RA> Why? A Beyer-Garatt (sp?) type engine, perhaps burning
RA> pulverized coal or a coal/water slurry, would work quite nicely.
AC>Coal water slurry is a proven power station option [stationary
AC>power stations!] but has this fuel ever been used in a loco?
AC>The considerable weight of all that water would reduce the possi-
AC>ble revenue ie the tonnage *behind* the tender. Then there is the
AC>energy loss involved in vapourising the residual water. In a power
AC>station, the slurry is not burned until well drained and aerated,
AC>a process that might take days between coal receipt and use.
No. (I did a senior project with the stuff in University.)
CWS is like ink, or very black paint. (It tends to spread...)
It's typically no more than 30% by wt. water; and the water
actually helps the combustion process. (It dissociates into OH
radicals, which attack the soot, for more efficient combustion.)
The coal is very finely ground; as I say, like paint. The heat
used to vaporise the water is a small fraction of the heat of
combustion, so that's really not a big concern, esp. considering
that handling the slurry has less parasitic power requirements
than lump coal does.
AC>You have proposed that a rigid set of drivers as in conventional
steam locos, is sprung and equalised sufficiently for you to compare
with elec motor bogies.
"Rigid" set of drivers? Not hardly! Look closely...
The side rods have joints near each crank pin, except at the ends.
The drive axle journal bearings are in blocks, which float up and
down in slots designed into the loco frame. Note that this vertical
motion is at right angles to the drive forces applied by the rods,
so the two are independant. The leaf springs above each journal are
linked at the ends to the next one over, so that all work together
equalizing the weight from one axle to the next, and the next after
that... The suspension on a steamer is much more complicated than
the drive rod system! Note also that the rotating mass of all the
drive rods, and half (exactly) of the main rods, can be counter-
ballanced in the wheels.
RA> [fully] sprung and equalized. The equalizing system adjusts
RA> the spring tensions so that all axles receive their share of
RA> the burden. Note that lead and trailing truck axles are
RA> typicaly included, but at a lesser rated burden.
I have no problem with the dynamics of the lead and trail bogies. The
springing of these could be as good as on a Bo Bo elec or de body. But
I won't buy the principle that the main drive wheels of a conventional
steamer, are uniformly sharing the burden of the train on- the- move.
Because-
> The drive wheels and axles have very high mass hence inertia, and
will more slowly respond to the ups and downs of the rail head.
* Not relative to the vertical forces involved; plus the track
doesn't go up & down that sharply. Rail doesn't bend that way.
> The heavy side rods, pinned to each drive wheel, also restrain any
independence of vertical movement of any single axle as IT passes over
a valley or hill in the rail head.
* No; as I said, they're jointed near the middle crank(s).
> The springs that serve each axle are much "harder" than those
of a conventional motor bogie. The bogie of today has multiple
springs and links. Not just one spring per axle box!
* No; if you consider the (change in force) per (unit traveled),
the steam loco's spring /system/ is MUCH softer than "bogies".
>And, I don't think there is much scope for designing springing
>improvements into a set of 6, 8 or 10 couple drive wheelsets.
Not necessary. It's already quite soft & flexable.
>The solution is easy. Frugal living, village life, windmills and
>solar panels, demolish the shopping malls and restore the cornfields.
>Plus negative population growth.  Cheers......ALEC
Three quarters of the world's population has to die, so that the
remainder will have...  a poorer life? Not likely. :)
Reggie Arford
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 X SLMR 2.1a X My reality check just cleared.
--- Maximus 3.01
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