Checks and Maintenance

The engine room crane has a Safe Working Load (SWL) limit, which should never be crossed at all times. The crane manual is the best source to understand when and what inspections or maintenances are required.

1. “Not To Forget” Daily Checks

Prior to carrying out any operation using an engine room crane, a brief check on the following should be done:

  • Check the lubrication
  • Check the noise level by operating the crane without a load
  • Check the heat generation
  • Check all the limits and trips are working properly
  • Check the contact areas of electrical equipment
  • Check the brake operation
  • Check the condition of the clamp in the hook

 

2. Follow Proper Planned Maintenance

The planned maintenance of the crane should be followed properly and the following inspections should be done as per the working hours prescribed by the makers

  • Overhauling of motor
  • Greasing of wires
  • Renewal of wire ropes
  • Annual survey
  • Load test
 
3. Ensure Adequate Lubrication
 
In an engine room crane system, two lubricants are used:
  • Grease: Wire ropes, rollers, and plain bearings are applied with grease for smooth working. Reduction gear for hoisting and sewing is not applied with grease. Check the greasing of these parts and replenish the grease every 2000 working hrs. or as prescribed by the makers. Ensure not to excessively apply the grease on moving parts as it may cause overheating at the time of rotation, which can have adverse effects.
  • Oil: Lube oil is used for the lubrication of ball bearings and roller bearings of hoisting and slewing gears. Check the oil level regularly and replenish once the level is below the mark. The condition of the oil needs to be observed for stains, foam, and dust. Renew the oil if the condition is not up to the requirement
 
4. Check the Minimum Requirements Of Wire Ropes
 
The wire rope of a crane is the main operational part of the system, which is responsible to lift and move the load from one part of the engine room to another part. Following maintenance to be performed on the wire rope:

 

  • Wind the wire rope in the correct way to prevent kink of the rope
  • Lubricate the wire rope at regular intervals to reduce internal friction and prevent corrosion
  • Before greasing the rope, clean it with a cloth to remove dust and foreign matter

Requirements for the renewal of wire rope:

    • When the diameter of the rope is reduced by 7%
    • When the number of visible wire fractures is 15 over the length of 6 times the wire rope diameter
    • When the number of visible wire fractures is 30 over the length of 60 times the wire rope diameter
    • When a kink caused at some part of the rope does not restore to its original shape
    • When the rope is reduced in length
    • When the rope is twisted out of shape
    • When the rope is deemed unusable because of rust or corrosion
 
5. Inspect The Gears
 
Gears are used to hoist or slew the crane to manoeuvre the load at the desired location. Following inspection and maintenance are carried out on the gear assembly:

 

  • Drain the gear case oil if the condition is not good and after cleaning the case, replenish it with fresh lube oil
  • Keep a check on the gear case noise while the crane is in operation
  • Measure the thickness of the gear teeth and if has decreased by 20-25%, renew it with a new one
  • Inspect the gear for damage to teeth and renew it with a new one if the damage is more
 
6. Check the Condition Of the Sheave
 
Sheaves are used to carry the wire ropes from the gearing chamber to the hook of the crane. A number of sheaves are installed in the assembly for the wire to move smoothly for operation. The following inspection must be carried out:

 

  • Inspect the groove which is in contact with the wire for wear down
  • Check all the sheaves for freedom of rotation
  • Check the trueness of sheaves. It may bend if the load is lifted obliquely
  • Check for cracks and broken circumference on the face of the sheave
  • Check the bearings provided in the sheave assembly
  • Check the bolt and the pin holding the sheave in place are in good condition
  • Check each sheave to insure the rope groove is smooth and free from burrs, or other surface defects
 
7. Carry Out Hook Maintenance
 
The hook assembly is such made that while the load is ON, it can rotate 360 degrees to adjust the position of the load and it comprises bearings and drums. Following maintenance and checks needs to be carried out:

 

  • Lubrication of bearing is to be done regularly
  • If the partial wear of part to be suspended with rope is not much worn, use a grinder to make it an even surface
  • Never repair any crack by welding
  • Make sure the dowel pin holding the hook is in position. Measure the pin diameter and replace it if it’s worn out
  • Ensure the safety latch spring is in working condition to avoid jumping off the load
  • If a rotation lock is provided, check its operation
  • Check the material for brittleness, cracking, and hardness during an annual survey
  • If the part used for rigging the rope has worn out, check its shape (concave) and repair or replace it as per the condition
  • Check the throat opening of the hook and if the throat opening exceeds 15% of the original opening, or if the hook is twisted more than 10 degrees, replace the same
 
8. Check The Brake
 
The engine room crane is equipped with an electromagnetic brake with a fail-safe arrangement. This is the most important safety arrangement provided in the crane. Following maintenance and inspection needs to be carried out:

 

  • Measure the distance between the magnet and the armature. It should be approx. 0.5mm around the circumference(refer to the manual for the exact value)
  • If the gap is more or less than the recommended value, adjust the braking power nut to reach the required gap
  • If any overhauling is carried out, supply the current to the magnetic coil only to confirm that the running shaft is operating without any resistance
  • The electromagnetic brake is operated by the brake lining. Check for moisture on the surface of the lining to avoid slippage
  • Check for signs of overheating and mechanical damages
  • Check the tension of the spring that carries the brake during the overhauling of the brake assembly
 
The engine room crane is an assembly of various important parts, which need equal attention as any other machinery in the engine room. While the engineers and engine crew are responsible for operating the crane, it is the core responsibility of engineer officers to ensure no breakdown of the crane occurs by following correct operating procedures and maintenance schedules.
 
For Advanced Read, check out:
DECK MACHINERY PROCEDURES AND OPERATIONS (2nd Edition)

Log in

Log in with Google

Log in with LinkedIn

Or

Don’t have an account? Register Now