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Tips for M/E cyl head replacement:

Scope out the cyl head area IN ADVANCE. Check:
1. Exactly what size spanner for which component (e.g. Small CW pipes are usually size 17 or 19). Saves time trying different spanners and rest of the crew is judging how fast and accurately you work as well.
2. Gauge the strength needed and the space offered. If let’s say I need to hammer but the space I need to lift the hammer is limited, can I try using a pipe or extension spanner instead? Especially for the bolts of the joint between exhaust pipe and exhaust valve. Usually one one of the hardest parts of this job since working space is sibei awkward. You get the drift.
3. Have an idea what to expect when you disconnect certain connections. If I was slacking the bolts of an oil pipe, I would standby cotton rags to immediately use to prevent oil from dripping everywhere. And also the cover the mouth of the pipe, prevent foreign matter entering.

Okay for the actual job.
1. Hydraulic nuts loosening/tightening isn’t difficult, but if there’s miscomm between crew, this can screw up the job with most impact.
A) Memorise hyd jack hyd oil pressure as per manual. E.g. For mitsubishi UEC, cyl head hyd nut 62.7 MPa. For man B&W, 900 bar. Then memorise the loosening and tightening procedudd. VERY IMPORTANT. Confirm with the crew, how many rounds (usually people count in terms of 1/2 turn, 1 turn, 1.5 turns etc) to turn the hyd jack. We always want the hyd jack to be sitting fully before using; you’ll see the piston moving upwards when the hyd pressure increases. (if it doesn’t move, that’s another problem). For loosening hyd nut, there’s usually a practice of full tighten hyd jack then loosen 1 turn or something. Don’t want it to be stuck/seized after start pumping hyd oil to the hyd jack. Also confirm if they have a practice to make markings on the nuts? This may differ from crew to crew.
B) Make sure the stud threads are clean and not damaged
C) Likewise, confirm with the crew how many rounds/holes to turn the hyd nut after reaching correct pressure and hyd nut is now free to move. After the nut is loosened, make sure it’s still free to turn while they release/vent the hyd oil pressure.

2. When the cyl head is about to be lifted up, there should be another crew standing sideways (in line with the cyl heads) to check that the overhead crane lifting hook is exactly in line.

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