Why do big boats engines stop?

Cutter

Cutter

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Not a wind up but was wondering why (big) boats like cargo boats get engine failure, especially when its rough (vis a vis the Vindaloo last night)?
Is it cos water gets in the lines, is it cos the engines go wonky if its rough, is it cos crew are doing something wrong?
Just seems to be common to see boats in distress in bad weather with engine failure. Of course engines may fail all the time and we dont get told cos the rough weather isnt pushing them onto an oil rig or lee shore.
Know some of you have been proper Mariners so whats the reason?
 
One possible reason is water finding its way into the fuel system. The tanker Braer, which suffered engine failure in the Fair Isle channel some years ago was totally wrecked west of Sumburgh Head in Shetland with the loss of about 80,000 tonnes of crude oil. The initial cause was spare sections of cargo pipeline, which were stowed on deck, breaking loose from their lashings in heavy weather and fracturing a fuel oil vent pipe, allowing sea water into the tank.
 
is it this [ QUOTE ]
Just seems to be common to see boats in distress in bad weather with engine failure

[/ QUOTE ] or is it that you hear about them only in bad weather?

interesting point that I am sure will bring out the facts...........
 
The usual reason as with the Braer is water.
Ships take on board a relativly poor quality fuel in general which has to be centrifuged before use to remove impurities and water. This cleaned fuel is purified into day service tanks and often there are two ie one filling and one in use.

Sometimes in heavy weather the engineers omit to keep checking the in use tank which has been purified and in heavy weather it doesn t take much water to get in via the deck air vents and fill the outlet line to the engine with water.

There are water drains on the bottom of these service tanks for removing this water and on occasions in the North Pacific I have seen these drains being held open when a deck vent has failed in order to keep the engine running on clean fuel.

Normally the deck vents are supposed to close when hit by a wave but sometimes they don't.

The service tank has a lower section below the fuel outlet to collect such water but it isn t a very big volume.

Things can get frantic when an engine stops for this reason as all the water has to be drained from the fuel lines and then the whole system reprimed. There is always the chance of the fuel pumps having been damaged whilst trying to pump water and replacing pumps can further delay the restart.

I have experienced this many moons ago and it took about 2/3 hours to get underway again. That was on a rather agricultural 3 cylinder Doxford Engine on a ship called Great City.

John
 
Yes, really good answer. Let me add a couple of more exotic causes within my experience:

1. Containership, North Pacific. Tier of containers smashed off by wave take mushroom vents into underdeck passageways with them, underdeck passageways flood up, doorways from passageways into ER open inwards because they are secondary ER escapes, not properly dogged, one door fails and water hits main transformer, shorting it out, resulting in blackout and main engine stop.

2. East German built bulk carrier, North Atlantic. 4E starts fuel transfer pump, main engine stops because cabling for fuel transfer pump runs too close to ME automation cabling and surge trips automation circuit, resulting in main engine stop. Admittedly not heavy weather, that one, just lousy shipbuilding...
 
Regardless of the very sensible answers given elsewhere, any engineer knows Mr Sods three laws.

1. Anything that can go wrong will go wrong sometime.
2. Anything that does go wrong, will go wrong at the most inconvenient time when you can least afford to do without it.
3. The best way of preventing something going wrong is to carry a spare.

Now, would you like to repeat the question?
 
As chief engineer I got used to being called because the engineers wished to stop an engine to fix a fault or because one had decided it wanted to stop.

I was amused to awoken one morning when we were due to arrive at the pilot station at Durban to be told the engineers couldn t stop the starboard engine:) The ship was at that point circling the bay to the melodious tune of two 9 Cylinder Ruston AO's chattering away at half ahead.

The cause......A pinhole in a diaphragm fitted to the pneumatic control system. Yes as big as these engines may appear they can cease operating as intended due to the most insignificant fault.


John
 
I believe that the biggest problem with small boats is that there are many boats out there where it is impossible to get into the fuel tank to clean it. Every thing is fine and the engine enjoys a decent diet of relativly clean fuel until the boat encounters rough weather. Then all the sludge sitting below the tank outlet gets stirred up and finds its way into the filters and suddenly the engines become starved of fuel.

This is a possible problem with boats such as elderly westerlys where the tank has no hand hole and the fuel outlet is from just above the bottom of the tank.

John
 
The Union Star, which the Penlee Lifeboat was launched to assist, was an almost new ship which lost all power. If I remember rightly, manufacturing waste in the fuel system was one explanation.
 
Captain Sir, I think we have water in the engines.
A1XY1C.jpg
 
Re: Why do big boats engines stop? Steam and Motor ShipsSom

Some memories from my 16 years

Steam
4E sticks screwdriver through boiler fuel pipe
Ran out of distilled water
Low Pressure Turbine coupling failure
High Pressure Turbine gear pinion shears
Chief Engineer takes boiler controls to bits and shut boilers down
Filled boilers up with water and carry over to turbines
Empted boilers and shut down on low water
Controls failure and turbine to full power as approached Forth Rail Bridge 220,000t VLCC exciting
All control air compressors failed
Main Condensor Overboard pipe failed and vessel sank

Diesel
Scavenge fires
Water in Fuel
Dirty MOD fuel en route to Falklands resulting in burnt out exhaust valve
Waste heat boiler fire
Generator failure many times ( we only ran one when full away)
Fuel valve seized
Liner cracked
Bedplate cracked
 
Re: Why do big boats engines stop? Steam and Motor Ships

(I feel I have to ask - were you in BP?)

Pretty good list!

A couple more diesel ones:

Rag in luboil (apparently, according to a Salvage Association surveyor, the commonest single cause?)

Crankshaft breaks, for no good reason at all (honest, this really happened, but B&W were not as surprised as they might have been!)
 
Re: Why do big boats engines stop? Steam and Motor Ships

This seem to be many good stories lurking behind some of these posts - would some of you Mariners care to expand - Brian's laconic 'boat sank' might be worthy of expansion. How often would a major trip be free of incident or was there always some (melo)drama along the way? Its a way of life I (and I guess many on the forums) can only dream of. Please continue.
Richard
 
Re: Why do big boats engines stop? Steam and Motor Ships

Were we collegues in arms then?

I was not actually on the poor old Ambassador but later served with those who were.The rest I was either on watch or the long hours putting things back together on all the other incidents.
 
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