# Triple expansion engines.



## jamesgpobog

I have no experience with them at all. I found this very simplified animation on the John W. Brown website...

http://www.liberty-ship.com/html/vtour/images/steamengineanimation.gif

I hadn't realized that the pistons were acted on in each direction. Now, my question is because what my brain is telling me doesn't match what I see in the diagram, but it's probably because of lack of detail.

Am I correct in assuming that the exhaust from each cylinder, from each direction, is valved into a manifold that then becomes the intake (for both directions) for the next cylinder?


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## Mikepg

The exhaust from the high pressure cylinder exhausted into the steam chest of the medium pressure cylinder and that from there exhausted into the steam chest of the low pressure cylinder. Each cylinder had it's own valve gear to distribute the total steam from the previous source, normally. Apart from toys like 'Mamods', most steam reciprocating engines were 'double acting', and there were even some double acting marine diesels. A double expansion steam engine is normally refered to as a 'compound'.
Regards, Mike


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## Long gone

Looking at that diagram, were all the valves slide valves or did the h.p. cylinder have a piston valve?

Another thing that intrigues me. What would happen if the h.p. cylinder stopped on 'dead centre', or the h.p. valve was 'blind'?


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## chadburn

Act on an impulse.(Thumb)


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## Ron Dean

Long gone said:


> Another thing that intrigues me. What would happen if the h.p. cylinder stopped on 'dead centre', or the h.p. valve was 'blind'?


I'm not sure there will ever be a "dead centre". I suspect there will be a small degree of overlap on the various ports, in which case the highest pressure will always take over in the direction of rotation. Just my thoughts - I don't know for sure.

Ron.


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## jamesgpobog

Ron Dean said:


> I'm not sure there will ever be a "dead centre". I suspect there will be a small degree of overlap on the various ports, in which case the highest pressure will always take over in the direction of rotation. Just my thoughts - I don't know for sure.
> 
> Ron.


That makes sense to me. I know that in automotive gasoline engines there is always some valve overlap that can be played with to give different performance qualities...


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## John Paul

*Impulse valves*

Manually operated valves could be used to admit live steam to the IP or LP cylinders to give the required impulse to get the HP off a dead centre,from memory these could act on the top or bottom of the cylinders depending if going astern or ahead.


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## jamesgpobog

John Paul said:


> Manually operated valves could be used to admit live steam to the IP or LP cylinders to give the required impulse to get the HP off a dead centre,from memory these could act on the top or bottom of the cylinders depending if going astern or ahead.


Damn, that makes sense too. Sure would give a solid 'baseline' for any kind of valve timing 'tuning' to be done...


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## John Paul

I recall setting valves on a triple expansion when serving my time,Piston valves were done with sticks and flat v/vs with feelers to measure port opening top and bottom Revering gear was placed at full over ahead so eccentric rod was inline with v/v rod. and the engine bared over to TDC or BDC. Once FAOP indicator cards would be taken and horsepower calulated, to balance up power the links were adjusted in or out..Impulse valves also known as starting valves


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## Varley

Father (as 'Plump Plumber' of 13th, I think, ML flottila) visited a merchantman in (again 'think') Gibraltar. Chief had brass template for the indicator cards he returned to HO - actuality of this detail was not HO's business! Never heard a hint of this in my time.


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## david freeman

Some where in my distant past Auxilary steam pumps and fans etc, had no lap or lead, and therefore steam was admitted for the whole stroke-Unless you had a weirs pump wiyth the shuttle valve, then there was a small lap and lead, and one had a spaneer if the steam valvle become stuck or the steam pressure reduced being insufficient to power the piston stroke.
On a main Triple expansion engine main engine or a Bellis and Morcom Steam deriven genny engine the piston of 'D' valves had lap and lead and so live steam was not admiitted for 100% of the stroke, it expanded as the stroke progessed and did work. On a main Recip Marine engine one had some short of valve gear where one could adjust the position of the valve movement, so making the steam wok harder and more efficiently.


