A ship lasts a long time.It will give you twenty years of service easily.Many of them are still running after 40 years.Ship repair equipment put on a ship..The mean time between failures for major equipment like turbines and boilers can be as high 600,000 hours.Now the life cycle of equipment goes through three phases.The first part is what the shipyards are plagued with, where all the manufacturing and shipyard defects show up the infant mortality period.That is where we try to work the bugs out of the equipment.Hopefully, by the time we finish the dock and sea trials, we have worked out those bugs.We can put into three categories those parts that are on the engines and the pumps that we have to replace or overhaul.The first thing we have to do in overhauls is determine whether or not repairs are necessary to a piece of equipment.
There are other parts, like bearings, which when they wear out don’t affect the performance of the pump except that the pump either works or doesn’t work.These deficiencies can also be picked up by vibration testing.Unfortunately, many of our ships do not have vibration test equipment and personnel on many of those that do, do not know how to take the reading right.But we have the same problem with electrical equipment.
Liability and Damage Avoidance
Now the customer — he is our problem. He wants us to fix it cheap, but he wants us to assume all the liability for the part for an indefinite period in the future. He can’t have it both ways. The results are incompatible. What your standard job order should define for the important equipment you overhaul is a Class A overhaul. A Class A overhaul should include all the work that you think will be necessary to restore the equipment to its proper working condition. This will replace all the short life items. It will insure that all the moving parts that could possibly wear, and the non-moving parts like the liners that wear, are corrected, and it will insure that the casing and the other infinite lifetime parts which are important to the integrity of the part, have a lifetime guarantee for the next overhaul cycle. If you do that, and if he buys that, then yes you have assumed liability if that part fails.
We had one such incident happen to us on a system that you would not think would need capping. It was an exhaust system on a diesel submarine, a very small exhaust system. If anything is going to be dirty it is going to be a diesel exhaust system. The exhaust system had been opened up. A shipyard worker read his newspaper, and when he finished it, he rolled it up and shoved it in the exhaust pipe. He did not want to throw it on the deck — that’s a fire hazard. We put the ship back together again. We ran that system and almost ruined the engine trying to do a heat run on it. The high back pressure is not good for a diesel engine, to say the least.