Sevitame
1939 SIMCA - Sevitame, el anfibio francés.
SEVITAME Société d'Etudes des Véhicules Issus de la Technique Automobile Moderne et Economique
Alrededor de 1935 el Departamento Técnico del Ejército Francés ante la necesidad de un medio de transporte barato y confiable que le permita reemplazar los caballos por vehículos motorizados se interesa en una moto con características todo-terreno.
Las especificaciones incluían un conjunto motor que podía ser sumergido, ya sea parcial o incluso totalmente, transmisión sin cadena directa a la rueda. La moto debía ser silenciosa y se podría desmontar en pocos minutos en tres secciones para facilitar su transporte.Debía ser apta para la conducción en cualquier tipo de terreno y las partes mecánicas debían estar protegidas para ser capaz de cruzar arroyos. La moto debía subir sin esfuerzo ni sobrecalentamiento pendientes de 45°
Una cantidad significativa de aceite (ocho litros) circulando en el interior del motor debía garantizar una refrigeración perfecta, y permitir que el conjunto se utilice en condiciones de alta o baja temperatura sin peligro.
Velocidad normal: 75 - 85 km/h
Peso totalmente equipada: 120 kg
Capacidad del depósito: 20 litros
Autonomía: 500 kilometros
Cilindrada: 250 cm3 a 330 cm3
Es así que Marcel Violet y Achille Vincent construyen una motocicleta anfibia que solo pesaba 120 kg.
En 1938 se realizan pruebas en el campo de Satory donde la moto cruza charcos barrosos donde se hunde unos 40 cm., recorre dos veces sin dificultades una pista especial de prueba de tanques de 2400 km, atravesando zonas de cráteres y zanjas y remolca un coche averiado a paso de hombre.
La temperatura del aceite del bloque después de más de dos horas de uso a velocidades muy bajas (entre 2 y 8 Km/h) nunca excedió de 72°.
El proyecto aceptado y denominado Sevitame (siglas de “Sociedad para el Estudio de los Vehículos derivados de la Tecnología Automotriz Moderna y Económica”) es encargado a la fábrica Simca en Nanterre (en ese momento bajo la dirección de Amédée Gordini) que debería construir 3.000 ejemplares.
La Sevitame tenía un motor de dos tiempos de 314 cc. (62 x 52 mm), bicilíndrico en línea invertido (con el cigeñal arriba y los cilindros para abajo), refrigerado por ocho litros de aceite y transmisión final por árbol y un sistema de sinfín y corona. La alimentación era por válvula rotativa y un carburador Violet de 18 mm, encendido por magneto RG, caja de cuatro velocidades y embrague multidisco.
El cuadro eran dos piezas de chapa estampada abulonadas al motor portante que se desmontaban en pocos minutos retirando solamente cuatro pernos. El motor se podía utilizar en un bote como motor fuera de borda girando la toma de fuerza y acoplándole una hélice.
La suspensión delantera estaba montada en la columna de dirección mientras que en el guardabarros trasero contenia la batería, una caja de herramientas y el tanque de combustible de 20 litros que le permitía una autonomía de 500 kms.
Al fines de 1939 se fabrican un centenar de motos las que se envían a Polonia donde presumiblemente fueron destruidas. Luego de la invasión alemana, la fábrica fue ocupada y todo el material requisado. Cuentan que un operario de la fábrica se fugó con el único ejemplar existente para no ser capturado y luego lo donó a un museo.
Source: facebook.com/royal.panther.33
Société d'Etudes des Véhicules Issus de la Technique Automobile Moderne et Economique
5, boulevard de Italiens, Paris
In the mid 1930s the French Army's technical department, faced with the need for an inexpensive and reliable means of motorised transportion to replace horses with motorized vehicles takes an interest in a motorcycle with off-road capabilities.
The specifications included an engine assembly that could be submerged, either partially or even completely, and final-drive transmission by means other than chain. The machine should be silent, and it should be possible to dismantle it in a few minutes into three sections for easy transport. It should be suitable for traversing any type of terrain and the mechanical parts should be protected in order to be able to cross streams. It should climb 45° slopes without stress or overheating.
A significant amount of oil (eight litres) should ensure excellent engine cooling allowing operation of the machine in high or low ambient temperatures without problem.
Required specification:
Normal Speed: 75-85 km / h
Fully equipped weight: 120 kg
Fuel Tank Capacity: 20 liters
Range: 500 km
Engine Capacity: 250 cc to 330 cc
Marcel Violet and Achille Vincent fulfilled the requirements with an amphibious motorcycle that weighed only 120 kg.
In 1938 tests were carried out in a field at Satory where the motorcycle crossed muddy potholes as deep as 40 cm, navigated without difficulty a course which included craters and ditches designed for testing tanks and other tracked vehicles, and towed a disabled automobile.
The engine oil temperature after more than two hours of use at very low speeds (between 2 and 8 km/h), never exceeded 72°.
The project was accepted by the French military and was given the acronym of Sevitame, and the Simca factory in Nanterre (then under the direction of Amédée Gordini) was commissioned to build 3,000 motorcycles. [4]
The Sevitame had a 314cc two-stroke engine (62 x 52 mm), and was an inverted in-line twin (with the crankshaft above the cylinders in similar fashion to the Tiger Moth), cooled by eight litres of oil, and with 4 speed transmission via clutch to a cardan shaft driving crown and pinion gears. Induction was via a rotary valve and a Violet 18mm carburettor, with ignition by RG magneto.
The frame consisted of two pressed metal sections joined to each end of the engine which formed a stressed member of the chassis. The assembly could be dismantled in a few minutes by withdrawing only four bolts. The engine could be used as an outboard engine by attaching a propeller to the PTO.
The front suspension was mounted on the steering column while the rear guard was integral with the 20 litre fuel tank and also had compartments for the battery and toolbox. The bike had a range of 500 kms.
At the end of 1939 12 or 15 units [1] were manufactured and sent to Poland, where they were presumably destroyed. After the German and Russian invasion the factory was occupied and all material commandeered. It is said that a worker from the factory escaped with a motorcycle which is now the only existing example.[5] It is often ridden to vintage meetings by Francois-Marie Dumas.
M. Violet is not often mentioned in relation to motorcycles, but he was a major figure in French automotive history. He was one of the three founders of SICAM, the predecssor of Motobecane. He is credited with the development and popularisation of the two-stroke engine, he was associated with a variety of successful automobiles, and he supplied engines to the Bernardet scooter company.
A fine driver, he won Le Mans, and raced a scooter in the Bol D'or. A man of condsiderable complexity, his interest in natural science led him to study the reasons why gardens thrive so after rain despite being well-watered, and animals will seek out rainwater when tapwater is freely available. This resulted in the invention of a method for the electro-vibratory treatment of water (patent FR1142722), an apparatus approved by the French National Academy of Medicine in 1957.
Notes
1. One source says one hundred machines were built.
4. Elsewhere the figure is given as 40,000 rather than 3,000.
5. There are references to a machine located at Jackie Pichon museum at Cleres, near Rouen, now closed. It appears to be the same machine which belongs to M. Dumas, who writes that one of the two known machines was stolen in December 1980.
The patents are in the name of Achilles P. Vincent. The name Paul Vincent appears in a reference, so it seems likely Paul is his middle name.
An article on Sevitame appeared in Moto Revue no. 2017, 27th February 1971.
Sources: Sergio Scalerandi, moto-collection.org
Original article in French at appeldephare.com
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