# Pressurised stokeholds



## TurboTyne (Aug 30, 2012)

Did many merchant ships have pressurised stokeholds? I had thought that these were only found in RN ships, but I’ve just read that 4 steamers (TSS Manxman, TSS Londonderry, SS Antrim and SS Donegal) built about 1904 all had such stokeholds, with pressurization at 1.1 and 1.5”. I wonder how this compares to pressures in RN ships and if this type of stokehold was generally disliked by the stokers and engineers? 
Thanks for any info.
Mike


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## billmaca (Jan 14, 2006)

The old Queens had them ,They were a bit awkward when the watertight doors were down and you had to get through the double pressure doors when carrying something.


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## TurboTyne (Aug 30, 2012)

Thanks for the response Billmaca. Could you please explain a little about how one went from the stokehold to a non-pressurised compartment or vice versa? 

e.g. Was there a risk of accidents when opening and closing the doors and were there set procedures that had to be followed to avoid injury and/or damage ? 

Thanks, Mike


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## A.D.FROST (Sep 1, 2008)

mvSOUTHLAND & WELLINGTON STARS (BSL) (no sky light)had pressurised ER (helps the T/C) Changing room acted as a air lock.Sailed on one ship when some-one had closed the fwd.vent flaps (Fans started up auto) pressurised the space,when the WT door was opened the door hit him in the face.


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## chadburn (Jun 2, 2008)

The American's were quite keen on pressurised Stokehold's following their Navy Warship type and were installed on the "American Legion Class" of Passenger Vessel's. The Burner's were of the mechanical Navy type and as indicated the pressurised stokehold's were found to be very uncomfortable to a point where the installation was changed to natural draught with the burner's being changed to Dahl's. This change meant that the vessel( President Pierce) was able to make full power on natural draught along with a more comfortable working condition's


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## Varley (Oct 1, 2006)

Pardon me for speaking out of discipline but I would have thought boiler plant without any of originally designed in; pressurised stokehold, FD or ID would have a much reduced power to weight(or space) ratio (ie if same boilers nothing like the same throughput).

Didn't Stephenson require an ID steam ejector ("Blast Pipe") to maintain Rocket as anything more than a Georgian Teasmade on wheels?


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## Long gone (Jun 20, 2009)

No, returning the exhaust to the chimney via a blastpipe was Timothy Hackworth's idea. *Robert* Stephenson's idea, or a least someone at his works, was the multitubular boiler


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## Varley (Oct 1, 2006)

Long gone said:


> No, returning the exhaust to the chimney via a blastpipe was Timothy Hackworth's idea. *Robert* Stephenson's idea, or a least someone at his works, was the multitubular boiler


Thanks for that. I saw there was some debate as to whether Stephenson had borrowed the idea from someone else.

I still doubt that Rocket's boiler would have performed without it (the case in point was for a system where the burners only had been changed - so for the same area of heat exchanger and less oxygen I cannot see what variable, except substantially higher calorific value fuel - my chemistry is not good enough to know if that could be done without more oxygen anyway - could have been upped to maintain anything like the same performance).

(I now see that, earlier still, Trevithick, exhausting up the chimney for convenience had 'noticed' the effect, I don't remember Hackworth getting any mention in my youth although 'his' locomotives I do remember and have seen Locomotion II in action at Beamish - does he have one at the South Ken. Science Museum? Was there last year, terribly disappointed. I regret it but they should charge and turn it back into one - as they should the Maritime Museum at Greenwich).


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## spongebob (Dec 11, 2007)

I recall engine trials after refit aboard HMNZS Black Prince, a Dido class light cruiser. Enter a boiler room while maximum steaming at about 32 knots and the pressure change after going through the airlock doors was like a sledgehammer to the ears. Only a few inches water gauge but a shock to the human body.

Bob(Hippy)


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## billmaca (Jan 14, 2006)

The double doors on the old Queens worked like a small airlock, when you operated the handles to open the door, plates with holes in them attached to the handles lined up with holes in the door ,letting pressure equalize with the inside of the chamber, you stepped inside closed the door and then did the same with the other door,when the watertight doors were in operation that ment you had to work one of the doors and the watertight door at the same time, if both doors were opened by accident you got a gale of wind, loss of pressure, and some fun with the fires,


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## eldersuk (Oct 24, 2005)

It happened on an ED's ship down the Coast.
One morning at breakfast our beloved OM saw* a* fly in the saloon (remember we are in West Africa) and so instructed Chippy to block up the vents in the saloon doors.
Now the public rooms and cabins were air conditioned, the alleyways were not. The result was a build up of positive pressure in the saloon.
Guess what happened when a steward carrying a tray of plates of soup opened the saloon doors.
Again, the law of unintended consequences.

Derek


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## billyboy (Jul 6, 2005)

SS Brighton had an air lock between engine room and Boiler room.
As long as the pressure was equalized slowly there was no problem.
Equalize too quickly and the ear drums would pop. Both doors had a window panel so you could make sure no body was opening the other door at the same time.


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## TurboTyne (Aug 30, 2012)

billmaca said:


> ,when the watertight doors were in operation that ment you had to work one of the doors and the watertight door at the same time,


Where were the watertight doors Billmaca? 
In the middle of the air lock? one each side? Also how did they operate and were they closed all time at sea or just under special cir***stances?

I was once told (by an ex-RN tiffy) that pressurised stokeholds were not popular in merchant ships because of the feeling of being trapped, claustrophobia etc. Thanks, Mike


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## billmaca (Jan 14, 2006)

The watertight doors were on the outside of one of the airlock doors, they were operated by a lever ,pull the lever to lift, the snag being that as soon as you let go the lever they started down again,with a warning bell ringing, therefor you had to hold the lever on, open the lock door with the other hand let go and nip through into the chamber.I forgot to mention about the glass panels but Billyboy has put you right on them


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## TurboTyne (Aug 30, 2012)

Thanks Billmaca. Were the water-tight doors always kept closed whilst at sea or only under special conditions?
Mike


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## billmaca (Jan 14, 2006)

Only when in fog or there was an ice warning+fire drills, as far as I can remember


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## engineer64 (Jan 21, 2013)

In warships with pressurised boiler rooms, we had two types of Admiralty three drum boilers. One type, open front furnaces, the pressurised air entered the furnace through the front . The other type closed front the air was ducted through trunking from the back of the boiler picking up pre-heat, to the front of the furnace into the sprayer register. I speak of warships built during the war & shortly afterwards.


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## R58484956 (Apr 19, 2004)

On the QE(1) the airlocks had a triangular plate fitted on the bulkhead, when I took Liberace on a tour of "down below" someone had put a candlelabria on the shelf made of wax sticks (for finding vacuum leaks) and he was so pleased he invited the whole watch to have drinks on him later that evening in the Pig & Whistle.


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## fwalkden (Mar 27, 2008)

The IOMSP ss Ben My Chree also had a pressurised boiler room. Double ended Scotch boilers if memory serves. Very comfortable temperatures in summer but extremely chilly in winter!


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