Stationary Engine Kits
Anthony Mount Models
Easton and Anderson Grasshopper Beam Engine
The grasshopper beam engine is so named because it is supposed to resemble a grasshopper when in motion. The Grasshopper engine was introduced in the 1820s and was built by many companies, but Easton and Anderson specialised in the genera. This model is based on an example supplied to Winchester gasworks in 1892. It was used to drive the gas exhausters that pulled the gas from the retorts and pumped it into the gas holders. The prototype was photographed in 1936 by George Watkins and was published in his book, “Stationary Steam Engines In Industry Vol 1, Fig 89”. 1892 is quite late in the thy for a grasshopper engine, but it does contain some “modern” features, such as double beam, single marine type big ends, disk crank, Meyer valves and Tangye governor. As a hole it has quite clean lines.
The model follows the prototype quite closely, but though it has an air pump, no condenser is fitted. The governor though it revolves is non operational. There are two eccentrics operating a concentric rocking shaft. But there is only one slide valve fitted, the other valve rod is a dummy. The two eccentrics are fitted as the concentric shaft is such an interesting feature.
The engine is quite small with a flywheel of 5” (125mm) diameter. Construction is quite straight forward, but some parts are quite small. Castings are available for the flywheel, base, cylinder, covers, rackets, rocking frame, and beams. There are 34 drawings and a parts list, all of A4 size. The dimensions are in both imperial and metric, you will find that some of the conversions are not exact as standard material sections are used where possible. The imperial dimension appears first with the metric dimension below. Drill sizes are given only in metric as these are now the preferred size.
The model can be built on a 3½” lathe, being quite small it might be possible to build it on some of the smaller lathes now available. All the work could be done on the lathe especially if a vertical slide is used. However a drill and mill will make things a bit easier. It is available as a set of castings, drawings and materials, or as castings and drawings only.
The engine does look very attractive in motion. The spinning governor is an added attraction. This was supplied by Tangye, a Birmingham company, and it is not known if this arrived with the engine or was added later. It was Tangye who supplied the Hydraulic rams that were used to assist the launch of Brunel’s Great Eastern steam ship. Grasshopper engines have also been used in marine work, some were installed in tugs.
The model was serialized in Engineering In Miniature from June 1992 to May 1993.