8 INCH ERICSSON WOOD FIRED STIRLING CYCLE PUMPING ENGINE

8 INCH ERICSSON WOOD FIRED STIRLING CYCLE PUMPING ENGINE

8” Bore, 4 “ Stroke, beta type hot air engine.

Engine number 22,835 (not yet dated) but probably 1920’s

Swedish born American engineer John Ericsson (1803 -1889) entered a well-designed locomotive (“The Novelty”) in the famous Rainhill trials (England) in 1829, losing to Stevenson’s Rocket (Ericsson had not given himself sufficient time for testing before the competition, had a boiler malfunction on start-up).  He then developed hot air engines and between 1852 and 1858 built “The Ericsson”, a 2,200 ton ship powered by a 4 cylinder (4.3m bore, 1.8m stroke) “Caloric” open cycle air engine- which was a commercial failure. Smaller single cylinder versions were successful with more than 1000 sold by 1861.  Ericsson then designed and developed the USS Monitor iron clad for the Union forces in the American Civil war (which used a conventional steam engine).  From the 1850’s he switched to developing closed cycle (Stirling) air engines, eventually settling on the beta type (piston and displacer  in a single cylinder), of which this is an example.

The “Pumping Engine”, developed in the 1870’s, was Ericsson’s most successful design. It was originally called the “Sun Motor” and used a solar reflector for heating.  With firebox heating, they were available in 5, 6, 8 and 10 inch sizes. These and Rider 2 cylinder alpha type Stirling engines are the most successful hot air engines ever.  More than 30,000 Ericsson Pumping Engines were probably sold by various licensees up to when production ceased in 1933.

They were used to pump water for stock and domestic uses- and were said to be so simple that even a servant could operate them.  Burning wood or coal (there was also a gas version), they’ll start within 20 minutes of lighting the fire and will then run continuously if stoked every hour or so.  The piston seal is leather and lasts for years providing it is supplied with liberal dosing’s of neatsfoot oil. 

This one, made by the Rider-Ericsson engine company in New York (where Riders were also made), was found at Tarras in Central Otago.  It was collected by Ray Gillespie and restored by Roger Mahan.

PETER LYNN for the Mahan Heritage Centre, 2025