Sheffield Tool and Supply Co.

By Staff
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Another view of the engine.
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12 HP Sheffield, last one in U.S.A., photo taken July 1990.
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An ad for an O'Connor rigged tractor from a 1937 issue of Producers Monthly.

3286 Cramlington Drive, Gibsonia, Pennsylvania 15044.

As with most engine collectors, there seems to come a time when
the collector needs to move into a larger engine, something in the
10 to 15 HP range. The club that I am a member of, the Northwest
Pennsylvania Steam Engine and Old Equipment Association, located in
Harmony, PA has a display of Pennsylvania made oil field engines
that were unique to our state. I have had a longing to find one of
these engines that was unique to the oil boom here in Pennsylvania
at the turn of the century; this article is about such a find.

At our club, we have on permanent display a 15 HP Berry from
Petrolia, a 15 HP Evans from Butler, a 15 HP Ball from Butler, a 20
HP Bessemer from Grove City, a 12 HP Price Brothers from Renfrew, a
15 HP Reid from Titusville, and my engine, a 12 HP Sheffield from

In the fall of 1987, while traveling over one of my favorite
roads to go hunting north of Butler, I saw the find of a lifetime!
From Route 38 near the small village of Hooker a large pair of
flywheels could be seen coupled with an engine base. Over top of
the engine was a leaning walking beam and ban wheel surrounded by
small red maples and brush. I had passed by this engine for several
years just chalking it up as another dead engine from a once great
oil boom era. One day I decided to drive up the farmer’s lane
and meet the owner, Mr. Robert Saper, who gave me permission to
look the engine over after I told him about our club and its
functions. Well, I ran over to the engine, but found myself side
stepping several electric cow fences and bramble thickets before
getting to the engine site. The engine name, cast into the side of
the bed plate, read SHEFFIELD, nothing else, just Sheffield.

The engine is a two cycle design with a cross head and hot tube
ignition. The engine had a pair of mismatched flywheels, one with a
counter weight about 40 degrees from the throw of the crank; the
second wheel had the counter weight with the throw. The original
builders plate was missing so, at this time, the actual horsepower
could only be a guess, and yes, it was frozen. The cross head wrist
pin brasses were intact with a partial brass half still connected
to the connecting rod. The other half would be discovered during
the removal of the engine. Some of the original paint was found
under the grease that had leaked from the main bearings. It was a
faded red, so I have painted it Regal Red with glossy black

The only Sheffield that I knew about at this time was the
village in England or a small village to the north of Butler, PA,
approximately 100 miles. Sheffield, PA was made famous during the
early white pine timber harvests followed by the early oil boom
around 1890 to 1900.

After coming to a purchase price and getting the engine home,
with all of those nightmares which accompany removing large
engines, did the real fun begin: finding out about my new

The engine was made in Sheffield, PA at the Sheffield Tool and
Supply Company. This company was founded by Morgan Mainwaring in
Barnes, PA circa 1880. Mainwaring moved his machine shop to West
Main Street in Sheffield during 1882. Twenty years later David
Mainwaring and Frank Havens bought the plant and moved it to the
corner of Center Street and Horton Avenue. Mainwaring and Havens
began to manufacture tractor hoisting devices such as winches and
small rod pulling towers that could be attached to crawlers or
steel wheeled tractors such as the Fordson. The company with its
seven milling machines also outfitted steam engine bed plates with
gas cylinders turning the engines of this time into ‘half
breeds.’ Cast into the cylinders were the names of Barnes and
Mainwaring. Later on this logo was to be changed to Sheffield. For
some time visitors to our club would look at the Sheffield and try
to decide if my engine was a half breed or a true natural gas
engine. It has been determined that my engine is a true gas engine
and not a half breed. In the company’s last few years the
larger engine companies, mentioned earlier, were putting half breed
builders out of business. In a final attempt to stay with the
competition, the Sheffield Tool and Supply Company did begin to
build a few prototype natural gas engines with the heavier bed
plates. My engine seems to be one of these.

In my many miles of traveling up and around the towns of
Sheffield and Barnes, I have only been able to locate one other
Sheffield engine. It is stripped down to only having the bed and
cylinder left. It had a 12 inch bore and a 4 inch crank journal. It
now sits along the lower side of Sheffield near the Tionesta

My engine appears to be approximately 12 HP with a 7.75 inch
bore. This horsepower size is comparable to data found on the Ball
Gas Engine Company of Butler, who lists a two cycle engine with a
7.50 inch bore as a 12 HP. The cross head babbitt on the bottom of
the cross head had worn away many years ago, causing the piston to
rub on the upper cylinder wall causing the cylinder to become egg
shaped. Thanks to the efforts of Joe Sykes who was able to bore the
cylinder true again and spray weld the piston to fit, the Sheffield
was able to run once again.

Special thanks go out to Mr Tom Molnar of Saxonburg, PA for
tackling all the other problems encountered in trying to get her
going. Some of these were re-fitting the cross head with brass
glide bars vs. babbitt. The top half of the babbitt was in mint
condition so he fabricated brass slide bars and machine screwed
them into the bottom of the head. Another problem was that on the
bottom of the cylinder there was a missing air mixer plate. He
fabricated one from aluminum and fitted it with a one inch pipe
nipple and gas cock to regulate the air flow.

Another problem was the connecting rod bearing which had been
babbitted once before in an attempt to make it fit the crank. This
bearing was in very sad shape and knocked when the engine would
run. Tom was able to use my bearing as a pattern and have a new one
cast up, machined down and fit to the crank. The atmosphere valve
had to be reseated to the valve seat and the packing gland that the
piston rod slides through had to be bushed. We also had to remove
both flywheels. By turning one around, we were able to position the
counter weight in the correct position opposite the crank throw. On
the site we found a third flywheel which had no counter weight in
the casting so it was put on rather than having the expense of
trying to re-broch a new key way in the oddball flywheel; that was
one foot smaller in diameter anyway.

All in all you might think that the engine is turning out to be
one of two ever known to exist. Perhaps someday the right flywheels
will show up. If you are in western Pennsylvania the Sheffield
along with all the other engines mentioned and some I might have
missed are on display at our showgrounds in Harmony, Pennsylvania.
Stop in and visit, we would all like to visit with you!

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