Off topic - starting tractor with Shotgun shell

I was watching a program on TV and they showed an old British made crawler that stated by building a fire with newspaper in a compartment in front of the radiator, then a 12 gauge shotgun shell was inserted and hit with a hammer. The machine fired up. I was left wondering about this design. Did the shotgun shell provide roational force? Did they use ordinary shotgun shells or blanks? It was impressive how well it apeared to work but as is always the case with television not much was explained. I assume the fire was to preheat the air intake. Anyone know how this system worked?

Here is a little note on how they started the old Field Marshall engines. I believe it is on about page 91.

http://books.google.com/books?id=-F84st7A1dAC&pg=PA91&lpg=PA91&dq=shotgun+shell+start+engine&source=web&ots=QuNRn9Cvm9&sig=sisx4x1caSYW7aG6DHwTRtWkzOg#PPA91,M1

Doug,

While I attended A+P School as a teen, one of my powerplant instructors told of a antique design radial type aircraft engine that used a shotgun sized cartridge to provide the umph to kick the crank and get the magneto sparking.

I think the film had the title "Flight Of The Phoenix" seen it recently on TV, there were quite a few cartridge start tractors about the UK in the early fifties, some were British built like the Marshall, it had a single cylinder engine and a very destinctive Pop------Pop sound, Lanz and Hatz made similar,they had a heavy flywheel that had to be turned to the right place,the cartridge was inserted,hit the firing pin a wallop and they would start right up, I cannot remember ever seen a fire been lit with the Marshall, there were hot bulb engines about in the early days that used a blowlamp to heat the combustion chamber,there was also a cartridge aided start,the piston was put to BDC,a plug was removed from the head,a sulphur cartridge about half the size of a cigarette filter tip was put in the plug and it was put back in place,one quick pull on the handle brought the piston up and it would strike the sulphur which would ignite,if you did not give the handle a good pull it would not but the crank over TDC and it would backfire and maybe start in reverse,many wrists and arms were broken,good old days eh.
AJ

Here ya go...
http://www.youtube.com/watch?v=rh1lxbelxVI&feature=related

Isn't it nice that all you have to do is ask and the answers come. Thanks for the information.