Alexis Hallette

Born with Lille, but originating in Heuchin, Alexis Halette (1788-1846) with Arras in 1812 settles. His/her father, manufacturer of wire and laces, gives him the taste of mechanics. True precursor of modern industry, it joins Crespel-Shreds by designing the first machines for the manufacture of the beet sugar.

It installs in Arras of the workshops covering more than two hectares and employing 800 workmen. It improves a number impressing of machines in very different fields: boilers, dredger, hydraulic press for the mills with oil, steam engines, and finally, it is interested in the railroad.

In 1829, when two engines built by Stephenson in Newcastle enter to France, one is entrusted to the brothers Seguin in Lyon, the other in Alexis Hallette. It produces initially only spare parts. It should be waited 10 years so that its workshops the first engines for the Company of North leave. It improves them and, to avoid the movement of so unpleasant lace on the first railroads, it brings closer their cylinders.

In 1842, it organizes its workshops to produce there twelve engines per annum at the cost of 48.000 francs part. First in Arras on August 3rd 1845 is tested. It receives also the ordering of 16 engines on behalf of the Company of Montereau-Troyes. Only one is currently preserved, it acts of the " Sézanne" visible with the Museum of the railroad in Mulhouse. This engine with only one driving wheel circulated of 1848 to 1871.

Whereas Marc Seguin develops the tube boiler which multiplies by ten the production of the vapor, Alexis Hallette takes another route. At that time, three systems of locomotion on rail clash; the tractive system which comprise fixed steam engines drawing the coaches by cable, the locomotive system which finally carried it and the atmospheric system. This system does not include/understand any more an engine, but a tube 0.50 m in diameter, placed between the rails and where a piston is in front of which one makes the vacuum and which moves thanks to the atmospheric pressure. This piston is connected to the axle of the coach by an iron stem which slides by a longitudinal opening spared in the upper part of the tube. But a problem arises: how to preserve the tightness of the opening giving access to the stem? Hallette spends eight years to solve it. In 1843 it finds a process very simple: the parallel edges of the propellent tube are provided with artificial lips. Its lucky find is then greeted as revolutionist. A commission of experts concludes with the superiority from the atmospheric system which removes, in the convoy, half of its weight consisted the engine and the tender. Moreover, the fire hazards are eliminated, the cost of the railroad in is reduced. But the English also work on this project and Hallette which knows money problems must be resigned to sell its process to them.

He dies on July 3rd 1846, with the return of a voyage in England where an English company carried out tests on its invention.

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