Gas-driven Chassi.
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kmongst Prominent
FEATURES OF r
EE PARIS SHOW
THIS year's Paris Salon is, indeed, a queer one. Although in the touring-car section there is an atmosphere of cheerfulness and the public attendance is remarkably good, matters are rather different on the commercial vehicle side. This section of the Show is being held under a threat of immediate super-taxation framed to protect the newly formed State railway combine. How serious is this menace may be gauged from the statement that, if certain proposed legislation be carried through, hauliers will soon find their annual taxation trebled.
This is only one aspect of the matter, for the French industrial-vehicle user is being shot at from every angle— by drastic new regulations affecting the conduct of Ids business, and constantly increasing indirect taxation, levied on motor fuels, lubricating oils, and other basic necessities. Even the British operator, harassed though he may be with masses of red tape, may count himself fortunate not to be operating in present-day France.
In these circumstances, it is not surprising that few mechanical changes are to be found in this year's Salon, constructors preferring to mark time until the clouds roll by. The wonder is that this Show should be the really good one that it undoubtedly is. There is much of interest to be seen and, in two directions, progress is strongly marked. These lie in industrial coachwork and the adaptation of engines to the employment of fuels other than petrol or oil.
Amongst the heavies, gas-driven chassis are to be found on almost every stand, arranged either for the use of solid fuels in producer-gas appliances, or for compressed town gas. The latter fuel has, of late, made remarkable strides, and gas filling stations are springing up rapidly all over the country. In the gas-producer world, the Gohit,Poulenc B12 appliance would appear to have conquered most of the French market. Panhard-Levassor and Berliet employ their own systems, but Latil, Unic, Laffly, Somua, Renault and others, all use the Gohin-Poulenc, each company making suitable adaptations to the requirements of its own chassis.
The latest Gohin-Poulenc generators have water-cooled air nozzles, supplying air to the furnace. This is an important modification as, by this means, air can be taken right to the centre of combustion without fear of melting the nozzle. A radiator and small water tank for the injection circulation now form part of the Gohin-Poulenc ensemble.
Apart from this, one interesting improvement to the machine has been brought in by Unic. • In the G.P. gazogines, as built by Unic, a vacuum-operated air valve governs the quantity of air supplied to the generator. In operating vehicles on producer gas, one of the most important considerations is to keep a steady fire burning in the generator furnace at low engine speeds, and some form of hand control to the air supply is always fitted.
In the Unic appliance, a small vacuum cylinder is arranged at the outer end of the water-cooled air injector; this is connected by pipe-line to the induction manifold. A spring-loaded piston in this cylinder opens or closes the main air valve under engine suction. When the main valve is closed, air can still enter through a small, central tuba in the injector, the amount being just sufficient to keep the furnace going steadily.
Used in conjunction with the special mixing valve on the engine, which is another Unic-G.P. iniprovement, excellent acceleration and great engine flexibility are claimed.
Delahaye is another concern using the Gohin-Poulenc apparatus, and an example of its 3 ton gas-driven chassis is shown, for which the following claims are made: —50 m.p.h., maximum speed on the level, with 2.7 tons useful load; 25 m.p.h. maintained on 6 per cent, gradients; running cost on charcoal fuel-19 francs per 100 km. (about 2s. lid. per 62 miles, at the present rate of exchange!). All these important French Concerns now build special power units designed for gas fuel; it is no longer a matter of adapting petrol engines. Such power units usually have about 44 per cent, greater cylinder capacity than their petrol counterparts. Latii has developed the gas side of its business strongly, and displays many chassis with the G.P. generator. In addition, it has a number of municipal vehicles designed to run on compressed town gas. • Compressed gas has manifold advantages as a fuel, but its installation on a 'vehicle is dnfortunately cumbersome and heavy. Eight or 12 gas cylinders take up as much room as the portable gasworks incorporated in a generator and filter, with its attendant pipe work, whilst the collection of gas cylinders certainly weighs a great deal more than a producer outfit.
Most of the town gas-equipped lorries exhibited carry the cylinders on brackets, extending from frame sidemembers, but one Latil model has them arranged transversely in a compartment at the back of the driving cab.
Renault industrial models are unchanged for 1939. with the exception of the A.F.P. 1-tonner, which now has long, flat springs at the rear instead of the transverse spring
formerly employed. Renault presents, however, an entirely new light delivery model, which, with its low fuel consumption, should certainly become popular. This sturdy little chassis, which is intended for 5-cwt. loads, has the same type. of engine as the Renault Juvaquatre, which has achieved such remarkable success in the French touringcar, world. It is a four-cylindered unit, with dimensions of 59 min. by 95 mm. and gives 23 b.h.p. at 3,500 r.p.m.
This little Renault is to be known as the " 250 " model, and it is exhibited as a light delivery van, on particularly stnart and attractive lines, with remarkable loading
capacity for the chassis size. Catalogue claims for performance are 50 m.p.h. maximum under full load, and a fuel consumption of only 7.5 litres per 100 kilonis. The efficiency of the Renault juvaquatre engine is such that this claim should be borne out in regular service. .-Transverse springing is employed in this 'chassis, independent suspension being provided for the front wheels. Messrs. Coder, the French trailer specialists, have au interesting exhibit in the form of a " container " for road and rail transport. This is a 7i-ton semi-trailer unit, in which an idea has been borrowed from aeroplane design. Whilst the ordinary container is simply lifted clear of the
lorry or trailer upon which it has made its road journey, the new Coder, known as the Seremcoder, when being placed on a railway truck, is elevated as a unit ready to be hauled away on its arrival at the end of a railway journey. This is arranged hy making the wheels of the trailer retractable. • They are wound up by hand-operated gear into the interior of the body, just like the " undercart " wheels of so many present-day aeroplanes. The operation takes only a few minutes.
