Actually, I read somewhere that the US Navy is converting its steam
catapults to linear electric motors to get finer control over the launch. I
also suspect that it reduces the manpower required to operate the "cat".

Bill Daniels

"Bob Johnson" wrote in message
...
Hi Bruce --

That's a very welcome correction to my hazily-remembered version of a
second-hand report of what the 454 c.i. engine torque/hp/rpm chart looks
like. This is the kind of info I was looking for and thanks for providing
it!

In all our past kicking around of the ideal winch prime mover, here's one
that sounds silly but might rate at least an engineering investigation --
a
recip steam engine! If I recall correctly, the steam engine develops max
torque at stall.

What got me thinking about that was the fact that the Navy gets 66,000 lb
Super Hornets flying in about the same three seconds that it takes us to
get
airborne. And they do it with steam, not because it's handy, but that's
probably the only practical way to get it done.

BJ

Bruce Hoult wrote:

In article ,
Bob Johnson wrote:

Our engine is petrol fueled. Despite Google's best efforts, I have not
yet located a Torque/HP/RPM curve for our very common 7.4 L engine,
but
have heard that it develops max torque and HP at about 3000 RPM and
further that the curves are fairly flat at this point.

You are making some totally contradictory and inconsistent claims there.

If max torque and max HP occur close together then they must both drop
off precipitously after that.

If the torque curve is flat then HP will be increasing linearly with
RPM, max torque and max HP will be very far apart.

It is quite likely that you do have maximum torque at around 3000 RPM,
but if for example the torque curve is flat enough that the torque at
the 5000 RPM redline is still 60% or more of that at 3000 RPM then that
(redline) is exactly where maximum power will be.

-- Bruce