A1 Steam Locomotive Trust tests new alternator

Builders of new steam locomotive No. 2007 Prince of Wales, the A1 Steam Locomotive Trust has tested a newly-designed and built axle-driven alternator.

The new design will be used by the Trust to replace the Stones Altonum alternators presently used from early British Railways Mk. 2 coaches of the early 1960s, parts for which are becoming scarce, with costly overhauls.

This further step to the completion of No. 2007 Prince of Wales demonstrates new solutions which the Trust is finding to ensure it can continue to operate steam on the modern main line railway. Fitting the necessary electronic systems to its locomotives will provide the increasing amount of electrical power for trains.

Electro Magnetic Compatibility testing was conducted by contractor Eurofins of York on the morning of Thursday, October 21 using 1920 Leeds-built 7NHP Fowler steam road engine Providence. Owned by Howard & Barry Stafford of Houghton-le-Spring, the engine comes complete with belt and is a two-cylinder compound with a governor which makes it ideal for the task, it not producing electrical interference. Testing was performed from the lowest to the highest speeds using a large flat belt as used for operating saw tables and other accessories.

Commenting on the testing, Head of PR and Marketing, Mark Allatt said, "The new alternator uses a 180A 28V truck/bus alternator fitted into a solid steel casing. We have fitted a 2.5:1 toothed belt drive system within the casing to get the alternator running at the required speeds from the axle pulleys on coaches or in our case the tenders on Peppercorn A1 No. 60163 Tornado and Gresley P2 No. 2007 Prince of Wales. We have built a test ring to check output, temperatures and endurance running. As the test ring comprises a squirrel cage induction motor with an electronic speed controller, it is likely to produce a significant amount of electrical noise in its own right. With this in mind it occurred to us that a suitable drive system for when EMC testing would be a medium sized traction engine."

The new alternator design will be fitted to No. 60163 Tornado, No. 2007 Prince of Wales, its proposed Gresley class V4 and support coaches. For further updates on the project and more information on its current engineering challenges, visit the A1 Steam Locomotive Trust.