During the dark ages of computers and asset management, the 1970’s and early 1980’s, there was a company that operated large ocean going integrated tug/barge systems.
The tug engines were twin 5560 HP V-12 diesels.
There were 5 parts of these engines that were tracked. There was an index card for each item and notations were made whan any piece was changed.
The vessels had no computer systems but the First Assistant Engineer brought a personal IBM type computer aboard while the Captain had purchased a Commodore 64 and was writing programs for it in Basic.
Each engine had a counter attached that gave cumulative operating hours and each piece tracked had the engine hours at installation noted.
The pieces and guidelines for changeout were:
Heads 10,000 hours, later changed to 12,000 hours
Right hand intake valve 3,000 hours
Left hand intake valve 3,000 hours
Right hand exhaust valve 3,000 hours
Left hand exhaust valve 3,000 hours
The above items were for each cylinder for both engines, giving 120 items to be accounted for.
The First Assistant Engineer wanted to create a program to track the data and find out the status of each part. He bogged down on his program and mentioned the problem to the Captain.
The Captain wrote a fast and dirty basic program that compared the engine hours at installation to the present engine hours for each item and gave a printout of the status of each item.
It took about 2 days to enter the data and write the program which ran through it all in about 30 seconds.
Conditions were, “OK”, if under the replacement hours, “Will need replacement in XXX hours” or “Overdue for replacement by xxx hours”
The entire Port Engine was overdue by no less than 1000 hours and sometimes quite a bit more.
This sent a shockwave through all Engine related personnel.
Although information had been entered on the index cards, no one had ever made any practical use of it.
The economics:
These vessels cost about $2,000 per hour to operate.
The failure of an exhaust valve meant stopping the engine and changing it out and took about one hour.
(In a true disaster, the Engineers had bypassed the air/oil interlock that prevented the engine from starting when it had no oil pressure. The interlock had failed and there was no replacement immediately available. They shut down for a failed exhaust valve and when they restarted, no one turned the lube oil pump back on. The engine was destroyed and replacement cost $1 million.
In addition, about 1/4 of the revenue of the vessel for a whole year was lost while waiting for a replacement engine to be built and delivered.)
The failure of an intake valve would be another disaster. In general, the valve head would drop into the cylinder where it would get mashed into pieces about the size of a marble. In the process, it would destroy the other intake valve, the head, the piston and liner. This would generally cause an emergency port call and take a full day or two to repair.
In about 14 years of operation we never experienced a head failure.
So preventive maintenance was essential but before the advent of computers there was no good way to keep track of it.
The end of this story is that the Company went into high gear and replaced every part that was overdue. Right after they finished, the engines were started one morning and the lube oil pump failed to provied full pressure to the Port engine. It was severely damaged but not destroyed as was the Starboard one on the previous occasion. But the money was not there to repair it and the Company went bankrupt.
