Friday 9 March 2018

The Péchot system and 16mm scale



We are looking forward to seeing friends old and new at the National Garden Railway show in Peterborough on April 7th. We recommend a look at the Show website, ably curated by Richard Huss.
We are hoping to bring back a series of kits which celebrate the Péchot system. This was a vital part of military transport during the First World War, and for some years afterwards. From 1888 it had been a staple for the French Army. When the vast networks of 60cm railways that served the trenches were sold off, 1919-25, the French kept their Péchot locomotives and rolling stock for military use.
A Péchot wagon has been preserved outside Fermont, a part of the Maginot line. Until 1940 it had been used by the French Army. Photo 2005 S. Wright
Now at last, these wagons and bogies are finding their way on to preserved railways in France and across the Channel, so the enthusiast can enjoy and become familiar with the prototypes. Alas, only two locomotives survive, in transport museums in Dresden and Serbia, but there are a fair few wagons.
We are planning to re-release our 16mm scale kits for wagons and cranes. We thought this might not be possible - our well-respected white-metal caster Adrian Swain heads for a well-deserved retirement. Fortunately, with the help of a new caster and other sources of material, we hope to put the Péchot system back on your rails!
Fine 16mm model by the late Henry Holdsworth features a Péchotwagon in th eforeground with WD rolling stock. Picture courtesy Jim Hawkesworth
This design of bogie was the first project of my hero, Prosper Péchot, the basis of his celebrated Péchot system in 60 cm gauge. The first version of this system was described in a memorandum of 1882, eleven years after the Franco-Prussian War. The essence of his plan was to bring massive bombardments on the heads of the detested Prussians; an ambition shared by his military colleagues. Unfortunately for the French Army, short of building a standard gauge railway under the noses of the Germans there seemed no way of bringing big guns and quantities of ammunition close enough.
The secret of the system? Prosper Péchot took advantage of new technologies, science and experimentation to devise a portable railway. According to his calculations, the French army could extend such a railway several kilometres from an existing railway and have it near enough to threaten a German position within a few days.
Parts of a Wrightscale 16mm scale Péchot bogie. It ran on four wheels. Each axle could support 3.5 tonnes. Two axles could support in theory 7 tonnes but the loading was rated for safety at 5 tonnes.
 Science and trials in a Decauville factory demonstrated that a locomotive could run on 60 cm gauge. Yes, his plan was to create a railway a mere TWO FEET in gauge consisting of lengths of portable track. Each was light enough to be carried by a team of four. Admittedly, there was a lot of improvisation in those first trials, using whatever Decauville could provide. Péchot proved a principle: each axle could support a loading of 3.5 tonnes on this specially designed track and four axles together could support 14 tonnes. This was enough for a proper locomotive, and for a train of freight - as long as the wagons were supported by a sufficient number of bogies.
Spring pin from a Wrightscale Péchot bogie kit. This modest component could be used as a rerailing point
Like the prefabricated rail, the bogie had to be robust yet light enough to handle. A single bogie could carry a load of 5 tonnes on light rail. Not only could these run on an unpromising permanent way – a muddy farm track would do at a pinch – but also they could be re-railed by a couple of operators using materials to hand.
Stake from a Wrightscale Péchotwagon kit. This dual-purpose item could be used for load-retention but also as a rerailing bar.

At the time, this was all ‘cutting edge’ Steel of the quality and quantity required was only recently becoming available. Press tools capable of stamping out components from the new steels were also recent introductions. The idea of wagons running on bogies only went main-stream some years previously. For example, the celebrated GWR of Britain only introduced bogie wagons in 1873 (source wikipedia entry on GWR).THere wasn't even a French-language word for the bogie. It was often called 'wagon' or 'truck'
Péchot gathered ideas from around the world. He owed much to Paul Decauville who introduced a workable system of portable railways to industry and agriculture. He took an interest in the Festiniog railway, also the Darjeeling Himalaya Railway and there is evidence that he looked at logging railways of the USA. He felicitously combined them into something unique.
Trunnions from a Wrightscale 16mm crane kit, used to link bogie with wagon or in this case a rail-mounted crane. Péchot called it a 'turntable'. This link was totally flexible - useful on a winding track.

He did not go for officially sanctioned narrow-gauge. At the time, only metre gauge  was permitted for goods and freight in France. French government policy was to requisition what was available in time of war rather than to have independent military transport. As metre gauge networks spread out around France, so the confidence in using this version of narrow gauge spread. Péchot was therefore considered a maverick and a potentially expensive one.
Péchot wagon pictured on the Apedale railway by Jim Hawkesworth in 2014. Though shorn of its loading stakes (and other things beside) the wagon looks pretty good for its 115 years.

In order to introduce his system, he all but sacrificed his career. Once it was officially adopted in 1888, the French Army used it though it was fairly run-down by the early 1900s. The Prussians, however, who had been flirting with other gauges suddenly adopted 60cm for themselves. The date? 1888. Bogie wagons equally appeared. Coincidence? No. They knew a good thing when they saw it.
You might like to read:
Bailly, Roger ‘Decauville, ce nom qui fit le tour du monde’
Cénac, Dr Christian 60 cm pour ravitailler l’Armée francaise 14-18 (both French language)
Dunn Richard ‘Narrow Gauge to No Man's Land’
Wright Sarah ‘Colonel Péchot: Tracks to the trenches’ (story and pictures in English)


Wrightscale 16mm Pechot bogie non-slip decking. Before the days of Health and Safety, the designer thought about the welfare of the soldier. Shifting heavy weights in frost and rain was hazardous enough


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