Here is the thread clip from where it all started.
Jason - How about one of those old compressed air locos. Always thought that would be interesting to make one and have a air tank on it. Need to fill up at least 120psi do decent run time if a few mins id guess depending on the cylinders.
Henner - Jason,
we have thought about building such a compressed air loco. Unfortunately it seems almost impossible. 120PSi would give you probably just a couple of seconds of run time (120PSi expanded to say 12PSi = 10 times the volume of the boiler). Even 1200PSi would not cut it.
We also thought about dry ice (CO2), but here you run into two problems: Either the sublimation rate is too low or if the loco sits for a while, it creates dangerously high pressures. There have been attempts to sell dry ice powered locos, but they disappeared rapidly from the market...
Regards
Jason - Henner what about using the cans from a paintball gun? Of course refilling is the issue then.
Dan -
Real fireless engines were charged with steam. Unlike compressed air, as it was used it would still expand. The exhaust was reused, I don't know how. Most of them were small 0-4-0's and would run a full 8 hour shift and have enough pressure to make it back to their "charging" station. Many years ago there was one in Ft. Steel, BC that still ran, it's doesn't now.
Henner - We should not hijack Bill's thread. We could open a new one.
A fireless loco charged with steam would not work due to the rapid heat loss in a model. A paint ball tank might work. I just made a quick calculation and the range would be close to a mile (67cubic inches at about 3000PSi -> 6700 cubic inches at 30PSi). But you need to integrate the tank into a loco and also find space for the pressure regulators (probably two step). And then of course refilling the tanks.
Regards
Jason - How about one of those old compressed air locos. Always thought that would be interesting to make one and have a air tank on it. Need to fill up at least 120psi do decent run time if a few mins id guess depending on the cylinders.
Henner - Jason,
we have thought about building such a compressed air loco. Unfortunately it seems almost impossible. 120PSi would give you probably just a couple of seconds of run time (120PSi expanded to say 12PSi = 10 times the volume of the boiler). Even 1200PSi would not cut it.
We also thought about dry ice (CO2), but here you run into two problems: Either the sublimation rate is too low or if the loco sits for a while, it creates dangerously high pressures. There have been attempts to sell dry ice powered locos, but they disappeared rapidly from the market...
Regards
Jason - Henner what about using the cans from a paintball gun? Of course refilling is the issue then.
Dan -
Real fireless engines were charged with steam. Unlike compressed air, as it was used it would still expand. The exhaust was reused, I don't know how. Most of them were small 0-4-0's and would run a full 8 hour shift and have enough pressure to make it back to their "charging" station. Many years ago there was one in Ft. Steel, BC that still ran, it's doesn't now.
Henner - We should not hijack Bill's thread. We could open a new one.
A fireless loco charged with steam would not work due to the rapid heat loss in a model. A paint ball tank might work. I just made a quick calculation and the range would be close to a mile (67cubic inches at about 3000PSi -> 6700 cubic inches at 30PSi). But you need to integrate the tank into a loco and also find space for the pressure regulators (probably two step). And then of course refilling the tanks.
Regards