Big guns and tracks to the trenches

Artillery has been at the heart of modern warfare. Indeed, if the vast catapults of Roman times and the throwing spears, arrows etc of ancient time are included, artillery has always been important. France of the 1850s and 60s thrilled to stories of big guns. The young Prosper Péchot idolised his uncle who went out to free Italy from the yoke of the Hapsburg oppressor. At the battle of Solferino, the French Army under Emperor Napoleon 111 hammered the Austrians at a safe distance, thanks to their modern guns. A panorama showing the guns was painted and put on exhibition, to the delight of vast numbers of the patriotic French.

Sketch of the battle of Solferino 1859 from a painting by Meissonier. Copyright MD Wright

It is easy to imagine a young Péchot deciding to become an officer in the Artillery on the strength of this victory. Before he could join up, he had to win a place at the prestigious Ecole Polytechnique. This involved two years at a junior university before he could even sit the competitive entrance exam, but he managed all this and in 1870 was a student there, sponsored by the Army.

‘Bigger, better, faster, longer’ was the slogan where artillery concerned. Unfortunately, the French took on Prussia in 1870. Undoubtedly their new rifles were superior to the Prussian offer and there were many German casualties. The Prussians, however, had superior guns. There were also other factors in the French defeat. Too many of their trained army were pinned in frontier fortresses or interned in Switzerland. Enthusiastic citizen armies were no match for the well-drilled Prussians who always popped up in the right place at the right time – the most inconvenient place at the most inconvenient time from the French point of view.

Prosper Pechot in 1909. Courtesy of Raymond PECHOT

There were many lessons learned from the humiliating defeat followed by the loss of Alsace Lorraine. Bigger and better artillery was one, bigger and better forts another.

For years after, standard exercises at officer training were re-runs of the 1870-71 war. In 1882, Prosper Péchot, now in training as a staff officer, was set a problem: How should he recapture the city of Metz from the Germans? (Metz was one of the prizes that were awarded to the Germans in the peace of 1871.P Péchot‘s response was non-standard, and made history.

The standard Prussian gun used in 1870-1 used 4 kg shells. The Germans had difficulty in transporting sufficient of these comparatively small shells to their gun batteries. By 1914, their mortars could be firing shells of 40 kg. An efficient means of transporting shells was needed. Copyright MD Wright

He realised that the only practicable way to bring the big guns within range of the enemy was to bring them up on temporary railways. There were already examples of this technology. The Decauville Company had been marketing portable track since 1876s. By the late 1870s, they were in use on military bases.

In 1880, Paul Decauville, thought of using his portable track for transporting guns and ammunition in the field. Until then, such track was considered only suitable for light little wagons, and stacks of shelves, for smallish loads of gravel, earth or agricultural produce. It was unsuitable for large loads; worse still, using a horse to pull the wagons along tended to wear away the margins so that bit by bit the rail was dislodged. Thus when Decauville track was used on campaign in Tunisia, it attracted much criticism.

The genius of Péchot was to design away every difficulty. Track and axles were the first part of his problem-solving approach. He determined that 60cm gauge (0m60 as he preferred to call it) was the best compromise between standard gauge which gave stability and speed and very narrow gauge which could be easily laid.

He then improved the track. Existing Decauville track could best be described as metal ladders, quickly laid, quickly taken up, but quickly mauled. Péchot devised the track anew. Not only was there a heavier weight of rail and more sleepers per prefabricated length, but each of these sleepers extended well beyond the rail and was cleverly designed to keep the ballast under it. By careful use of theory and practice he made sure that each 5m length could be carried without strain by four men. His Memorandum of 1882 is accompanied by a sketch of his new design.

Pechot's 1882 Memorandum to the Minister. Big guns need new technology. Courtesy Raymond PECHOT

Péchot also found the way to carry hitherto unimaginable loads on this light portable track. Okay, each wagon axle could safely carry a maximum of 3.5 tonnes (itself quite an advance) but what about having lots of axles under each wagon? This could double, quadruple yea, dodecatuple the load that could be carried.

This technology was very new, but in 1882, Péchot was already designing improved bogie wagons. He realised that the axles had to be joined with efficient springing and made advances there. To accompany his Memorandum, he provided a sketch of a 270mm gun being carried on a portable railway.

Horses and oxen wore away the tow-path. The more effort a beast of burden put into pulling a wagon forward, the more it scraped away the path – simple physics. Once the tow-path was eroded, the entire railway started tipping into the hole thus created. Don’t blame Isaac Newton for his Second Law of motion – that’s like shooting the messenger! Once the tow-path was eroded, the entire railway started slipping into the hole. The worse the hole, the more the poor beasts had to pull and the more they eroded the tow-path. 

Péchot was not the first to solve the problem. If the prime mover was itself using the track, then the forces were resolved into the track in relative safety. He was the first to insist on locomotives being the rule not the exception. His Memorandum of 1882 shows a 5-tonne Decauville locomotive equipped with steam capstan hauling the gun.

The standard Pechot system well-wagon, manufactured 1888 and in use until after the Second World War. This was photographed outside the Maginot fort of Fermont by SM Wright

After a struggle ending with convulsions in the French Army, the Péchot system was officially adopted. feldbahn. The Brigadewagen was similar to the standard Péchot wagon, both in having bogies and in overall length.

Wrightscale 16mm model of a Pechot well-wagon

Interestingly, the French Navy used it to best effect. This was in 1888. That very year, the German Army stopped its flirtation with other gauges and settled on 60 cm for its own

 When designs for Mallet and then Péchot-Bourdon locomotives appeared, the Germans ditched their Hohenzollern locomotives and started producing ones of similar appearance and weight. The Germans also kept improving the designs and so by 1914, they had benefited from over 25 years of R&D.

French 155 Long gun as used in 1914-18. Photographed at Verdun by SM Wright

The French kept to the old-fashioned idea of long-barrelled guns and their field railways were adapted to transport them. The Germans standardised on mortars. These could more easily be moved by horses or a team of men. Their wagons was used for ammunition and all the other stores. The Brigadewagen, though an admirable design in many ways, was therefore lighter and less durable than the French (and later the British WD bogie wagons). There are few survivors.

The German 105mm mortar was less of a brute to transport but it was of high calibre and generally able to inflict a lot of damage  on the trenches of the enemy. Photographed at Verdun by SM Wright

The Péchot well-wagon is so sturdy that numerous examples survive. It was, however rather over-engineered. In 1915, the French Army introduced the ‘Decauville 15’ a somewhat lighter wagon but produced in thousands.

A ‘Tracks To The Trenches’ event is coming up at the Apedale Railway. Among many other goodies, there should be an example of the Péchot well-wagon and of the ‘Decauville 15’ Catch it 13th to 15th July.

For the full story of the Péchot Memorandum of 1882, see Chapter 111 of ‘Colonel Péchot: Tracks To The Trenches’ Birse Press.

The Decauville 15 platform wagon did not have the handy well of the Pechot wagon but it was easier to manufacture. This survivor was photographer in the museum at Verdun by SM Wright

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