Re: starting a steam loco

In article <1191844429.195553.97320@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>,
Stephen Furley <furles@xxxxxxxxxxxxxxxxxx> wrote:
On 8 Oct, 12:21, a...@xxxxxxxxxx (Andrew Robert Breen) wrote:

In atmospheric engines, iirc, the weight of the pump rods descending was
used to start the engine - that pulled the piston up, steam was let in
behind it - and then the water sprays were put on to condense the steam
and create vacuum.

Yes, in the atmospheric engine the cylinder was constructed above the
boiler, and directly connected to it. The piston was normally at the
top of the cylinder, held there as you say by the weight of the pump
rods on the other end of the beam. Steam was allowed to rise from the
boiler into the cylinder, a valve was then closed, and water was
sprayed directly into the cylinder, thus condensing the steam, and
creating a vacuum below the piston, which was then pushed down by the
atmospheric pressure above it; there was, of course, no separate
condenser at that time. The water was then allowed out of the
cylinder, and air and steam let back in, so that the weight of the
pump rods pulled the piston back to the top of the cylinder, and the
cycle was repeated.

Nice illustration of the cycle at:

http://www.sciencemuseum.org.uk/on-line/energyhall/section3.asp

The Black Country Museum built a working replica of such an engine
some years ago, but the last I heard it was no longer in working
order. I don't know if it has since been repaired, or if there are
any plans to do so.

There's an engine at Eslecar, too - not working at present, but iirc there
are intentions..

Does the Science Museum ever run their atmospheric engine?

--
Andy Breen ~ Not speaking on behalf of the University of Wales, Aberystwyth
Feng Shui: an ancient oriental art for extracting
money from the gullible (Martin Sinclair)
.

Relevant Pages

  • Re: The Suzuki DF2.5 HP Has Arrived! (And the cooling system is working!)
    ... cylinder and rings and piston are bathed by pure oil and not some diluted ... I needed to drain the carburetor bowl, clean the fuel ... kind of work when the engine is not on the dinghy. ...
    (rec.boats.cruising)
  • Re: engine cylinder volume querry
    ... means a 1546cc engine is rated as 1600 cc engine, ... stroke with the good old geometry formula for the volume of a cylinder. ... of air that the piston in one cylinder pushes out or displaces in one ...
    (rec.autos.tech)
  • Re: starting a steam loco
    ... engine, but I would query the statement, "Steam was allowed to rise from ... the boiler into the cylinder". ... over the boiler, so it would contain a mixture of air and steam. ...
    (uk.railway)
  • Re: Flywheels.....
    ... Steam locomotives put out maximum torque when they start at zero RPM. ... Unlike internal-combustion engines, high-pressure steam piston engines ... the pressure can rise inside ... With a gas piston engine, ...
    (rec.bicycles.tech)
  • Re: (OT) Hey AoGLP...
    ... It's a vertical three cylinder steam engine and is about the size of a small house. ... That funding problem IS why they have the engine in the first place tho as the group who was trying to save the entire ship did in fact drain their coffers. ...
    (rec.sport.pro-wrestling)