Re: Thought exercise - steam VFT

[dbromage@fang.omni.com.au (David Bromage)]

William Pearce (ben_issacs@optusnet.com.au) wrote:
>     In re Dave Bromage's High Speed Steam Train exercise, firstly one must
> think about the herbs that would be required to run such a train. I had some
> info on calculating horse powers required at various speeds, but cannot find
> it, however, using figures for a Shinkansen set running at 270 km/h (about
> 180 mph), it seems that one requires about 30 hp/ton of train to attain that
> speed. Assuming ten 50 ton SOP type cars, plus say 250 tons for the
> locomotive, we get a total train weight of 750 tons,

The train wouldn't be that heavy. I was working on a load of 5 double deck
cars of about 50t each.

> multiplying this figure
> by 30 gives us a horse power of 22,500! I think that the most powerful steam
> loco of that era gave about 7,000 hp. (Challenger or Big Boy?)

PRR T1 could also generate 7000hp, and was unofficially credited with
140mph.

>   That amount of power would require a lot of steam, therefore a lot of
> water, too much to haul in a tender,

Hence the placement of water troughs every 60 miles.

>   As for fuel, coal is impossible, for the horse power required a grate area
> of about 350 or so square feet area would be needed,

It can be done with 202 ft2, which means about 52t of coal for the
journey. Say 55t with some margin for error.

> so look at light oil,

If you're going to use oil, you might as well burn it in smaller cylinders
with internal combustion. The exercise was to see if it can be done with
coal, and I think it can.

>   I suspect that by now my 250 ton allowance for the locomotive

Why only 250t? The 8-8-8+8-8-8 came out to 520t.

Cheers
David