Why do big boats engines stop?

Re: Why do big boats engines stop? Steam and Motor Ships

The Mk2 VLCC steam ships from Mitsubishi were very good and reliable. This coupled with their normal boring runs of Gulf-NW Europe meant I tried to avoid them except when needing hours for my steam tickets. In the seventies the older steam ships were used more like oil tramps and you saw far more of the world even if it was steam a bit stop a lot progress.
Even better were the small 16 and 19,000t product carriers. Still had problems and lots of long hours but you went anywhere from Baltic, to Black Sea, Africa to Brazil.
Some of the runs ashore in Portugese Africa for example I will never forget.
Some larger motor ships in those days in my company were squeezed into engine rooms designed for steam turbines. We had one famous one where a cylinder had to be knocked off to get the engine in. She retained her boilers and all the rest of the steam plant for cargo pumping so you had the worst of both worlds. She was one to avoid at all costs.
Ships were growing in those days and mistakes were made. Company had steam ships which if you ran at full power the case hardening on the gearbox teeth would only last till Cape Town. They never were fixed but ran around at 4 - 8kts until scrapping.
Ship that sank was on its last voyage before scrapping in fact she had been destored once until last minute cargo came up. If I remember correctly chaps could not get the condenser overboard valve shut in time after the pipe ( about 5 foot diameter) fell to bits, before it went underwater - she took about 7 days to go under as the water tight bulkheads held up very well.


It was a young single mans game but overall it was a great life and you learnt a lot about life people countries rapidly if you grasped the oppertunities of getting ashor all you could,.
 
I can add a couply more. I had an engine overspeed in the rough weather last November because the ship was pitching and rolling so much the prop came out tof the water and the governor wasn't quick enough to slow the engine down. I also had one stop on low gear oil pressure because the pump lost suction on the same night.
Rgds
Bob
 
sometimes they stop because of water in the fuel ........ a distinct possibility on 'small' ships with low freeboard and poorly maintained tank vents

other times cos engineers pull bilge alarm cards so they can have a quite night in bed (when 'on the buzzer'), but when it gets rough water splashes on electrical items and go fizz ....

other times its because an earlier job was botched as a quick fix and the strains of rough weather (heavy vibration and props aerating) reveal the folly of 'quick fixes'

sometimes its because an engineer doesnt know where the 'reset' button is ........... amazingly

and a combination of them all /forums/images/graemlins/cool.gif
 
Re: Why do big boats engines stop? Steam and Motor Ships

Seems like Brian was enjoying the delights of Beira and Lourenco Marques in the 60s and 70s with no mention of Mombassa let alone the delights of Durban and Capetown.:)

Yes the progress of some ships could be stop and go and for various reasons depending on the propulsion system. Many ships would run port to port without a problem and in some cases this could be 3/4 week passages non stop between bunker ports. However there were some ships where the machinery was put into service and left to the ships engineers to complete development /forums/images/graemlins/smile.gif The P type Doxford with its bendy crossheads, the fix was to put a central bearing pad under the piston rod. and the engine that gets the prize is the little known Ruston AO . This was a compact medium speed diesel and available as in line 9 cylinders 4500 HP and Vee 12s and 16s. These appeared in the RFA Rover ships, the Baron Boats and Reardon Smith line where I spent 5 years learning to love their mysterious ways. There would be two engines coupled via a gearbox to a single shaft and for manoevering one engine would be running ahead and one astern with clutches to connect the required engine. Once clear of port the astern running engine would be stopped, restarted ahead and clutched in and balanced to the other engine for full sea speed. This was accomplished with a pneumatic interlock system .

Unfortunately these engines suffered from one or two faults and the sound of the falling pitch of the gear box whine as the speed was reduced to effect a repair was initially a regular occurence.

Piston rings could only run 2500 hours, exhaust valves burnt out, cylinder heads failed, flexible coupling elements failed and if not caught iin time overloaded the crankshaft thrust bearing leading to crankcase explosions, fuel pipes burst,injector studs fractured, turbo charger aftercoolers chocked. and that was just in the first few months from new /forums/images/graemlins/smile.gif

The Vee engines had their own problems such as losing the governor drive which would lead to engine runaway and as the engines had so little inertia the overspeed was too slow in reacting before bits came flying out of the crankase.

Yes interesting engines and an oil companies delight as they also burnt up to 600 gallons of lube oil a day instead of the normal 60 when things went wrong with the piston ring pack .

Two of these engines were donated to The Marine College in Cardiff for training,(exWelsh City) wonder if they are still there!

Yes life at sea can be eventful and the crew usually have the ability to get things running again one way or another . There is no better incentive than seeing a splodge on the radar getting closer and closer to a drifting powerless ship especially when one looks out of the bridge window and sees the rusty remains of an earlier casualty sitting on a tropical reef a few cables distance. (RD Sulzer forward turbo charger compressor threw its inducer blades.)

A great life for the unmarried and certainly saw life in the raw.

