Re: Thought exercise - steam VFT

["William Pearce" <ben_issacs@optusnet.com.au>]

        In re Dave's comments , he suggests using 5 x50 ton double-deck
coaches, would 50 tons with a double-decker  be possible with 1930's
technology, then he adds a 520 ton loco, so his train weight came out not
much different from mine. One has to move the loco as well as its trailing
load.
  He still has not dealt with the problem of ash build-up in the ashpan and
consequent choking of the grate, also the actual distribution of coal over
such a large grate would be difficult with the normal steam jet discharge
arrangements, and I still feel that the weakest part of his design is the
water pickup requirements .
                                              Regards,             Bill
Pearce.
"David Bromage" <dbromage@fang.omni.com.au> wrote in message
qkbA5.16$WT1.3853@news0.optus.net.au">news:qkbA5.16$WT1.3853@news0.optus.net.au...
> 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