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## Long gone

John Paul said:


> Manually operated valves could be used to admit live steam to the IP or LP cylinders to give the required impulse to get the HP off a dead centre,from memory these could act on the top or bottom of the cylinders depending if going astern or ahead.


That confirms my thinking; it sounds a similar system to that used by the Smith-Johnson Midland Compounds, where a valve admitted steam at 85% of boiler pressure to the l.p. receiver, to aid starting. They had 1 h.p. and 2 l.p. cylinders


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## chadburn

John Paul said:


> Manually operated valves could be used to admit live steam to the IP or LP cylinders to give the required impulse to get the HP off a dead centre,from memory these could act on the top or bottom of the cylinders depending if going astern or ahead.


As I indicated John, "act on an Impulse", just for further information for those who may not know, impulse steam is usually at reduced main steam pressure and is injected straight into the desired cylinder bypassing the valves and as indicted by John depending on direction. It can also be used to give the engine a bit of a "boost" if done correctly. Long leggers are a double acting gas engine's.


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## Ron Dean

chadburn said:


> As I indicated John, "act on an Impulse", just for further information for those who may not know, impulse steam is usually at reduced main steam pressure and is injected straight into the desired cylinder bypassing the valves and as indicted by John depending on direction. It can also be used to give the engine a bit of a "boost" if done correctly. Long leggers are a double acting gas engine's.


Somewhat akin to getting a compression ignition engine started with compressed air, to get the beast turning.


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## jim garnett

My memory may not be too good as it is 60 years since I served on

a triple expansion engine.I believe if it was stuck on tdc we only had to give the reversing gear engine a bit of a nudge and thus alter the valve position.As regards lap and lead the steam steering gear did not have any for obvious reasons.
Many triple expansion engines were fitted with exhaust turbines.
As I found out you never routed the steam winch exhaust steam to the main condenser while underway.It makes a VERY large knocking noise in the L p cylinder.
JIM GARNETT


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## murrayis

On a triple expansion steam tug I used to crew, we had the occasional stop on TDC. It always seemed to happen just when those pesky wharfs jump out in front of you (or some other solid object) and you’re trying to go from full ahead to full astern. You could hear the engine stop, then a lot of technical words coming up from the fiddley as the engineer rocked the reversing gear back and forth until finally she would kick. In reality it was probably a matter of seconds but it seemed like an eternity.[=P]


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## teop

Hi,
yes a special lever/handle for impulse steam to kick the stuburrn hp crank.
Near by, facinating with linkage set, a triple, cranks bouncing from one side to another without rotating during warming up.
regards
teop


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## chadburn

Absolutely right Teop, most Engineer's would not only use this method for warming up but also between telegraph order's, when stop was requested they would bounce the crank's to prevent a possible jam up until the next "request" from the Bridge when approaching or going alongside.


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## jim garnett

When was the last commercial triple expansion vessel built.I went on board a brand new triple expansion vessel with an exhaust turbine.after the lp cylinder.It was on it's maiden voyage in 1953 when I visited it in San Pedro de Macoris WI.It was one of Hogarths and had three oil fired scotch boilers.The chief was very proud of her.I'm not sure why.
Jim Garnett


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## Basil

When you think about it, a triple has the same number of power strokes per revolution that a 12 cyl car engine would have. Smooth!


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## chadburn

When I started at Smiths the last triple with LP Turbine was being built there in 1955 my initial's were/are popped on the bedplate, she was called the "Tynemouth". My first MN vessel was Hogarth's "Baron Ardrossan" she was also a Triple with an LP turbine and built in 1954. VTE's of all size's were a joy to operate and work on it's just the Boiler's that were a bally nightmare on occasion's.. They appear to have stopped building VTE's about the mid 1950's---------unless someone knows different of course!!!!!!


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## Duncan112

The Bosporus ferries were built at Fairfields with Triple Expansion Engines in 1961, and remained in service until the late 1990s/early 2000s.


