Improved Green Automatic Cut-Off Engine
This horizontal steam engine drawings set is based on the original automatic steam cut-off engine design by Nobel Green in 1838. The model has a 1 1/2 inch bore, 3 inch stroke and the flywheel is 11 ½ inches diameter.
This engine, built by the Providence Steam Engine Company in Providence, Rhode Island, incorporated variable steam cut-off several years before George Corliss patented his famous variable cut-off Corliss valve gear. Our model is based on a 150 HP, 17 inch bore and 36 inch stroke Improved Green Automatic cut-Off Engine that has been restored and preserved by the New England Wireless and Steam Museum in East Greenwhich, RI.
Green’s engine design used what has been known as a detachable valve-gear. The detachable valve-gear varies the steam cut-off point by using the engine governor to raise or lower trip points that operate levers to open the steam inlet valves. The higher the trip point, the longer the steam inlet valve stays open allowing more steam into the engine’s cylinder. The detachable valve gear was designed by Frederick Sickels and patented in 1841. Sickels was only interested in the marine applications of his valve gear and sold the rights to use his patent on land based engines to the Providence Steam Engine company. Then, when George Corliss introduced his variable cut-off valve gear in the late 1840’s, the Providence Steam Engine Company sued Corliss for patent infringement.
The court battle between George Corliss and the Providence Steam Engine Company raged on for over 10 years and became a landmark court case over what can and cannot be patented. In the course of the court battle, Corliss won an injunction preventing the Providence Steam Engine Company from building and selling the Green designed engine. The court case was finally settled in Corliss’ favor and Corliss’ original patent was extended by the US patent office on the basis that the law suits had prevented Corliss from benefiting from his patent.
In 1869, the Corliss valve gear patents finally expired and the Providence Steam Engine Company began producing the Green engine again. The Green Engine was given some minor upgrades and changes and then introduced as the “Improved” Green Automatic Cut-Off Engine even though it was basically the same engine Noble Green designed in 1838.
This detailed drawing package covers machining and assembling the model Improved Green Automatic Cut-Off steam engine.
- Scale: 1 inch = 1 foot (1:12)
- Cylinder: 1-1/2 inch bore x 3 inches stroke
- Flywheel: 11-1/2 inches diameter
- Overall size: 11 inches x 12 inches x 12 inches high
Castings & Drawings:
- The drawing package includes 106 sheets (11x17) of drawings and notes.
- Shipped via USPS in 1 package totaling 4 pounds.