Steamship Construction

[The Old Ruminator]

A while back I stuck on some stuff for engines etc then deleted it by mistake. As a relief from wreck notes I thought from time to time I would build this post on steamships in general.In the wreck notes themselves if something techy crops up we can refer back here for enlightenment.
The Compound Engine.
Fitted to steamships up to the 1890's when they were superceded by the more economical triple expansion engine. The compound normally has 2 cylinders, a high pressure nearest the boiler and a low pressure. It is possible to look at the size of an engine and guess the size of a ship. The number of boilers also helps in this respect. Compound engines were very rugged and often saw service for 50 years or more. They were hardly ever replaced in a ship with a triple expansion engine as the shipowner would lose cargo space. Prior to WW2 nearly every ship engine was unique. Each engine was built for each individual ship. The set of cylinder sizes found in Lloyds Register are another useful way to idenify a ship. ( See Aeneas ).

[The Old Ruminator]

With the introduction of higher pressure boilers and better condenser design it was possible to expand the steam 3 times. ( and eventually 4 times ). This engine is known as a triple expansion engine. It will have low , medium and high pressure cylinders. There could be 2 cylinders of the same size giving a four cylinder Trip. Exp. engine. These three cylinder engines are the most likely ones you will see on a wreck. The condenser changed the steam back to water but more important for efficiancy it reduced the back pressure on the engine.Each one will still be unique to the ship and remember the little cylinder is nearest the boiler and ships bow.Useful if you are looking for the bell.The wheel on the engine is a reversing wheel. Wrecks that have the engine broken open so you can see the piston are Baygitano, Moidart and Aeneas.

For a complete explanation of steamship engines see =
Steam at Sea by Denis Griffiths ISBN 0 85177 666 3

[The Old Ruminator]

Will just keep this as one long thread. Will mostly be photos . Lets hope Photobucket stays alive for a good few years.

Standard Trip Exp Engine



Starting to get more complex.



Approaching the ultimate in design and scale. Eventually steam engines reached the end of practical development employing superheaters and auxillary turbines.Indeed even in Victorian times it was proved by "Turbinia" that steam turbines would eventually succeed reciprocating engines.



The condenser set up.

[Razorbill]

I`m lovin` it Nick.
Keep it up.

[The Old Ruminator]

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[The Old Ruminator]

Right Razorbill you asked for it. Never mind the doors I am going to blow your bloody socks off.

These and the other superb drawings are from the classic work "Illustrated Marine Encyclopedia" published in 1890 by Capt. H. Paasch a Belgian marine surveyor. My rebound copy cost me £70 some years ago.

[martin58]

I originally posted these pics a while ago on another thread but thought they may be of more interest here given the excellent info on ships engine rooms etc. Here are a few pictures taken in the engine room of the SS Thorfinn which was originally constructed in the Stord Shipyards, Norway, 1954 - as Ice Class Antarctic whaler. She was converted to a cruise/ charter ship in the early 70’s. The Main Engine is a FMV Double compound steam reciprocating - 2,500 h.p. @ 140 rpm. The Boilers are Foster Wheeler Corp (2 x 18,000 lbs./hr each @ 250 psi working press. 600 deg F superheat). The ship uses 2 x Detroit Diesel Generators- Model 6-71N, 100KW, 440 VAC, 3 phase each.

[neilh]

I don't suppose anyone has more pictures/photos of donkey boilers or domes do they? There was something lying next to a boiler on a wreck we dived today and I'd love to know what it is!

Also were donkey boilers particular to certain types of vessel or could they be found on pretty much anything?

[The Old Ruminator]

Will have a look neil.

Donkey boilers were used mostly on cargo vessels to power machinery , particularly winches , when the ship was in port . Sometimes the donkey boiler wasnt fitted in the engine room but was sited abaft the funnel on the upper deck. With the disintegration of a wreck the donkey boiler often falls down into the remains of the engine room. You then get the impression that it is where it belongs. The usual donkey boiler was a cylinder in an upright position with the grating on the side.

[The Old Ruminator]

[The Old Ruminator]

Deck mounted horizontal donkey boiler.





Scotch type boiler room installed donkey boiler.





It does appear that with more modern and larger ships the favoured position for the donkey boiler was in the boiler room.

[neilh]

Originally Posted by salsettediving

Donkey boilers were used mostly on cargo vessels to power machinery , particularly winches , when the ship was in port . Sometimes the donkey boiler wasnt fitted in the engine room but was sited abaft the funnel on the upper deck. With the disintegration of a wreck the donkey boiler often falls down into the remains of the engine room. You then get the impression that it is where it belongs. The usual donkey boiler was a cylinder in an upright position with the grating on the side.

It looked slightly out of place lying right next to the boiler with no obvious connection, but then there was also a lot of trawl nets over the wreck so we figured there was also a possibility of it having been dragged there.

I was looking at your pictures last night and it was illustration "C" that got me wondering whether it was a donkey boiler as it bears some similarities.

I've got some stills from the video but don't want to litter a really useful thread with random pictures that may or may not have anything to do with the topic! I'll start a separate thread