-=> Quoting Alec Cameron to Gregory Procter <=-
Continued:
 GP>       to haulage bogies as yet.
 GP>       I don't know of any railway that mounts its couplers at rail 
height,
 AC> NSW Railways headed in that direction, with Co Co electrics of 3780 HP
 AC> [1953]. These had the bogies coupled together, the drawgear on the
 AC> bogies' ends. The body was a lightweight "shell" as it had no buffing
 AC> loads to carry. One bogie was pinned to the body [king pin] and the
 AC> other bogie had a slider. So when cornering on tight radii, one end of
 AC> the body would stay above the track locus, but the other end of the
 AC> body would pitch toward the lateral limit of the loading gauge.
Now THATS a compromise!
 GP>  No, I was thinking along the lines of a Diesel Hydraulic chassis, ie
 GP> bogies
 GP>  driven by cardan shafts and gearing, with a high speed steam motor
 GP> in the
 AC> Maybe your next message will say- steam motor? Turbine or what?
 AC> ^^^^^^^^^^^
 GP>       I'm not sure of your point here?
 AC> Well, I don't know what you mean by steam MOTOR. Reciprocating engine?
 AC> Cross compound? Vee 12? Turbine?
I've designed or redesigned several I/C motors, but I've never even worked on
a steamer. I did do some initial design work once on a steamcar, just playing
around with concepts.
I'd stick with a reciprocating engine design, a; because it would need to run
from zero RPM to xxxx RPM and b; because I don't know about turbines other
than turbos on car engines (and that's minimal)
First principal of the type would be simplicity and using currently available
machinery for manufacture.
So; an in-line single acting motor with poppet valves. (and lower barrel 
ports?)
    Piston speed would be a limiting factor, 2500 feet per minute as an upper
    limit.
    Electronically operated poppet valves would be practical.
    Without getting out my slide-rule, 200mm bore and stroke per cylinder at
    about 3800 Rpm should be practical. (circa 800 ft/lbs torque)
    Multiply cylinders until required torque achieved.
I found with the steam car design that a two speed gearbox made a major
difference to the engine design. 3 speeds didn't appear to be worth while.
 GP>       Cardan shafts are commonly used on Diesels and Electrics (Europe) 
to
 GP>       reduce the unsprung weight on wheelsets. eg TGVs have the electric
 GP> motor
 GP>       on the mainframe driving each axle by cardan shafts.
 AC> A great solution, if the traction motor is huge and heavy.
At 515 KM/hr, any unsprung weight would count as heavy! An axle hung motor
would soon smooth out any uneveness in the track ;-)
 AC> See ya in the next message>>>>>>>>>.
 AC> ...
 AC> -!- PPoint 1.92
 AC>  ! Origin: Bundanoon, Southern Highlands, NSW AUS (3:712/517.12)
  
... Catch the Blue Wave!
--- FMail 1.02
---------------