John
 
Re: Why do big boats engines stop? Steam and Motor ShipsSom

Really heavy weather, 1/2 way to Azores, met C/E in alley way said "Morning Lecky, whats that youve got" replied found this broken stud in the alleyway. "Check the bulkheads and let me know" OK Chief, with that there was a loud bang repeated about 5 times, then the engine stopped, ran to e/r found that the spare liner had fallen from its shelf, bending the top piston guide rods. If I remember correctly it took about 7 hours to get the mains going again, this was on a 6 cylinder opposed pistom B7W. now reduced to 5
 
Re: Why do big boats engines stop? Steam and Motor ShipsSom

The Royal Princess (now Artimis i think) had 4 of only 6 Pielstick 4.2 inline engines ever built I can only assume P & O got them cheap as they were definitely experimental. In the first year it was not uncommon for air start valves, relief valves, and the odd air inlet trunking to blow off the engine and bury itself into the deck head.
If you started 2 of the the propeller hydraulic pumps together then the main engine shut down ( a spike in the main engine governor control system) Siemens stayed with the ship for over 18 months trying to sort out spurious shut down signals to the main engines (no generators on this ship, not needed!!!!).
Going into San Francisco a three amp control fuse for No1 main engine blew and shut down the engine "no problem says the chief we have another". "No we haven't says the lecky there goes No2........and 3" then of course the lights went out.
Anybody who has had the pleasure of trying to train a cadet will know they are capable of just about anything. Including opening the air cocks of a running engine and stopping it with the stop lever. "Thought it made a bit of a noise" was his reply when asked by the chief as to what the f... he was doing.
If you're on a tanker it's not so bad when the lights go out but when the cargo talks to you it can be embarasing trying to explain the cock ups that happen in every engine room.
All of us have probably said at one time or another "oh but for the grace of god goes thee"
Worst things DO happen at sea!!
Bob
 
Do merchant ships suffer from diesel bug?

I suffered two engine failures with the bug. The first was when I ventured down to the tidal section of the Thames, the water was very choppy as there was lots of river traffic at the time. Lost one engine after clearing Tower Bridge and managed to moor on the South Dock pontoon. Spent ages clearing the system, fitting new filters that last lot had been fitted before leaving Windsor so had done very little work.
The second time was returning from Dunkirk 2000 lost both engines. Before this trip I'd drained the tank, filtered the diesel twice and topped the tanks up with new diesel, fitted new filters and flushed the lines, ran the engines for 8 hrs and changed the filters again before setting out from Gallions Point. luckily we were in convoy flanked by the Royal Navy and the RNLI so I was quickly taken in tow and deposited on the inner wall of Ramsgate Harbour.

Not have a repeat of this on the 2005 I ripped out the tank and fitted a complete new system with double filters of the easy prime type and keep the tank topped right up all of the time, I carry two gerry cans for this. this year I'll fit a circulation pump to move the fuel through a large truck filter while the boat is standing, this maybe over the top but as I'll will be doing a lot of solo cruising in the coming year I don't want dirty diesel to spoil my fun.
 
In general merchant ships do not suffer from the diesel bug as it ie removed in the centrifuges. However it is not uncommon to suffer from the bug in the crank case lubricating system where the effect can be even more costly and dramatic.

There can be many thousands of litres in a crank case oil charge. Sometimes this oil may become contaminated with water and due to the operating temperaures this becomes a breeding ground for THE BUG. These wee bugs create an acidic mixture which is able to etch polished steel. More than a few ships crankshafts have been wrecked by the subsequent damage caused within bearings by the presence of this etching. The same type of damage can occur in injectors and fuel pumps.

John
 
Re: Why do big boats engines stop? Steam and Motor ShipsSom

When I joined BP as a nav app in the late sixties, the older ships (c 1940s) had Doxfords or B&Ws. We used to spend a week in the engine room each trip and I remember one of the engineers (prob the 4th) taking me up on the top engine walkway and there were all these whopping great bits and pieces whanging up and down and to and fro. 'Twas a deep emotional experience for a young lad barely out of diapers, and confirmed I had made the right decision to join the deck department!
 
Re: Why do big boats engines stop? Steam and Motor ShipsSom

Fascinating bunch of stories here! Many thanks for the info!

For a matter of perspective though, there are a large number of merchant vessels chugging around the seas doing many thousands of hours each year, so even an un-intended stoppage rate of 1/100,000 hours is going to create a lot of incidents and quite a few headlines each year.

It's a bit horrific to look at leisure failure rates though. Average motor usage is under a hundred hours a year for the 20,000 or so vessels moored around the Solent, but they manage to create many hundreds of call-outs a year - and in addition many more are given a tow by passers by or friends.

Only back of the envelope guesses of course, but that's at least ten times more stoppages per leisure hour than the merchant fleet . . .
 
Re: Why do big boats engines stop? Steam and Motor Ships

No, I was Swires - had a lot of ex-BP colleagues. They generally seemed to think that Yokohama/Pago/Tahiti was an improvement on Gulf/Europoort!
 
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