect all welds for cracks, falling paint or rusted areas may indicate a potential problem.
- Inspect the entire crane for structural damage such as distortion or cracks in the main frame, gable and superstructure.
- Examine the sheaves for grooves or wear, look for signs of grooves on the sheaves, they may indicate excessive wear.
- Check safety devices and warning indicators, including load and gable indicators.
- Determine if there is excessive wear on drive systems, including chains, sprockets and belts.
- Make sure steering and suspension systems are in good working
- Inspect hydraulic and pneumatic hoses, fittings and tubes.
- Check for oil leaks, deformation of hose covers, leaking fittings that do not correct when tightened, and signs of wear or thinning of hose walls.
- Loose bolts or rivets shouldn’t simply be tightened, but replaced, as they may loosen because they have been tightened too many times.
- Carefully inspect all hooks for deformations or cracks, remove hooks that show cracks or are deformed beyond safe limits.
Some items of the monthly inspection should be recorded in a register that includes: date of inspection, signature of the person who performed the inspection, serial number or other identification of the inspected unit.
3. Annual inspections
This inspection should be carried out by a competent and careful inspector who not only fills out the documents and certifies the equipment but truly examines the unit.
For this kind of inspection it is recommended to consider the following:
- You should make sure that the crane is warm and that all fluids are at a proper level and pressure.
- Park the crane in a place where you can lower the gable to horizontal.
- On hydraulic cranes make sure you have enough space to extend the gable fully, unless the load chart doesn’t prohibit it, some cranes may tip over if you have the gable in a horizontal position.
The crane inspector will usually start with the stabilizers to make sure that the platforms are attached to the jacks and don’t slip out of place when the jack is raised. He will then look for cracks and creases in the stabilizers and stabilizer guards. Any defects can weaken them, thus increasing the risk of tipping.
Tires should be checked for correct tread and air pressure and for any damage.
On lattice gable cranes the inspector will check for missing or damaged tie rods, examine the main core for signs of damage or repairs.
On hydraulic cranes the inspector will look for signs of buckling or deformation of the boom that may decrease its strength. The base of the boom is inspected for cracks. Sheaves are checked to see if they are intact and have all the bearings. Bearings are inspected to ensure that they allow the sheave to rotate freely without excessive play.
- The load block and safety counterweight are examined to ensure that they’re properly secured and marked with their capacity and weight.
- Gable extensions and sheaves or davits are also inspected. As with lattice gables, the sections and extensions should be intact. The repair of any of these parts must meet the manufacturer’s specifications.
- Once the gable is inspected, you will be asked to lift the gable; the inspector will then check the rotation brakes and the cab locking pin.
- On latticed cranes, inspectors examine the safety brakes. Check that they’re secure and properly adjusted
- All warning signs and labels should be in place throughout the crane.
- Fuel tanks should be well identified.
- Finally, the inspector will examine the crane body from underneath to make sure it is in good condition.
- Monthly inspection records will be examined.
Remember, if you operate a crane knowing it is not certified, you may face legal problems.