Maintenance : Maintenance work is necessary to ensure that the crane is in good working condition. Failure to maintain a crane may allow minor defects to develop into major problems. Owners may then be faced with a large repair bill to put it right. More importantly, an accident may occur as a result of the defect, causing damage to life and property. This guide will provide some basic information on the general inspection and maintenance procedures for mobile cranes. It must however be stressed that the manufacturer's specifications on these should also be strictly adhered to. How to inspect and maintain mobile cranes Different types of inspections are scheduled daily, weekly, monthly and annually. The frequency of the inspections will depend on the critical components of the equipment and the degree of exposure to wear and deterioration. The general external inspection and maintenance schedule should include the following procedure:

External Checklist:

a. Inspect the entire crane superstructure for structural damage. Common damages such as distortions, cracks, corrosion, dents and bending can be very serious. Defects are critical if they occur in the frame, boom outriggers and slewing mechanism. Inspection should also be made on the welded connections of the structure. Hairline cracks or flaking of paint work at these areas are symptoms of a defect building up. Repair on structural parts of the crane must be surveyed by an approved personnel.

b. Inspect load bearing connecting parts of the crane assembly such as pins (ex. at the boom,), bearings, shafts, locking devices (ex, slew lock), counterweight brackets and bolts (or rivets) on the crane superstructure.

c. Inspect the hoisting mechanism of the crane. The wire ropes must be free from corrosion, fraying or kinking. It should be properly wound around the winch drum. The winch drums and gears must not be worn excessively. The gears should be greased regularly. The hooks are to be inspected for cracks or signs of
"opening up". The safety catch must also be in good working order.

d. Check the crane mounting to ensure that it is in good mechanical condition. Truck mounting for mobile cranes is similar to that of a lorry and all checks meant for such heavy vehicles will apply. A crawler should have its link belt and peripheral connections checked to ensure that these are connected properly and the wear is within safe limits. Once the above external checks have been done, the following internal checks can proceed.

Internal checklist
e. Inspect moving parts of the crane which are subjected to wear such as clutches, brake linings, pawls and ratchets, sprockets, gears, etc. Replace parts that are worn beyond safe limits.

f. Check lubricated parts and ensures that there are adequate lubricants and that these are not contaminated, especially at exposed parts such as the boom jack, outriggers, slewing table and pulleys.

g. Inspect the crane's engine and see that the beltings are at the right tension. Also top up fluids such as engine oil, cooling water, battery water, clutch oil etc. Ensure that guards for exposed moving parts are securely in place.

h. Inspect the hydraulic system of the crane. See that those, fittings, tubing and valves are in good condition. Any evidence of oil leak, abnormal deformation wear of these parts must be taken seriously. Failure in the hydraulic system during lifting operation can have disastrous consequences. See that the hydraulic oil level us at the manufacturer's recommended level. Top up the hydraulic oil if it is below the recommended mark.

i. Inspect the electrical system to make sure that these are working properly. Extra care must be taken on the control mechanism since wrongly or poorly connected electrical circuit can result in disoperation. Consult the manufacturer or local agent if in doubt.

j. Ensure that the gauges, (ex. boom length, boom angle, load-Radius, etc.) are giving the right reading by counter - checking them with physical measurement. k. The crane can then be turned on and have its controls checked. Operate all the controls and see that these perform properly the functions for which they are intended. Operate the out-rigging, slewing, derricking, hoisting and telescoping controls. Note any unusual movement, noise or vibration and have it corrected.