Historical information

The Davey Paxman Experimental Steam Engine was purchased by the Ballarat School of Mines as the result of a bequest from Thomas Bath.

Physical description

The Davey Paxman Experimental Steam Engine was purchased as the result of a bequest from Thomas Bath. The 'substantial sum' was used to build an Engineering Laboratory. The Ballarat School of Mines Council minutes of 08 November 1901 record: - Plans for [the] proposed building were submitted ... and ... it was resolved that a temporary building for an Engineering Laboratory be put up.' This laboratory, as an existing building, is first mentioned in the Ballarat School of Mines President's Annual Report of 1901, presented on 28 February 1902, reporting 'the erection of a building 67ft long by 33 ft wide' This report also lists all the equipment that would be accommodated in the Engineering Laboratory, including the experimental steam engine and boiler. The experimental Davey-Paxman steam engine arrived in Ballarat towards the end of 1902. The Engineering Laboratory was opened on 14 August 1903 by His Excellency Sir Sydenham Clarke. This engineering laboratory remained in use till about 1945. By 1944 preparations were under way at the Ballarat School of Mines to expand existing facilities, to be ready for the influx of returned soldiers. A new Heat Engines laboratory was built, this time of brick construction, replacing the previous corrugated-iron shed.

In the early stages the steam engine was used to drive an overhead transmission shaft for machinery in the adjacent workshop. Later the steam engine was moved to a space that became the Heat Thermodynamics Laboratory. At the end of 1969 the engine was relocated to the Thermodynamics Laboratory at the then Ballarat Institute of Advanced Education (BIAE) Mt Helen Campus. It was donated to Sovereign Hill in 2006.

According to the research of Rohan Lamb in 2001 around five experimental steam engines were made by Davey Paxman, and three of these had similar configuration to the Ballarat School of Mines Steam Engine, however, each of these was also unique with different valve arrangements. The list, which was on a scrap of paper in a folio held in the Essex Archives, confirmed that one was sent to India. The Ballarat steam engine can be dated to late 1901 to early 1902.

Zig Plavina was responsible for moving the steam engine to Mount Helen, and worked on it as a technician for many years. He observed the following:
* The condenser is driven by the low pressure engine.
* The following arrangements are possible:
i) the high pressure engine alone, exhausting to atmosphere. Condenser not used, crankshaft flanges not coupled.
ii) crankshafts coupled, mains pressure (120 psi) steam supplied to high pressure engine, partially expanded steam delivered to low pressure engine (Tandem operation). Choice available re exhaust steam: either to the condenser or to atmosphere.
iii) crankshafts not coupled, reduced pressure steam supplied to low pressure engine. Exhaust steam - either to the condenser or to atmosphere.
* Valve arrangement - a choice of Pickering cut-off or throttle governor. On low pressure engine - throttle governor only.