From Péchot-Bourdon to Baldwin Gas Mechanical

In 1887, Prosper Péchot and Charles Bourdon designed the first of the remarkable Péchot Bourdon locomotives. The design had some interesting features, distinguishing it from the Fairlie which provided the inspiration. The boiler, powering two separate steam bogies, ran right through the locomotive. Locomotive frames supported the boiler, tanks and cab and kept the power bogies in place.
The first Péchot-Bourdon was delivered early in 1888, and, following official approval in June of that year, a total of roughly 60 were delivered to the frontier fortresses of late 19th century France. I say 'roughly 60' We can be certain that an inventory of 1913 lists 54 in France, and 3 in Morocco. This suggests 57. At the beginning of the First World War, the French were woefully short of transport between standard gauge railheads and the trenches. 60cm railways were best suited to the job. Within months, the Army had placed orders for Péchot Bourdon-locomotives with the North British Locomotive Works, Scotland and the Baldwin Works, Philadelphia USA. These engines was numbered off from 62 which suggests that the Army already had 61.

This fine 16mm model of a Péchot-Bourdon paying a visit to the British Front shows the sinuous shallow curves typical of late nineteenth century French design. Layout by the late Henry Holdsworth.

 The Baldwin Works delivered 100 Péchot-Bourdons in three months, keeping two for trials in Canada. They made 280 altogether. The design, economical yet complex, struck a chord with the factory and they tendered for further business from the French Army. Meanwhile, the factory made a few steam locomotives for the British.

The Baldwin WD 4-6-0 side tank. 495 were produced between October 1916 and April 1917 to supply the British Army. 16mm model built by Wrightscale

By 1915, the French Army realised that steam locomotives were highly visible near the Front. By day, their column of steam made a good target, by night so did the sparks from the fire-boxes. On October 14th 1915, they had put in their first order for 40 petrol-engined locomotives with the Schneider company of France. Trials began in 1916. Wastage, when the petrol engines were in use on the Western Front, was horrific. By May 1st 1917, 15 locotractors were left, by 31st August only 7. For internal combustion locomotives, the Army turned to Baldwin once more, just as their new ally, the AEF did.
In 1910, Baldwin had patented a gearbox suitable for an internal combustion engine and they now offered two designs based on this - two-speed locomotives both offering 4/8mph ie 6.4/12.8 km/h. One Baldwin Gas Mechanical (BGM) model was 35 horsepower, the other 50 horsepower. Petrol consumption per hour ie 4 miles was 3.5 US gallons for the smaller locomotive, 5 gallons for the larger one (taken from manufacturer's catalogue no 95). This gives an environmental-busting fuel consumption of 2 or less miles per (American) gallon. At the time, this was fairly standard. The French alone ordered 600, all 50h.p.

Jim Hawkesworth photographed this fine preserved example of a BGM in the museum at Froissy. The beautiful lamp which should be on the bonnet front has been lost. What is the horse-power? Hint: the panes of the windscreen are square and the petrol tank on its bonnet  is quite long. Yes. It's the 50 h.p.

 A familiar sight on the Western Front duning the last stages of the war, Baldwin locotractors have certain charms in addition to their historic value. The petrol tank is mounted on top of the bonnet along with with the exhaust chimney and the handy electric light (powered by a dynamo with back-up battery). All these protruberances along its 'nose' give it the characterful look of a rhinoceros. The overall design looks both to the past and the future. If the exhaust chimney harks back to steam, the split windscreen looks forward to the age of the automobile.
Most charming of all are the side-frames. As a certain television presenter might say, being clearly visible, these frames give the structure an honesty and raw integrity that is better than sophistication. In layman's terms, we can see what is holding the machine together, and that is reassuring! Furthermore, in their angular way, the design of the locotractor frames looks forward to Art Deco, whereas the spare shallow curves of the Péchot-Bourdon frames look to the emerging Art Nouveau of their period. If you have the good fortune to have a copy of Christian Cénac's La voie de soixante sur les fronts français de la guerre de 14-18, look at plates 10 and 35. The rest of us can only beg Dr Cénac to reissue the book.

This BGM model under construction shows the frames and motion more clearly. Malcolm Wright

As noted before, the wastage on the Western Front was horrible - for humans, animals and machines. Few BGMs survived until the Armistice. Some were kept by the Army. There is a photo of no 46,619 (manufacturer's number) at Toul in the late 1930s.  Where power rather than speed was needed, eg in quarries, others were purchased by civilian users. On a number of occasions, the new owners fitted the machines with more modern and frugal engines. This is reminiscent of the crusty old joke: 'My husband and I decided to save power, so I switched off his life support machine.' Moelwyn, which can be seen up in Wales, suffered this and other indignities.
If you stumble across a forgotten Baldwin locotractor in a French barn, you will want to know whether it is a 50 h.p. or 35 h.p. model. Dr Cénac lists the signs (op. cit. p 81). Here are a couple. The 50 h.p. model has a larger bonnet and so the divided windscreen is less deep than that of the 35 h.p. It is composed of two square panes whereas the windscreen of the less powerful model is made up of two upright rectangles. The petrol tank on the smaller model is shorter and there is little space between it and the exhaust.
Possibly, if we had asked an operator of the time, he (usually he) would have said of the BGM 'Bit top heavy and hard to reverse, but I like the lights'. As with any rhinoceros, Art Deco or otherwise, they moved away pretty quickly when it charged.

Hunslets - On the home run - early March

Hi, I have been very busy in the workshop since I last put up a post.  The boilers have been made and tested, all the gas system, gas tanks, valves, burner and pipework has been made and tested.  Over the last week the boilers and gas systems have been erected onto the running chassis.

It all fits together  but the smokebox still has to be bolted to the footplate.

Most importantly the burners have all been installed into the flues and they all work very nicely, lighting first time and burning well.  What remains now  is to make all the banjo unions and bolts, complete the water filling system, safety valves and purchase the pressure gauges and fit them.  That is quite a lot of work, but once done all that remains is plate work. There is nothing left to do that will be critical to the performance of the locos.

Here is the batch, 11 locos, space is getting short!

You can see from the photos how once there is a smokebox and chimney the Alice Class Hunslet starts to appear.  It is clear why I cannot make more than 10 or so locomotives at a time, there is no space , I just run out of surfaces to keep all the bits on! When will they be finished? I was hoping for the AGM and that is still my goal but failing that they will all be gone by the end of May making space for the next batch.