|Alatas Service||Field Service, Parts Supply, Workshop Repairs|
|Location||Bahrain, Middle East|
|Crane Type||Offshore Barge / Heavy Lift|
Alatas Middle East was contracted to carry out 5 Yearly Survey crane condition evaluation in Bahrain for an IHI IC-9563 crane that dated back to the 1970s.
This offshore heavy lift crane had been sat inactive for several months and downgraded from 500t main block to 200t. Alatas Worldwide were requested to carry out a complete crane condition evaluation so the crane could be deemed fit for use and perform a load test bringing the lifting capacity up to 400t.
Job Scope for Crane Condition Evaluation in Bahrain
- Onsite engineers supplied to carry out inspection
- Remedial work scope to correct any potential issues with workshop
- Supply of spare parts as required
- Provision of water bags to carry out load tests
Local re-engineering of worn sheaves
During the inspection, our Field Service Technicians found 14 boom sheaves to have lost the hardened material at the root area and required to be changed. Due to the lack of availability of these sheaves, the Field Service team sent the original spec drawings of these sheaves to Alatas Middle East to be cast locally in the Dubai workshop. Once the sheaves were ready, the machining of the bore took place and was given tolerance of between 309.98 – 309.93 for the fit of the bearing. Once the sheaves were already, they were sent onsite and changed out.
Changeout of Slew Mechanism
The second main concern found during this crane condition evaluation in Bahrain related to the slew mechanism rail pads. These also had significant wear, so our technicians recommended a changeout. Similarly to the sheaves, we could not order the required spare parts. So the team sent the original specs for the slew mechanism rail pad to Alatas Middle East to be manufactured in Dubai. Our workshop engineers followed the correct dimensions and material, as stated in the manual.
This part of the job concerning the rail pads posed a slight challenge as there was no set procedure. Our technicians came up with the solution of the IHI IC-9563 crane being jacked up from jacking points, lifting the slewing rail off the roller wheels so the slewing rail could then be lowered down, providing access to renew the pads.
Using our Global Network of Expertise
The onsite supervisor of Alatas Middle East called in the help of the engineering team from Alatas Aberdeen to ensure the procedure to change the slew mechanism would be performed efficiently and safely.
The condition of the original onsite jacking equipment was suspected to be unsafe due to prior usage. The team agreed that new jacks would be supplied lifting AFT side of the crane with 4x 200t jacks. There would also be additional plates and spacers to distribute the displacement of the load. There were also spacers and safety chocks in place so that we didn’t have to leave the load on the jack, enabling us to take the tension off the jacks.
The anti-uplifts were removed and the crane was jacked up, changing the AFT rail pads before fitting back what was required, then shifting to complete to FWD side. In total around 130 rail pads were changed.
For this crane condition evaluation in Bahrain, inspections carried out on negative brakes and motor brakes, taking measurements of all brake pads to check they were all within tolerance changing pads where required.
After the procedure, our team then carried out a full greasing routine on all crane points, including cleaning of shafts for travelling sheaves due to neglect. This was followed by a check of all electrical systems and functionality.
Our team performed pre and post load tests of the boom, critical welds, winch base foundation welds and hook blocks before oil sampling was carried out from all points to be sent away for analysis to be sent back to the client.
Load Test of 3x Hook Blocks
Load test took place at a radius of 60m load applied to 100t all motions tested then a static load test of 110t was carried out held for 5 minutes and witnessed by ABS.
Load test took place at a radius of 42m load applied to 200t all motions tested then a static load test of 220t was carried out held for 5 minutes and witnessed by ABS.
Load test took place at a radius of 31m load applied to 400t all motions tested then a static load test of 440t was carried out held for 5 minutes and witnessed by ABS.