Duane Johnsen is the Chief Engineer of this magnificent 130 ton Cooper stationary steam engine. The engine is owned by the Stephenson County Antique Engine Club, Freeport, IL, USA.

 COOPER1

As you can see by the photo, the engine is a Corliss valve arrangement utilizing two eccentric rods. The engine was originally equipped with a 12 inch steam line but we have equipped it with a 3 inch line to enable us to run it for demonstration purposes. It does run and we have it operating on several weekends during the summer.

The cast iron totals just over 130 tons US. The rolling portion alone (minus connecting rod, etc., etc.) weighs in just over 88 tons US. The flywheel is composed of 12 sections of cast iron each weighing about 5 tons US. When we recovered the engine from the Zinc rolling mill (in LaSalle, IL, USA), the governor was set to operate the engine at 45 r.p.m. I figure the maximum speed of the engine was about 60 r.p.m. We operate the engine somewhere between 3 and 18 r.p.m. for demonstration purposes. We have no load on the engine due to the small boiler to which we have connected the engine (it is just adequate enough to run the engine).

COOPER2

The clubs goal is to preserve history and this engine formed a major part of the industrial history of this area. Besides that it is extremely fun!

The Stephenson County Antique Engine Club can be found in the Club Listing on this site. If you have any questions send them to me at This email address is being protected from spambots. You need JavaScript enabled to view it..

Thanks to Duane for contributing this article.