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## gordy

http://pspsscotland.blogspot.com/2010/01/httpwwwclydesitecoukclydebuiltviewshipa.html


Above site states not all the Turkish Ferries had Clyde built engines.
I started my time in June 1961 and the fitting out basin with the 9 ferries in there was spectacular.


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## Duncan112

Thanks for the link Gordy, film clip is spectacular!! 

Have you any photos of the fitting out basin?


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## chadburn

Good posting Gordy, they must be the last of the engine build, I wonder how many Engineer's on this Site were on VTE's, I thought that they were a great engine and it's little wonder that Shipowner's stuck with them for so long. It was the Doxford engine that brought about their demise. Although the initial build cost for a Diesel engined vessel was high the fuel usage was around 11tns per day at sea whereas the old steam job was around 34tns per day.


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## woodend

I have just shaken the dust off my copy of the 'Self Examiner for Masters and Mates (All Grades) revised edition 1957 and the first question in the Main Engines Section, Steam Reciprocating Engines is 'Describe a triple expansion engine?'. Oh how much I have forgotten!!!


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## gordy

Duncan112 said:


> Thanks for the link Gordy, film clip is spectacular!!
> 
> Have you any photos of the fitting out basin?


Here's *one* courtesy of Bobby


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## Scotch Boiler

Thanks, Gordy, great film particularly of the engine room. I noted that the engines were closed crankcase. When I started on the tugs in 1976 at the Auckland Harbour Board there were still two steam tugs, both with open crankcases. The oldest was the coal-fired William C Daldy 1936, and the oil-fired Aucklander. Daldy was built at Simon & Lobnitz, Paisley, and the Aucklander was built at Fleming & Ferguson,Renfrew. They were laid up in 1977 and 1985 respectively.
Great jobs while they lasted. Three engineers and two firemen among a total crew of ten.


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## Peter Short

Scotch Boiler said:


> there were still two steam tugs, both with open crankcases. The oldest was the coal-fired William C Daldy 1936, and the oil-fired Aucklander.


 
Scotch Boiler,

I seem to recall the Aucklander had enclosed crankcases? I might be wrong, but it was a very modern vessel, Scotsmen had to be dragged out of retirement homes to build her triples (LOL)

The Daldy still takes trips and is one of the great undiscovered steam experiences in NZ. Passengers can go below and wander around the engines and boilers, there is no safety talk, just make yourself at home and do what you like, put your head under a cross head if you like. So...while all the other passengers are on deck taking in the sights, I was the only person on two occasions, wandering around two running open triples, steam generators, many steam pumps, steam steering engine of most unusual design etc, through to the boilers, etc.


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## Bob_F

Peter Short said:


> Scotch Boiler,
> 
> I seem to recall the Aucklander had enclosed crankcases? I might be wrong, but it was a very modern vessel, Scotsmen had to be dragged out of retirement homes to build her triples (LOL)
> 
> The Daldy still takes trips and is one of the great undiscovered steam experiences in NZ. Passengers can go below and wander around the engines and boilers, there is no safety talk, just make yourself at home and do what you like, put your head under a cross head if you like. So...while all the other passengers are on deck taking in the sights, I was the only person on two occasions, wandering around two running open triples, steam generators, many steam pumps, steam steering engine of most unusual design etc, through to the boilers, etc.


It could have been a enclosed crankcase as Lobnitz built a trple expansion like this. Installed one on the RFA tanker Eddycliff.


