While tripping merrily through the mail, Gregory Procter was overheard
 GP> Mixing of steam, diesel and electric power was often done in many
 GP> countries, although rarely all three at once! You forgot turbine power
 GP> by the way! The British tended to keep steam from electrified lines
 GP> because of the low mounted overhead wires and the perceived danger of
 GP> flash-over. 
It's packed away right now (I'm in the process of moving), but if your local
public library has a copy of Kalmbach's "The Hiawatha Story" there's some
nice photos of both and diesel and electric double-headed on the Milwaukee 
Road.
For a short time in 1949, the "Olympian Hiawatha" (Chicago to
the pacific Northwest) was pulled by Steam, Diesel AND Electric over 
the course of a single trip.
 GP> Steam locos could often start heavier trains than diesels or electrics
 GP> (comparing equivalent total weight on drive wheels) because diesels
 GP> and electrics are limited in the amount of current they can pass
 GP> through their axle motors from starting. A small steam shunter might
 GP> start twice the weight that an equivalent diesel electric shunter
 GP> could. 
 GP> Ok, I vote for steam :-)
Are you talking Diesel Electric or Diesel Hydraulic?
A Diesel-Electric can stand overloads for a short time.  As a general rule,
a Steam locomotive can PULL a train heavier than it can START (hence the
practice of backing up to take up the slack in the couplers, and then
essentially start the train one car at a time.)
A Diesel-Electric can START a train heavier than it can PULL (ever heard a 
diesel "winding up", getting a train moving, then backing off to let the 
traction motors cool, then starting the cycle all over again?).
It has to do with the "power curves" of the two types of locomotives.  A 
Steam locomotive developes it's maximum HP at "speed", while a Diesel has
a much "steeper" curve, and develope high horsepower at lower speeds.
Don
... My life is frittered away by detail.
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