I am an engineer connected with the engine
industry, and am interested in internal combustion engine history and development.
Here in England many societies, clubs, and individuals are
actively engaged in the acquisition, restoration, and preservation
of steam traction engines, road rollers, etc., but by comparison
with the activities of gas engine enthusiasts in the United States,
little has been seen of such activities in England. There are a few
people here with good collections of old farm tractors, but it
would appear that war time scrap drives eliminated vast numbers.
In 1964, I purchased a 1933 10 ton oil engined road roller.
Although this machine is relatively modern, it is almost unique, as
its power unit is a single cylinder Blackstone oil engine. This
roller was probably one of the last to be produced by Aveling and
Porter of Rochester, before amalgamation with Barford Perkins of
Peterborough, to form Aveling Barford Ltd of Grantham.
The engine of the roller is quite large, of 7-inch bore and 14-inch stroke, built on gas engine principles. The connecting rod and
crank are enclosed by a sheet metal cover.
The engine is in fact a low compression diesel, starting from
cold being assisted by an igniter. Rotation of the engine for
starting is produced by compressed air stored at 400 PSI in
seamless bottles which are refilled by back charging from the
engine.
Fuel is injected by Carters patent spring injection system,
consisting of the injector block mounted on the cylinder head, and
a low pressure metering pump operated by an eccentric on the camshaft.
The centrifugal governor is driven by skew gears from the
camshaft, and it controls the effective stroke of the metering pump
plunger. Gas oil from the metering pump is discharged into a spring-loaded accumulator cylinder in the injector block, then the operator uses a crank on the end of the camshaft to wind the accumulator spring, creating injection pressure of about 1,000 PSI. At 15 degrees from T.D.C. a toppet relieves part
of the load on the injector needle valve, permitting fuel to be
injected.
The engine is lubricated on the total loss system by a 4 point
lubricator with sight glasses: 2 points feed the liner, 1 point feed
each main bearing, and excess oil is collected by banjo rings and fed
to the big end. I use an H.D. 30 oil.
The engine is cooled from a 120 gallon water tank under the
footplate. A plunger pump operated by an eccentric on the camshaft
circulates the water.
The exhaust is conducted up a steam engine-type chimney; when I take this machine to steam rallies, many people wonder where the fire-box is!
The engine speed can be varied between 130 R.P.M. idle to 350
R.P.M. maximum by a hand wheel operated from the footplate, which
controls the load on the governor spring. The engine develops
approximately 20 BHP at 350 R.P.M.
The drive is taken from the engine by a duplex
chain to the gear box input shaft, through either the forward or
reverse cone clutch. The gear box has three speeds, giving 4 mph
in high, 2 mph in second, and 1 mph in low.
I purchased the roller in rough although running order, and was
helped in its restoration by members of the Colchester Society of
Model and Experimental Engineers. The cylinder liner is badly worn,
but I have considerably improved the power by detailed attention to
the fuel injection equipment and fitting new piston rings.
During the last two years, I have attended several steam engine
rallies with the roller. It has attracted a great deal of interest,
and gives rise to most interesting comment.
I have traveled about 100 miles on the road with it to these
rallies. Gas oil consumption is about 7 mpg. Running light, the
engine burns one gallon in four hours.
There are not many stationary gas engines in preservation here. The only engines I have seen have been a Fairbanks Morse and an
Amanco.
I was most interested to see that Gas Engine Magazine is preparing an article on the Hornsby
Akroyd engine, as I have recently
found a 1907 6 HP Hornsby engine, No. 29270, belonging to Mr. S.
Hills, of West Mersea, Essex, and am endeavoring to mount it on a
trailer so it can be taken to traction engine rallies. I have
obtained information from Ruston & Hornsby Ltd., and am
enclosing with this article photostat copies of the instruction
book and parts list.
These engines were manufactured under license by the De la
Vergne Co., of New York; Manufacture of these engines in England
continued until 1920.
The photograph of the roller on the front of the April-May
1967 G.E.M. was most interesting, as many features on this machine are
similar to Blackstone engined rollers manufactured by Aveling and
Porter, between 1926 and 1932.