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## 5036

What is missing is the wonderful smell of a steam engine room. Here are a couple of excellent videos of PS Waverley's engines and paddle crank shaft working, this is art and engineering. If you get a chance, go on her as said above the engines are so smooth, it is like the ship accelerates on rails. She sails around the south coast of England in the early and late summer and spends the rest of the time in Scotland. 

http://www.youtube.com/watch?v=fhUr_bC74mU&feature=related

http://www.youtube.com/watch?v=W6EbJudRiYQ


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## 5036

Peter Short said:


> Scotch Boiler,
> 
> I seem to recall the Aucklander had enclosed crankcases? I might be wrong, but it was a very modern vessel, Scotsmen had to be dragged out of retirement homes to build her triples (LOL)
> 
> The story goes that a yard manager went into a pub in Greenock to see if any of the old boys could be found and hired. A local worthy told him he would find most of them at 1 South Street and the manager excitedly set off to find that the address is Greenock Cemetery.


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## chadburn

There are some of us around who can still remember the proceedure of how to draw file the reversing link's to make them parallel.


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## Ian J. Huckin

Not sure if this is completely off-topic but earlier in this thread there was a question about steam engines having automobile type valves...in answer, and appropriately, the re-built Merchant Navy class Pacifics that generally ran the old Southern Region metal had chain driven "poppet valves" all in an enclosed oil bath. Theses locos (35?) generally ran just under a million miles in their career's and valve failure was not an issue at all. These locos also had the largest tractive effort of any of the SR machines.


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## Duncan112

I think the chain driven valve gear, designed by Oliver Bulleid was removed at the rebuilding and replaced with conventional Walschaerts type. 

There is a drawing of the original Bulleid gear here http://upload.wikimedia.org/wikipedia/commons/b/b6/Bulleid_chain_valve_gear.svg

Again the valves, certainly on the rebuilt engines were piston type, BUT the Duke of Gloucester, currently on the East Lancashire Railway has Caprotti type poppet valves which produce a very distinctive sound.

It is a pity that the 5AT project has been shelved as we would have seen a modern steam engine, as it is we will have to hope that the A1 Steam Locomotive Trust are successful with their intent to build a 2-8-2 Mikado to modern standards


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## Ian J. Huckin

Duncan112 said:


> I think the chain driven valve gear, designed by Oliver Bulleid was removed at the rebuilding and replaced with conventional Walschaerts type.
> 
> There is a drawing of the original Bulleid gear here http://upload.wikimedia.org/wikipedia/commons/b/b6/Bulleid_chain_valve_gear.svg
> 
> Again the valves, certainly on the rebuilt engines were piston type, BUT the Duke of Gloucester, currently on the East Lancashire Railway has Caprotti type poppet valves which produce a very distinctive sound.
> 
> It is a pity that the 5AT project has been shelved as we would have seen a modern steam engine, as it is we will have to hope that the A1 Steam Locomotive Trust are successful with their intent to build a 2-8-2 Mikado to modern standards


Yes, you are right of course, the "flat top" version did not have the Walschaerts valve gear. I have a beautiful book about the MN locos, detailed maintenance history of each one etc and I knew I should have re-read it first...drat!!!!!


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## Derek Roger

Anybody know anything about Open and Crossed links ( re recip steam engines ) ??


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## howardws

Duncan112 said:


> I think the chain driven valve gear, designed by Oliver Bulleid was removed at the rebuilding and replaced with conventional Walschaerts type.
> 
> There is a drawing of the original Bulleid gear here http://upload.wikimedia.org/wikipedia/commons/b/b6/Bulleid_chain_valve_gear.svg
> 
> Again the valves, certainly on the rebuilt engines were piston type, BUT the Duke of Gloucester, currently on the East Lancashire Railway has Caprotti type poppet valves which produce a very distinctive sound.
> 
> It is a pity that the 5AT project has been shelved as we would have seen a modern steam engine, as it is we will have to hope that the A1 Steam Locomotive Trust are successful with their intent to build a 2-8-2 Mikado to modern standards


I think you will find that the Bulleid pacifics were always piston valve engines. When they were rebuilt with Walschaerts valve gear they were changed from inside to outside admission.


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## Ian J. Huckin

howardws said:


> I think you will find that the Bulleid pacifics were always piston valve engines. When they were rebuilt with Walschaerts valve gear they were changed from inside to outside admission.


