Thank you to Alex Dow, Fife,
Liquid to Gas
"Gases typically are around 800 times the
volume of their liquid version, ie one cu foot of most liquid forms of a
gas will occupy about 800 cubic feet. For example, the steam from a
litre of boiling water occupies about 800 litres.
LPG or Liquified Petroleum Gas as mooted for
motor vehicles today, for any given liquid volume has only about 55% of
the energy content of the same volume of conventional petrol."
"That is for every litre or gallon of petrol
used in a car, it would need almost 2 litres or 2 gallons of LPG in liquid
form to cover the same distance. Hence one litre of LPG costing
roughly 50% of one litre of petrol. So the gases produced in those
Producer Gas Trailers during WW2, provided relatively little energy
compared to petrol or diesel.
Gas also does not have the natural lubricating
properties of petrol and more-so diesel, so with the need to keep the
buses in low gear even more than usual, there would be a lot of friction
and wear - not what you want during a war particularly."
"This resulted in the buses being grossly
underpowered; and therefore not successful in a hilly town such as
Edinburgh, especially as there is the additional weight and friction of
the trailer and solid fuel to trail around. It is also why very few
commercial vehicles run on LPG today.
They were of more use on flat routes; and some
of the SMT country runs may have been suitable, such as along the coast to
Port Seton, although I don't recollect actually seeing any SMT buses with
Alex Dow, Fife, Scotland, December 5+6, 2006
More comments from Alex Dow
Thank you to Alex Dow for also
sending me his comments on:
gas-powered buses in WW1 and WW2, and
- gas trailers at
Central Garage, Annandale Street in WW2