Return of the ‘Royal Highland Fusilier’

This is a very special Mardyke Deltic miniature locomotive, being the only one out there running on twin engines.
Why? Because its owner wanted it to, and Chris could complete the challenge.

The process began by stripping it down to its bare frame and body. The first task was to construct a new subframe capable of mounting two engines and two hydrostatic transmissions. The key requirement was that the engines should operate in tandem, with the ability to run only one at a time.
The driver’s throttle and transmission control needed to operate both systems simultaneously. Everything, including the transmission dump valves, had to be controllable from the cab.
With the engines and Hydrostats successfully trial fitted the next job was to connect it all up. Two ignition circuits were required so that the engines could be started and shut down independently. With the wiring complete and two custom exhausts fabricated it was time to fire it up!
Both new engines started almost immediately, and the combined throttle worked perfectly. Next up was connecting both hydrostats to the common propshaft using 1/2” pitch simplex chain. The loco was then run up again on blocks to check the drive system and the combined transmission control lever. With everything working as intended it was on to track testing at Barnards Miniature Railway in Essex. Initial runs were successful; however, the loco was just too fast, easily capable of reaching 12+ MPH. So it was back to the workshop for a change to the final drive gearing. This would give us more power and a speed closer to 10 MPH at full power.

The loco returned to the workshop for mechanical completion, also fitted with new wheelsets and axles. It returned to its owner on Friday 20^th March, where they enjoyed a days running round the railway in the spring sunshine.