I'll get the book out this evening for the deffinative answer. If you search "Merchant Navy" on eBay this book comes up now and again. It costs nearly $100 with shipping but it is a monster yarn....


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## Scotch Boiler

nav said:


> Peter Short said:
> 
> 
> 
> Scotch Boiler,
> 
> I seem to recall the Aucklander had enclosed crankcases? I might be wrong, but it was a very modern vessel, Scotsmen had to be dragged out of retirement homes to build her triples (LOL)
> 
> The story goes that a yard manager went into a pub in Greenock to see if any of the old boys could be found and hired. A local worthy told him he would find most of them at 1 South Street and the manager excitedly set off to find that the address is Greenock Cemetery.
> 
> 
> 
> I went back to my notes to get the stats for the "Aucklander": built 1957 at Fleming & Ferguson, Paisley. Job No. 784. Displacement tonnage 852 tons. Bollard pull 28 tons. Two oil-fired scotch boilers from Barclay Curle, Glasgow supplying steam at 200 psi to two triple expansion engines of 1,800 ihp at 145 rpm built by Fleming Ferguson.
> The story goes that when the old chief from the coal burner Wm C Daldy was consulted by the board members of the Auckland Harbour Board about the design, he said stick with steam engines but consider oil firing. The chief of course only had a steam ticket so he wasn't going to recommend anything else or new fangled like a motor tug.
> It may well have been the last steam tug built in the UK. It definitely had open crankcases. I had my arms in there oiling the crossheads, you tipped in about a litre every hour.
Click to expand...


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## Scotch Boiler

nav said:


> Peter Short said:
> 
> 
> 
> Scotch Boiler,
> 
> I seem to recall the Aucklander had enclosed crankcases? I might be wrong, but it was a very modern vessel, Scotsmen had to be dragged out of retirement homes to build her triples (LOL)
> 
> The story goes that a yard manager went into a pub in Greenock to see if any of the old boys could be found and hired. A local worthy told him he would find most of them at 1 South Street and the manager excitedly set off to find that the address is Greenock Cemetery.
> 
> 
> 
> 
> Hi Nav, you sound like a Clydesider. Only a Greenockian would know that 1 South St was the Greenock cemetry. Lang may yer lum reek.
> 
> 
> 
> 
> 
> .
Click to expand...


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## 5036

Scotch Boiler said:


> nav said:
> 
> 
> 
> Hi Nav, you sound like a Clydesider. Only a Greenockian would know that 1 South St was the Greenock cemetry. Lang may yer lum reek.
> 
> .
> 
> 
> 
> Born and bred!
Click to expand...


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## John Paul

Caprotti valve gear on triple expansions engines.

the St Denys ex Northgate Scott of Falmouth Towage had a triple build by Beardmore fitted with Caprotti valve gear. The gear box was located port side behind cylinders i never saw inside the box but was assured it was a work of art. (Uncle was c/e) Recollect that she was very quite and had all round reversing gear, a real treat to see working. she is now preserved in France.


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## chadburn

Derek Roger said:


> Anybody know anything about Open and Crossed links ( re recip steam engines ) ??


Not sure what answer you are after Derek, the Link's I am familiar with are the well known Stephenson Link's and the lesser known Joy's. The advantage of the Joy's valve gear was that the valve could be placed on the side of the cylinder rather than between them as in the Stephenson's, which made for a shorter length engine.


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## Long gone

I remember reading about open and crossed links in a book about steam loco. running by, inevitably, O.S. Nock. Now I forget exactly what he said (can't immediately lay my hands on the book), but I believe that, as link motion is 'notched up' to allow for more expansive working, the lead of the valve decreases. This is cited as an advantage over Walscheart's valve gear, and is for when the links are arranged normally, or 'open'. When the links are crossed, the opposite occurs, i.e. the valve lead increases. Apparently this has a deleterious effect on the running and economy of the loco.


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