How do they service ships at sea

[iangrant]

with "small" marine engines the service interval is 100 or 200 or 500 hours, oil and filters etc....

So if a container ship is at sea for weeks is some poor fella changing the oil all the time with the engine running??

Just a daft thought?


Ian

 

[smeaks]

in line purifiers and filters.

 

[Tidnock]

My guess would be; low revving engine, large uncompromised oil capacity, resulting in longer service intervals.

 

[Major Catastrophe]

They carry a team of service engineers with them.

 

[iangrant]

and

They carry a team of service engineers with them.

with filters, oil pump out, impelors, fan belts. Do they stop to do it??

 

[hlb]

In some cases they have as many as four engines and a couple of generators. Any combination of which can power the ship. One will be normally always stopped for a service.

 

[Divemaster1]

Flying to Norway for a ship naming ceremony this week-end, I will ask... but this will be on a multi-engined / multi-generator vessel with what I would suspect having diesel electric capabilities... (not looked at the spec).

But know that they all have oil purifying systems, do carry engineering crew and spare parts (beyond our normal thoughts of parts) when operating at sea for a month + at the time...

Cannot comment on really large single engine ships, but suspect that they can isolate cylinders... whilst others are operating..

 

[sarabande]

In some cases, there is a oil monitoring system installed as part of th engine management.

It analyses the oil in realtime to see if there are any metal bits, and checks the results against a database of engine parts such as the piston head, bearings, etc. to give advance warning of any issues.

search for FOBAS.

 

[Giblets]

A friend of mine used to be 2nd engineer with the Shell tanker fleet and he would regularly tell of how they would change a prop at sea after it had thrown a fluke. Something to do with ballasting down by the head. Now that is impressive.

 

[Tank]

A friend of mine used to be 2nd engineer with the Shell tanker fleet and he would regularly tell of how they would change a prop at sea after it had thrown a fluke. Something to do with ballasting down by the head. Now that is impressive.

i reckon he was winding you up

 

[Bilgediver]

i reckon he was winding you up

It has been done but not regularly. We removed twin propellers on a jack up oil rig on location and replaced the outside deep sea seals.

Ships main engines are designed for continuous running so either have duplex filters where one filter can be changed while the other is still in use or rely on suction strainers and centrifuges. The centrifuges are not on line but have their own by pass system an operate in port as well as at sea. As well as cleaning the oil they can be used to wash the oil as well to help remove acidity.

The fuel is also centrifuged before use up to day tanks from where it goes to the engines. Some ships may have just one day tank which is receiving centrifuged oil as the engine is taking it.

The big diesels can run with cylinders isolated by shutting off injection but this is unusual . Should there be a problem then it is not unusual to arrange to stop and fix it. On multi engined ships then only the faulty engine would be stopped and the speed reduced to prevent overloading the good engine.

Ships which do not have oil monitoring equipment pass oil samples to the contracted oil company ie Castrol, BP etc on a regular basis and so are able to watch the progress of the oil contamination in main engines, generator engines gearboxes and stern tubes and take appropriate action when necessary.

Maintenance of the main propulsion is done in port and other machinery at sea and will be done either by the ships engineers or using the help of riding crews who fly out specifically to do certain jobs and then fly home.

 

[Sundowner Portofino]

Got a mate who is a 4th Engineer, in-line filters and pumps that can be by-passed I think.

The bit that amazed me is that run on stuff called 'bunker fuel' which is so bad it has th consistancy of sandy gravel to start with, so they are forever changing filters and pumps.

 

[old_salt]

I have had a good smile at this thread.
Changing props at sea!! well yes it is feasibly possible and may have been done somewhere at some time.
But in reality it was just a paper exercise for the jun engineers to explain how to do it to the Chief Eng in his day room with a full glass in his hand.
My days are from the late 50s early 60s and we had a spare prop on the poop deck made of cast iron so it would have lasted about a fortnight and got us home.
Chiefs would put questions to the Jun's to get them thinking all sorts.
One I remember was how do you unload No 1 hold with all the winches out off action and only the aft windlass working?
No shore cranes.
and another how do you refit the spare prop at sea with only the the fore deck windlass working.

 

[old_salt]

Got a mate who is a 4th Engineer, in-line filters and pumps that can be by-passed I think.

The bit that amazed me is that run on stuff called 'bunker fuel' which is so bad it has th consistancy of sandy gravel to start with, so they are forever changing filters and pumps.

Yep in-line filters and pumps that can be by-passed striped and cleaned also there is always two of each and usually some other pump will have the capability to do the job as well.
The stuff called 'bunker fuel' comes in all grades from Bunker C which is as thick as tar and needs to be heated up to get it to work that was for boilers though.
Not to sure about the big smellies I think they use gas oil but yes it is stored on both steam and motor in a bunkers "measured in tons" and then transfered to day tanks.
I was on Steam Turbines.
We have heaved too and removed a main engine condenser end covers and located and plugged leaky condenser tubes at sea.
Well it was in the middle of the North Atlantic to be precise, and it was on one of the calmer days thankfully.

 

[epervier]

The answer is really simple, ask a chief engineer in the merchant navy,

the response, you don't,

you service the engines alongside, when loading and unloading, and major overhauls every 2-3 years in dry-dock.

and if it fails at sea,

you fix it at sea, or get tow-age to the nearest port with repair capabilities.

and as a footnote, He said anything with piston diameter of less than metre and a half is just a toy.

