A 16mm Péchot bogie wagon kit

Firstly, we apologise to our loyal customers. The 16mm Baldwin Gas Mechanical model has been delayed for unforeseen personal and technical reasons. We should have some available in the New Year. Apologies again.In the meantime here is a product which is available.

A Péchot bogie wagon kit is your invitation to join the 16mm club

16mm Wrightscale Péchot wagon kit made up. Courtesy MD Wright

You have bought a Wrightscale 16mm Péchot bogie wagon kit and are planning to convert it into a model. The humble original had an important place in the stoy of warfare. This means that you are making history and so you are part of something important. Once you have started creating this wagon, you have joined, if not a party, a movement. Craft is slow, gentle and thought-provoking. It allows you to focus on important issues. Best of all, it reminds you that there are other people out there who are having the same experiences.

Here are some thoughts about our experiences. When designing the kits, Malcolm immersed himself in the history. Where did the distinctive shape come from? Why does a simple push-me-pull-you shape actually contain so many asymmetries? It was part of a series. Why was this called the Péchot system? Why was it also called ‘artillerie 88’? Finally, does the Péchot wagon really matter?

Prosper Péchot (1849-1928) first wrote down his idea for a bogie ‘truck’ in 1882. He had clearly been thinking about it for a while beforehand. His Memorandum to the Ministry of 1882 was clearly very carefully thought out, with appendices and references to supporting work. This included experiments at the Decauville factory.

 This memorandum was his final thesis after his two years of study at Staff College 1880 to 82. It was generally accepted, even by his detractors, that it was a good, thorough piece of work. It was not welcomed at the Ministry, nor by the Génie – French equivalent of the Royal Engineers - because his ideas would cost a lot of money.

Prosper Péchot at retireent age. He has a Légion d'Honneur pinned to his chest. Photo courtesy Raymond Péchot

In the Memorandum, Péchot explained his theory snappily known as ‘the doctrine of multiplication of axles.’ As we know, the more points which support a load, the less each point has to carry. This is why 40-tonne lorries have all those extra axles – basically to save our roads. Unfortunately, all these extra wheels generate extra friction and so the lorries jack them up out of the way whenever the inspectors aren’t looking – and continue to make pot-holes. For a 19^th century French person looking for a way to carry heavy loads on earth or country roads, the friction was less of a problem. More axles were good.

The other part of the problem was how to ‘iron-clad’ bare earth or simple country paths. Prosper Péchot thought that one out too. In 1874-5, Paul Decauville of the Decauville Company started making his fortune with portable track and small carts to run along it. A cart running on light track laid on nothing more promising than muddy soil could carry 200 kilos. When they ran on rail, there was no problem transporting a load where it otherwise it was impossible to push a wheelbarrow. Péchot explored the Decauville ideas. He devised portable track which could support a mass of 3.5 tonnes per axle yes! fifteen times the tare of a Decauville buggy. In theory, just use more axles to carry ever greater mass. Four axles could support a theoretical mass of up to 14 tonnes. In practice, in order to support a 10-tonne wagon on light portable track, a bogie wagon was necessary.

This is a narrow bogie wagon built by Kerr, Stuart Ltd in the early 1890s. The design is symmetrical. Over in France, 10 years previously,  Péchot had shown that one side should not mirror the other. Illustration copyright MD Wright

Another innovation was needed. This was the way to link all these wonderful little axles together.  The bogie or ‘truck’ was already used on standard gauge. In places such as the USA and Festiniog Railway bogies were indeed already used on narrow gauge but they were fairly novel in France. Manufacturers such as Decauville were selling trains of small four-wheelers for use on their light agricultural and industrial railways. Péchot had to innovate here.

A sceptical Army expected to be convinced with the new portable track and bogie wagons but without having to pay for them. Paul Decauville helped out … for a while but by 1884, his patience wore thin. He was spending good money on innovation but receiving no orders in return. From late 1885, the Navy got interested. Then in 1886, the Press got on to the Army’s case. They believed that national security was being compromised. The French nation had paid out billions in today’s money building a string of forts to keep out any invaders. A new introduction, melinite, a precursor of TNT, made these forts obsolete. A dramatic artillery demonstration reduced a fort to rubble in an afternoon.

A typical late 19th century French fort was a hectare in extent, earth-sheltered and needed a garrison of around 600. A chain of them guarded the frontier. Photograph MD Wright

Something had to be done! What if you could move your guns out of the forts? Concealed in the woods and hills nearby, they could blast the enemy so vigorously that the fort itself never came within range. The Army turned back with relief to the ideas of Péchot. Trials in autumn-spring 1887-8 showed that a 60cm railway could rapidly be laid - taking guns out of a fort and up to a vantage for artillery, all in the space of a morning. The job could be done in time for lunch.  The nearest rival to 60cm, metre gauge, could not do this. The Ministry and the Press were convinced. The Army were obliged to follow their political masters.

In summer 1888, 60cm gauge was officially adopted and the 60 cm gauge wagon rolled out. Its official name was artillerie 88 because it was used by the French Artillery service and to mark the date of adoption.

This is the story of the Péchot plate-forme wagon and to us it is important. The more stories we share, the wider our common platform (so to speak). We should also like to argue that a Wrightscale kit offers you the precious gift of difficulty. In a fast-moving world, we need a little touch of slow.  Slick movementtends to drive us apart. Slow movement brings us together.

