Hi Gregory
On (11 Aug 97) Gregory Procter wrote to Alec Cameron...
 AC> Well, I don't know what you mean by steam MOTOR. Reciprocating
 GP> engine?
 AC> Cross compound? Vee 12? Turbine?
 GP> I'd stick with a reciprocating engine design, a; because it would need 
o
 GP> run
 GP> from zero RPM to xxxx RPM and b; because I don't know about turbines 
other
 GP> than turbos on car engines (and that's minimal)
 GP> First principal of the type would be simplicity and using currently
 GP> available
 GP> machinery for manufacture.
 GP> So; an in-line single acting motor with poppet valves. (and lower barrel
 GP> ports?)
I have had a lot to do with steam turbines but I never did see a steam engine
with in- line cylinders. I *suppose* that a conventional two cylinder steam
loco would have total cylinder volume of roughly 3000 cubic ins.
 GP>     Without getting out my slide-rule, 200mm bore and stroke per 
linder
I don't have a slide rule, but your 200mm cylinder would be about 400 cu ins,
so as a first approximation you have in mind a 6 or 8 cylinder steam engine.
Has there ever been such a thing? [I cannot see why not]. And if not, why
not??  Apart from the fact that for a given HP, engine costs of mfr and
maintenance increase with the number of cylinders used.
Maybe, that kind of engine was used on the large steam lorries that once
operated.
 GP> I found with the steam car design that a two speed gearbox made a major
 GP> difference to the engine design. 3 speeds didn't appear to be worth 
while.
Epicyclic with no clutch required, would probably be the choice.
 GP> At 515 KM/hr, any unsprung weight would count as heavy! An axle hung 
motor
 GP> would soon smooth out any uneveness in the track ;-)
Not so according to a paper I once saw. The writer was trying to show that in
a network having emu car sets of one uniform design, the rhythmic pounding of
axle hung motors would tend to synchronise with the local hill- and- dale
deterioration, making the hills higher and the dales lower, as each car set
traversed the worn sections. Writer said that this would tend to self-
correct, if assorted train carsets including loco hauled were instead used so
that no one carset design would prdominate.
        
 AC> See ya in the next message>>>>>>>>>.
Yes.
... I do most of my work sitting down; that's where I shine
--- PPoint 1.92
---------------