WW1 War Department 2 foot gauge Baldwin Narrow gauge
About this creation
In 1916 the British War Office ordered a variety of locomotives from various manufacturers for use on supply railways behind the trench lines. As the British manufacturers could not build enough locos quickly enough they also placed an order for 495 4-6-0 locos with the Baldwin Locomotive Works of Philadelphia, USA. Another order was placed with ALCo for 100 locos of a similar design, but with a 2-6-2 layout.
Nearly all the locos were delivered by the end of the war and they saw use by UK, Canadian and Australian troops. When the US entered the war they also placed an order with Baldwins, but again with a 2-6-2 layout.
After the war the locos were advertised for sale, but there weren’t many takers. In the UK the Ashover Light Railway in Derbyshire bought 6 while the Snailbeach Railway bought 2. A couple of other were bought by other lines. 50 went to India and some were still in use until the 1970s Another couple ended up in Australia and one is still in use, although with a major rebuild.
Planning for this MOC started with a CAD model over three years ago, long before BBB wheels were introduced. The basic construction and detailing of the body, cab and front footplate have remained from this time but the chassis and cylinder have been completely redesigned. The release of the BBB wheels was the catalyst for translation into the brick.
It was always intended to motorise the driving wheels, more for that sake of it than any thoughts of increased traction. The original plan was to use Jason Railton's 'centre wheels on sprung arms' design with an axle geared to the leading and trailing wheelsets running down the centre of the 1-wide backbone beam, however after reading that some of the real locos had blind drivers on the centre axle I decided to take this far simpler route.
The loco now has a 9v train motor at the front bogie, powered from this is a Technic gear motor (nearly) hidden in the firebox, a headlight and flashing lights in the firebox to represent the fire, the connection for all the wiring is hidden in one of the side tanks.
Making the front bogie and cylinders so that the the loco could go round curves and have the pistons still working was the hardest part of the design. The pistons were based on Teunis Davey's design, however despite seemingly having more room because of the larger scale, the presence of the large block of the train motor means that that cylinders have to be pretty thin.
The motor itself is not actually attached to the rest of the loco, it can slide sideway and rotate. The cylinder unit can only slide sideways, this keeps its alignment with the driving wheels well enough to work.
The final design for the front bogie was actually a halfway stage, I originally thought that the cylinder unit would need some sort of self-centring springing, however a test run showed that it worked so I left it well alone! The use of Technic Connector Toggle Joint Smooth on full length Technic pins seems to give enough play to allow for the sideways movement. The finished loco works on all standard Lego track including points, however it cannot be used with the track power connectors,  instead I have simply soldered a 9V wire with one end cut off to a curved section of track.
And the name? Well on the Ashover Light Railway the locomotives were named after the owner's children, Peggy, Guy, etc. Mine is named after my long suffering Lego-widow wife.
Here you can see the how the front of the loco rests on the front bogie and cylinder unit and allows the motor to pivot and slide and the cylinders to only slide. The Technic gear motor is visible, but I wasn't going to spend a fortune on a black one!
Wow, this is all very impressive. You don't see many trains in this scale, and I can imagine how difficult it would be. Also, it's great to see a WWI model. Maybe you could make some Miniland scale soldiers to accompany it? Man, I'd sure love to see it running with the working fire you have going inside. I have one question though. You said it doesn't work with the track connectors. What set-up did you use in their place? Again, wonderful train there.