From instructions for Wrightscale 16mm scale Péchot 5 tonne bogie kit. Parts B and C may look the same but aren't, nor are E and G. Only one end gets N and make sure that Q is the right way up! Drawing courtesy MD Wright

The main difficulty for the model-maker is the lack of symmetry in what, at first glance, seems to be a regular and symmetrical object. You might think the bogie top would be a sort of box-lid. Beware! The bogie ends are not the same! The hangers used for fixing the axles are handed. The couplers are different. Even the safety chains are different and who could have thought that you could two sides to the same length of chain.

There were good reasons for these quirks and difficulties. As you work with them to create your model, you are joining the community of quirk and detail.

We can look more closely at what Péchot was trying to achieve. To create his platform wagon, he had made use of various technical fixes. Many were of his own devising; a number of patents were lodged in his name. The portable track might be laid on fairly rough ground. It often went round tight curves and tackled vertiginous slopes.  The standard 5 tonne bogie was at the heart of the system. It had to be able to carry 5 tonnes, balanced on a toy-like railway, often round the bend and up the wall, all without derailing. Strength had to be found in light-weight materials resulting from up-to-the minute technologies. 10mm steel plate was used, rolled and formed where necessary, steel castings where necessary. Many examples of this robust design have lasted to this day – over 120 years.

Battered, repurposed but serviceable, this Péchot wagon was over 100 years old when photographed. Courtesy MD Wright

At the bogie centre was a complex central casting that accepted the kingpin. This linked the bogie to the carrier above; sometimes a bolster, but more usually a ten tonne wagon body. The casting was held between steel plates and braced to the curved ends of the bogie by steel angle. The ends of these braces were fettled to steel angle that supported the bogie ends.

Another innovation was the draw-gear. Usually, a lightly made narrow gauge wagon would have draw-gear tacked to its end-plate. Péchot draw-gear was pivoted on the central casting through a shock-absorbing volute spring. The draw-gear could turn through a considerable radius – 45 degrees to each side of the centre line – without any sideways strain on the next linked bogie. Where bogies were simply linked through their ends, any sharp turn would risk derailing the next unit. This happened quite a lot on the Festiniog railway. As an intelligent ‘second adopter’ Péchot was determined to learn from their experience.

Besides having standard couplings, the draw-gear was equipped with side chains. This was typical of the belt and braces approach of Péchot design.

The bogie was not symmetrical, only having the compensated draw-gear at one end. The other, the tampon sec, also had draw-gear of a simpler sort which did not have the wide radius of ‘swing’. On occasion, the bogies were used as miniature wagons, pushed by hand. It was useful to make a train of them.

The bogie wheels also benefited from beautiful compensated springing. They could therefore ride out irregularities in height, those humps and bumps which were inevitable where track was roughly and hastily laid.

Best of all, each bogie had bevel-gear screw-brakes which operated on every wheel. The brake-wheel was located above the draw-gear standing well above the bogie platform and clear of the wagon. Alternatively, the brakes could be operated by a low-level handle if for some reason the brake-wheel had to be removed. During the First World War, simplified ‘Decauville 15’ bogie wagons were used; these had only one brake-wheel per wagon.

Wrightscale 16mm scale Péchot bogie wagon kit: stanchion. Seven were fitted per side and one at each end

Another thoughtful touch was found in the axle-box spring. As before mentioned, they were substantial affairs, part of a system of compensated springing. At the outer end of end was a substantial casting. Part of its job was to anchor the end of the spring. It also had a rectangular pocket, carefully orientated. This pocket exactly fitted a stanchion bar – the bars served two purposes. They normally secured the load to the wagon platform but one could also be used as a re-railing bar. Even a Péchot wagon might on occasion jump the track!

Wrightscale 16mm Péchot bogie kit. Back and front of the bogie turntable. The wagon body could rotate freely above.

The wagon body rested on the circular track visible on the bogie top, a sort of mini-turntable. Depending on the state of the track, the wagon body could pivot by means of rollers. The turntable-track was inward-tapere.

Although the Decauville Company had been working on wagon design for nearly twenty years, it took Péchot and his collaborators several years to perfect the design. By the summer of 1886, there were also six-wheeled bogies, each capable of carrying nine tonnes. By 1889, photographs show Péchot supervising Naval exercises where twelve-tonne (four-axle) bogies are in use. Imitation is the sincerist form of flattery. By 1889, the Germans had adopted 60cm gauge, producing their own bogie Brigadewagen and were well on their way to imitating the Péchot-Bourdon locomotive. During world war one, a system which its designer had seen as a weapon of attack had become an invaluable trench supply system for both Allies and Germans.

16mm Péchot bogie wagon made from a Wrightscale kit by Jim Hawkesworth. It is carrying a French gun of the period. Photo courtesy Jim Hawkesworth

The final question is a good one and one that craftivist should be happy to ask. Why bother? Aren’t there lots of other craft movements to join?

Everyone has a personal answer. You will have your own thoughts.

Here are ours. The Péchot system mattered a lot. It is an expression of France of the Belle Epoque, also an expression of individual genius. It is an innovation which had tremendous unintended consequences.