 

[Kukri]

Warsash Maritime Academy have a a handy website, intended as a resource for young professionals, here:

http://www.marinediesels.info/

It tells you pretty much what you want to know and a fair bit more.

 

[Nautibusiness]

Warsash Maritime Academy have a a handy website, intended as a resource for young professionals, here:

http://www.marinediesels.info/

It tells you pretty much what you want to know and a fair bit more.

I was at the maritime college in the mid late 80's!

It was my induction course before heading to sea with the then P&O Containers Ltd.
I was actually on the Navigating side, but as a Cadet I needed to spend time in the engine room so that I could at least appreciate the 50 degree heat and basic workings that went on down there.

Woke up one morning to eiry silence (you get used to the continued throbbing of the twin 25,000Hp engines that were fitted to the Osaka Bay - the ship I was on at the time). Somewhere mid ocean between Saudi and Sumatra we were adrift.

I spent the next 24 hours in a single solid shift helping the engineering officers and crew repair a broken piston ring.
The piston in question was about 2.5m wide and about 5 tall.

Don't remember much other servicing, but technology was pretty basic back then. Nothing digital and we didn't trust any analogue gauges so would take daily tank soundings by dropping a line into them and seeing where the wet bit got to...

 

[old_salt]

I was at the maritime college in the mid late 80's!

It was my induction course before heading to sea with the then P&O Containers Ltd.
I was actually on the Navigating side, but as a Cadet I needed to spend time in the engine room so that I could at least appreciate the 50 degree heat and basic workings that went on down there.

Woke up one morning to eiry silence (you get used to the continued throbbing of the twin 25,000Hp engines that were fitted to the Osaka Bay - the ship I was on at the time). Somewhere mid ocean between Saudi and Sumatra we were adrift.

I spent the next 24 hours in a single solid shift helping the engineering officers and crew repair a broken piston ring.
The piston in question was about 2.5m wide and about 5 tall.

Don't remember much other servicing, but technology was pretty basic back then. Nothing digital and we didn't trust any analogue gauges so would take daily tank soundings by dropping a line into them and seeing where the wet bit got to...

Yep that about sums it up.
Me 6 years Manchester Liners Engineer Steam.

 

[spannerman]

I have done this on a freighter once, we had to overhaul one of the 3 Volvo industrial engines driving generators in the engine room, two are always running and one is reserve, they got special dispensation to sail in coastal waterways without a reserve as this was the one being overhauled, but all 3 had to be functional to go out to sea. We went onboard at 8 in the morning in Stavanger and the ship was sailing up to Bergen, we had to be finished by then as then they were going direct to Aberdeen and could only go if all 3 were available so no pressure there then!
We had to remove the big ends and main bearings through 3 inspection holes in the side of the sump, pull out the pistons and liners and refit new liners, pistons, rings and bearings on the crank and 6 exchange heads!
Well we got down in the engine room and were greeted by the sight of the engine still coupled to its generator but hanging at an angle by chains so we could get to the under side of the engine, the down side it was the middle engine of 3 in a row and the other two were running at full chat just 2ft either side of the one we were going to be working on so everything was very warm to say the least. Then they fired up the 9 cyl inline main engine to get under way, the turbo was almost 3 ft in diameter and screamed like a jet engine, if you dropped a lump hammer on the steel decking you didn't hear it land, so we got some ear defenders but it was still like working right by a jet plane. it got warmer and warmer as the main engine got going, luckily the turbo pulled in huge amounts of fresh air through the ducts so we placed lots of bottles of coke in them to keep them cool as now everthing was around 40 degrees!
It was fine while we were in the fjord but when we got out to the coast the sea was running and this 1 1/2 ton engine/generator started swinging from side to side threatening to crush us against the 2 engines either side, so we stopped worked until they got some more chains and ratchets on it to hold it steady.
It was a long trip punctuated by several stops along the coast, we worked like monkeys for 18 hrs nonstop to get it finished, we had it running before we got into Bergen, the dour chief engineer couldn't believe we had done it so quickly and wouldn't sign it off, he was convinced we had left something out until we showed him all the old parts. I called for a taxi
to catch the fast catamaran back to Stavanger, so he reluctantly signed it off.
We got on the boat for the 4 hr trip home with our tools and promptly fell asleep, next thing we knew there was an almighty bang and the ferry spun through 90 degrees shaking madly, they went into neutral and the crew were running about looking over the stern, I told my mate if they ask if there are any mechanics onboard you keep your mouth shut, OK!
luckily there was no obvious damaged from whatever we had hit and we cruised into Stavanger.

Going back to servicing under way, the freighter had 3 centrifugal oil spinners to filter the oil on the main engine and the mechanic intermittently isolated one and opened the glass bowl on the top to clean out any dirt and then opened the taps to let oil pass through it again.
I could never work in a ships engine room, you never see anything, you don't know if its night or day or what the weather is, its always hot and noisy, but I admire those who can and do sail the world down in those hot hellholes.

 

[spinreach]

Yep that about sums it up.
Me 6 years Manchester Liners Engineer Steam.

Agree with that. Also during my cadet training (navigation side), I spent time in the engine room, usually whilst in the gulf or somewhere equally hot. Never when it was cold, funny that. Plenty of maintenance on generators, pumps, winches etc whilst at sea, but the serious stuff on the bigun was always kept for port, unless it went really wrong and we'd drift about until the necessary had been fixed.

I worked for Cunard, but then again, I still do!