Fodens, Limited.
Page 16
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Exhibit : —Two Standard 5-ton Wagons.
The two steam wagons on this stand are typical examples of the company's standard type. Each is capable of
carrying 5 tons, and of drawing an additional 2 tons on a single trailer, The makers, after considerable experience, are able to guarantee the capability of these machines to take full loads in very hilly country, and to take them up gradients as steep as i in 7 provided the roads are good. The Foden wagon has proved itself very economical in fuel and water consumption, and this has been attributed, by many people, exclusively to the use of a locomotivetype boiler. It is clear, however, that much of this economy is due to the excellent design of the Foden engine, which is steam-jacketed, and has its valves brought close up to the ends of
the cylinders, with resulting diminu tion of the clearances and volume of the steam passages as compared with many other designs. The company's boiler, none the less, is a fine example of good work : it is made throughout
of Siemen's mild steel, and is hydraulically tested to 35o1b. on the square inch, although the normal working pressure is 200lb. on the square inch.
It has so tubes of i inch in diameter, and is fed by two small injectors. These injectors are placed low down, so that they arc flooded with water from the tank, whilst an efficient straining-box is introduced into the feed-pipe imme diately before it divides to run to each injector. This intercepting box, which has the water inlet and outlet on oppo site sides, contains a vertically-removable drawer, with a handle at the top, and provided with flanges to overlap
the top of the intercepting box. The .bottom cf this vertical drawer, which is :placed en the outflow side, is formed of wire. gauze, and it effectually catches any dirt or particles in the feed water, whilst it can be easily withdrawn by the
removal of a few nuts. Examination -discloses the fact that the fire-box has been made specially large for easy steaming, whether with coal, coke or wood as fuel, and the total heating surface in both fire-box and tubes is go square feet. The horizontal-compound engine, which is mounted, with all its motions, on the top of the boiler, according to standard traction-engine practice, has cylinders 4 inches and 61 inches in dia
meter, whilst the piston stroke is 7 inches : the driver can see the connecting-rods, crankshaft, etc., continu
ously. Prevision is made for giving high-pressure steam direct to each cylinder, in order to secure extra power for emergency work or the climbing of exceptional inclines, and each cylinder exhausts independently of the other at such times. The exhaust is conveyed into a silencing and superheating chamber, carried in the smoke-box, and this has proved a very useful fitting in practical work, as it both muffles the separate pulsations of the engine, and tends to prevent the emission of visible vapour.
The system of transmission consists of sliding, cut-steel pinions on an extension of the crankshaft, one of which is made to engage with corresponding gear wheels on a short " stud " countershaft. A long chain, of the Hans
lien old roller type, conveys the drive from a small chain-wheel, which is carried between the two spur wheels on this countershaft, direct to the differential gear on the live back axle. This transmission Combination is arranged to give a reduction, as from engineshaft to road wheels, of g to i and 24 to i, which corresponds with vehicle speeds of about 2t, and 6 miles per hour at normal engine revolutions. Each radius rod is in the line joining the centres of the two chain-wheels, the fact that the smaller of these is on the tap of the boiler, rendering it possible for the forward end of the rods to be secured at points on the main frame about midway the length of the chain.
The frame members are of channel section, 6 inches by 3 inches by ,4 inch, and they are drawn together at the front to make due provision for the attachment of the boiler, which itself forms an efficient stay for the front of ' the vehicle. This feature, in which the engine is carried, practically, as though it were a horse between a pair of shafts, is one of the several unique features of the Foden design. Suitable cross-stays are used in that portion of the frame which lies behind the boiler, In order to secure the necessary bracing effects.
Steering gear of the traction-engine type is employed, and the front axle is centrally pivoted, whilst the ends ot
the inverted laminated springs which are involved in its desig-n, are provided xeith suitable slippers where they travel on the front axle. The degree of movement imparted to this axle by the movement of the steering wheel is sufficiently quick for handy manoeuvring., and is much quicker than was the case in the Foden wal,on some years ago. All joints in the steering connections are covered, so as to keep them free from mud and dust, and the usual precaution has been taken by the makers to take up vibration by the introduction of small spiral springs between the front axle and the ends of the steering chains.
The company's address is Elworth Works, Sandbaeh, Cheshire, and visitors to this stand will be able to peruse a large number of interesting testimonials from users in different parts of the country whosn experiences have extended over a long period of years. It will be noted, too,' that the system embodies the best points of traction-engine design, which make for satisfactory and economical running in practice.