The Steam roller and traction engine - a brief history
The Mamod SR1 roller was Mamod's first mobile steam engine.
Designed by Eric Malins and inspired by the 'Mastrand' roller of the 1950s. Early rollers are easy to spot - all have the
one-piece burner and scuttle (rivetted together) and no tow hook. Also these early engines were mostly put togther using screw
fixings. At the time of the introduction of the TE1 traction engine (or steam tractor), the brass one piece burner and scuttle
was dropped and the standard Mamod black vapourising lamp introduced. The roller now had a tow hook, although curiously enough
Mamod themselves never added to the range any sort of trailer or wagon for it to pull until 1969.
In 1965 all the screw fixing were eliminated and 'pop' rivets
employed. The earliest forms of SR and TE are what enthusiasts refer to as 'Nut and bolt' versions. From 1967 both the SR1
and the TE1 became the SR1a and TE1a respectively as the engine unit became bi-directional. The Tractor lost its exhaust throttle
with this modification. Early versions of these had straight control levers and are hard to find (see 1967 TE below). The
roller gained mazak rolls in about 1968, making a straight levered, aluminium wheeled SR1a a very hard to find variation of
this long lived design.
In 1972 the turned brass whistle was replaced by the spring
reset whistle - the brass version looked nice, but positioned on the top of the firebox (in the case of the roller and tractor)
made it near impossible to operate without a cloth or gloves!!
Another major change came in 1976 when solid fuel replaced
the meths burners on all Mamod engines. In 1977/8 sight glasses replaced the overflow plugs.
There have been many other
minor iterations of the roller and tractor, as well as special one off variations and I may go into these at a later date.
Suffice to say these two staples of the Mamod steam stable are still going strong today, and although they have now been joined
by a much broader range of mobiles its the SR and the TE which will always capture my imagination.