Another useful feature of the Seremcoder is that the wheels can be manipulated independently, also by
hand-operated' winding gear. This should be a boon when manceuvring the tractor-trailer unit into position beside its truck in a congested railway depot. The special girder-form drawbar of the Seremcoder is made detachable, as such confainers are liable to be hauled by a variety of tractors when arriving at the end of their railway journey.
French industrial coachwork has, of late, made great strides, and some of the commercial bodies to be seen in the underground section of the Grand Palais Would compare favourably, with those of any automobile-producing country in the world. In going. around this section of the Show, where complete vehicles are staged, one receives a surprise now and again, • as French chassis constructors • allow industrial coachbuilders to claim credit for a complete vehicle.
For instance, one may sec a fine 36-seater, Gardner. engined La.til coach with " Floriat " on the iadiator: On inquiry you will be told that this is a FlOriat body mounted on our own oil-enginecl Florist chassis,
An interesting exhibit in this underground world is the Gar-Wood-Lagache et Glaszmann rear-engined coach. This has a Ford V8 .engine and gearbox mounted at the rear. Side panels of the 30-seater body are* in aluminium alloY, whilst the ends a:•-e single steel presiings ; the idea is to facilitate repairs should panels he damaged. The Isobloc Co. of Paris specializes in this system of construction.. '•
In the matter of British representation, Rootes, Ltd.; • shows Karrier machines, which have made considerable progress on the Continent, whilst the Gardner concern seems to have a large proportion of the oil-engine world to itself, such units being built under licence by many of the most important heavy-vehicle companies in France..
French tractors, of the three-wheeled type, are shown by the Ste. F.A.R., a subsidiary of the Chenard and Walcker Co. These tractors employ Citroen industrial engines, and 'an example worth examining is the s-ton semi-trailer F.A.R. unit with the big Citroen engine designed to use compressed town gas. This is a well-designed and soundlooking outfit.
Sovels have the. only electrics in the Salon, and in these days of intensive taxation, and high fuel costs, the firm are reaping the reward of consistent good work, especiallY in the many parts of France where cheap electricity is available from ,water power. Roehet-Schneider presents two new models, a worthy effort in view of the difficult times. The most important model shown is the Phebus chassis, designed for a 42-seater coach. This has a sixcylindered 8.58-litre oil engine, delivering 115 b.h.p. at 1,800 r.p.m.
An industrial-vehicle accessory, which would. appear to be making headway in France, is the S.A.F.E. electromagnetic transmission brake, now offered as an optional feature by fink, Saurer, Chenard-Walcker, Bernard, Somua, Latil and other French makers.'
Apart from its smoothness in action, one of the chief claims made for this auxiliary brake is that it can be used indefinitely without wear of any kind taking place. There is no element of friction, apart from the negligible amount in ball bearings, as moving parts do not make actual • contact. It follows that, if such a brake be employed when descending long gradients, a great saving in wear and tear on brake facings is effected.
The action of the S.A.F.E, brake is based on what are known as Foucault currents—currents induced in a mass of metal when rotated in a magnetic field. In the S.A.F.E. design, a steel disc is allowed to rotate between the opposite poles of a number of eleetro-magnets. The periphery and hub of the 'rotor are_ provided with blades for cooling purposes, air entering and leaving the appliance through orifices in the aluminium casing which houses the magnets or inductors. The rotor shaft turns constantly with the • transmission, and there is a clearance of 1.5 mm. between the magnet faces and the rotor disc..
As As there is nothing. fragile about the :rotor, it would be capable of withstanding high temperatures, but, in actual .,fact, it is said never to rise beyond 70 'degrees-80 degrees C. The inductor coils are excited by the batteries on the vehicle and the current naturally varies according to aI5 intensity of braking action required. In the case of really heavy duty lorries, an auxiliary brake of this kind must, obviously, be of value. Amongst municipal vehicles, the Rey and Genere systems of self-loading for domestic refuselorries appear to be about equal in popularity and both systems have, from time to time, been fully dealt with in this journal. Paris, at the moment, has 360 Rey self-loaders at work, and about the same number of Generes. A fire-fighting machine, much in favour with country town brigades, is the small Laffiy trailer pump. This is a useful tittle outfit ‘ihich can be hauled by a small car, or even by a motorcycle combination. The arrangement comprises a Laffly four-cylinclered 65 mm. by 75 mm. engine and centrifugal pump, mounted on a two-wheeler trailer. The pump has a normal output of 70 cubic metres, but can be forced up to 80 cubic metres; the weight of the complete outfit is just over 9 cwt. The Latil snowplough attracts much attention, as more mountain roads are steadily being kept open, throughout the winter, with the aid of these machines. The ensemble comprises a Latil four-wheel-drive tractor-lorry chassis, with a 70 h.p. auxiliary engine mounted upon it to drive the rotary excavator wheel. This four-bladed wheel is 10 ft. in diameter and turns at 60 r.p.m. On the front of the vehicle is a Vee snowplough of normal type and controls, including steering wheels, are duplicated, the two drivers sitting face to face. More than 200 of these machines are already in use, by the French Roads Dept., in the Alps and Pyrenees. The Salon remains open until 8 p.m. on Sunday next, October 23.