1870's Farrar + Trefts / A.C.
Thomas Now Bessemer Half-Breed Oilfield
Engine Restoration
updated 12/08/01


Chilton M Farrar and Trefts (First name unknown) were steam engine builders in Buffalo, NY. They built steam engines which were used in the oil fields of PA, NY and WV. As the wells began to produce less oil at the close of the 19th century, the cost of maintaining and firing a steam boiler for a few hours a day to pump oil became prohibitive. Several machine shops in the Bradford, PA area began to offer kits to convert the steam engines to gas engines. Usually these were 2-cycle engines fired from natural gas available for "free" at the well. Ignition was usually via hot tube. This was a reliable ignition source in the days when batteries and magnetos were in their infancy. Below are pictured two types F+T steam engines which ware made around the1870's.

(Bob Campbell of Ontario, Canada added some information which I am including) "A(Allen)C.Thomas was a machinist who worked for Locke Machine Works for the period 1910-25. At this time Locke was a subsidiary of Bradford Supply. However Locke was in business prior to 1900, manufacturing amongs't ather things, steam engines. So it could be possible that there are breed combinations with a Locke steam frame. Nobody could tell me how it was that Thomas got to put his name on the cylinder or if other machinists got to do the same. I have not seen other names that would make one try to make a connection. Bradford-Thomas cylinders are a "borrowed" design from those manufactured by the Oil Well Supply Co., also a Bradford PA firm, and still known today internationally as a major supplier to the oil industry.

Bradford Supply (Bradford, PA) was organized in 1907 initially as a stores and pipe supplier to the burgeoning oil exploration & production
industry in Bradford Co. They quickly expanded by acquiring local foundry and manufacturing plants, including Locke Machine Works. I know they
existed until at least 1940. And at this point I am chagrined that I never established what happened after then. The founders of Bradford Supply (Robert Mackie & Thomas Hoskins) were born in the 1850's."

The following is a piece written by the founder and Board Chairman of the Bradford, PA Oil Well Museum, E.James Bryner on A.C. Thomas and is contributed by Susan Perry:
"If one proceeds north on Interstate Parkway, passing Bradford Area High School on the left and Bradford Regional Medical Center on the right and continuing on around the dog leg to left, headed, west, passing forst Stone Avenue on the right, you will then come to Parkway Lane. On the corner of Parkway Lane and Interstate Parkway is one of three Parkway Lane houses built by Chet Story, a local plumber."
"After passing the city limits on Interstate Parkway, the first residence to the right is the site of the old Thomas farm. This was the home of A.C. Thomas who ran a machine shop at 120 Chestnut Street. The upper end of the Thomas farm on the north side is Thomas Road, which marks the end of his property."
"Mr. Thomas used to work on old steam engines, boring out the cylinder so that they could be run on natural gas. Many of these early engines were manufactured by Struthers Wells, of Warren, PA."
"In the early days most wells were pumped with steam which necessitated having a boiler. Boilers were heavy and cumbersome, sometimes weighing as much as eight ton. Therefore, as natural gas was plentiful in the oil fields, the producers shifted from steam to natural gas to operate their pumping equipment."
"Mr. Thomas did a big business in his shop boring out the old steam engines to convert them to gas. These new pumping units were referred to as "half-breed" engines. A barker was placed on the exhaust to make it sound unique so that a pumper could tell when each individual pumping unit was operating properly, pumped off or shut down." (end of copy)

"I understand that Mr. Thomas got to put his name on the engines because it was his company that converted them into a different type of engine. We have a 15 HP Thomas half-breed, two-cycle gas engine in our museum with a barker attached which we run for the visitors. It is a sound dear to the hearts of oil country people. We also have a Farrar & Trefts steam engine complete with a Bovaird and Company pumping rig and an old Buffalo, four cylinder drilling engine."

My engine is a F+T early frame with an AC Thomas cylinder. The engine was in really rough shape when purchased. It was missing one of the gib keys on the con rod which I have since made. The piston was stuck tight in the bore about midway. The bore had a lot of water in it and a lot of rust damage in the bottom 90°. To free the piston, I heated the entire cylinder to about 750°F over 12 hours in an electric furnace to dehydrate the rust. Then I soaked the piston with a Canadian product called Releasall (available from MSC in the US). After a day or so I tried whacking the piston out with a slug of aluminum; it moved and with an hour, I had it out. I was going to have the cylinder sleeved, but the castings looked iffy to me. I have a background in materials engineering so I decided to try to come up with a patching compound to repair the cylinder walls without reboring and resleeving. As of 1/00 I have patched the cylinder to repair the deep pitting, and have tested the patch out on a model 5S Briggs and Stratton which I purposely bored off center (see the link on my home page).

A print of an 1870's early Farrar and Trefts(F+T) Steam Engine from the Buffalo City Directory 1880's.

A later version of the F+T engine circa 1872. I do not know the exact age of the two engines except that the earlier one from the 1870's appears as a "hog trough" engine and the later one appears as a box-bed engine. My crosshead bears a C.M Farrar patent date of 1876; it may be an improved crosshead installed at a later date as evidenced by the patent.


 A Farrar and Trefts steamer at Coolspring Power Museum. This is the early version like my half-breed.

 Bogart gas engine made by Farrar and Trefts at CPM. Flywheel size approx 36".

See US Patent 626,155 for details of the cylinder and Governor......go to my links to see it

All cleaned up and ready to run. I made the cart over the latter part of 12/99 from some 2x6" channel stock I purchased at the metal yard. The Wheels came from a junkyard and are 12"x5" with Hyatt roller bearings and urethane rims. I added a couple of drip oilers on the crosshead and a nice Detroit luber on the cylinder. The clutch now works just fine.

Alas, I tried to repair some really deep pitting in the cylinder with epoxy and I was just asking too much of it. Also, with no way to accurately hone it, it leaked through and lost compression after running ~20 seconds. During the summer of 2001 I found a Bessemer 7.5 " conversion cylinder which I fitted to this frame and the finished engine is shown above. I had to make an adapter plate to fit this smaller cylinder (for a 10-12 steam frame) to my larger 15 HP steam frame. Unless you know it is there it looks entirely original (?). I also had to make the eccentric which operates the governor. I made it split so I would not have to remove the flywheel. It started on the second tramp of the flywheel and barked along at 80-100 rpm!!! I like this cylinder more than the Thomas since it has the pendulum governor. With the smaller bore and the larger flywheel, this one runs real nice. Having the intake valve on the bottom really helps with preventing flooding and makes for easy starting. Hot tube length is 3". This seems to be a good length for slow running. Weight is about 2800 lbs.

If anybody has any info on this engine or wants to discuss halfbreeds, convertable engines or practically anything engine related, please write me an email c/o: pgray@dol.net. I am always also looking for "new" iron to add to the collection...so if you have any, or hear of any I might be interested in let me know. I like the rough challenges, but restored ones are nice too.

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