A REMARKABLE FLEET OF OLD STEAM WAGONS.
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Vehicles Still In Use After 19 Years' Work, Serviceable Parts Being Used in the Construction of New Similar Machines.
ASTEEL-TYRED steam wagon has become a rare sight in recent years, and it may come as a surprise to many to learn that a fleet of 21 steeltyred Straker steamers is still run by the United Alkali Co., Ltd. from their 'Bristol works. Most of these steamers are 19 years old, having been delivered by the makers the Straker Vehicle Co. in
1903. They were built at, Straker's Bristol works. The fleet includes both fiat lorries and tank wagons; one of the latter type being shown in our illustrations.
As the Strakerwagon has been obsolete for so long, it may not be out of place to describe it. It is briefly, an uedertype, with a compound two-speed engine driving through a chain, a watertube boiler being employed to generate steam.
The boiler consists of four cylindrical drums, forming two annular water spaces. These spaces are connected by short water tubes (about 570 in number). The inside drums are shorter than the outer ones, leaving below them a space, which forms the firebox. The inner drums Form, the stoking chute. The smoke and hot gases, pass round the water tubes to a smokebox on the top of the boiler. The chimney is at the front of this box.
As will be gathered, there are four joints to be made in this boiler, and these give a good deal of trouble unless jointing of extraordinary quality is employed.
At the bottom of the boiler is a superheater. Originally, the exhaust steam was superheated, in order to allow coropliance with the law with regard to the
emission of visible vapour. The exhaust superheater has, however, now been discarded.
As might be expected, with such a large heating surface, these boilers are quick steamers. Unless the water is quite clean, however, they prime badly, probably owing to the small water space. However, clean water is always. available in towns, and these wagons do very little country work.
The engine is compound with a start
ing valve. A single eccentric reversing gear is fitted. The engine is in a casing, but does not run in oil. It is rather inaccessible in the case of a platform wagon.
The cylinders are on the left-hand side of the wagon, but the crankshaft is carried across the frame, and the flywheel. is on the right-hand side, the pinions for the two speeds being between the frames.
The drive from the countershaft is taken by two chains working side by side on a double sprocket, and the crown wheel on the back axle is, of course, also double. The same idea is mum porated, it, will be remembered, in the final drive of the Scammell-six-wheeler. Truly, " there is nothing new under the sun."
The rear axle has the usual type of differential, which, however, is not, enclosed.
Gear changing from the cab is not possible. The driver must get down and walk to the side of the wagon in order to effect a change of gear. It should be noticed, however, that gear changing is never so frequently called for on a steamer as it is on a petrol vehicle.
The wheels are of steel and are, as before stated, steel-tyred. Some of the wagons have smooth wheels, others are provided with strakes. The front axle is immediately below the boiler, and is centrally pivoted, being carried on a cross-member bent to clear the boiler. Steering is by worm
and quadrant. This is rather an unusual type of front, axle for undertype wagons.
One of the disadvantages of steelstyred wagons is their inability to run on snowcovered roads. The United Alkali Co. have overcome this difficulty by providing spare wheels with rims of the type illustrated. Instead, of ordinary tyres, these wheels are equipped with a flanged Lyre. Rope is wrapped around the wheel between the flanges and each end is secured by means of a hook bolt. It is thus not necessary to withdraw all the vehicles from service during snowy weather. The disadvantage is that the ropes wear out very quickly.
The brakes consist of wooden blocks rubbing on the tyres of the rear wheels.
A pump for boiler feeding purposes is provided, being driven by an eccentric from a shaft revolving at, a lower rate of speed than the crankshaft. An injees tor is also fitted.
Other fittings include two safety valves. The pressure gauges were originally fitted to the bunker back ; but excessive vibration caused the pipes to break, and the gauges are now being fitted to the. boiler. One water gauge is fitted, and also a water lifter.
Lubrication is by oil cups and siphons. The cylinders are lubricated by an old type of bottle lubricator, which requires very frequent replenishing. An improved type of lubricator is now being fitted.
The tank wagons, which are used for the conveyance of acid in bulk are pro.
vided with a small two-cylinder pump for loading and unloading. This pomp, which may be seen in the photograph, is belt-driven-from the engine flywheel.
The wagons are quite satisfactory in operation, and are easily abls.to exceed the legal limit. They are intended for five-ton loads with -three tons on the trailer-, i.e., eight tons in all. Actually loads of from 11 to 12 tons are dealt. with, and the wagons perform this work without difficulty, even in muddy and soft yards, and without using the engine as a double high pressure except for starting.
From time to time wagons have worn out, and it is indeed a tribute to their satisfactory service that the company use the good parts of them in building new machines. The new wagons have stronger and stiffer frames; new bearings and a few other new parts are used, but, generally speaking, they are built out of old parts. The writer saw one of these wagons being built recently. The company acquired from the Straker Vehicle Co. their stocks of spares, etc., and are, consequently, in a position to do all their repairs and replacements without difficulty in the engineering shops at their Bristol works.
The trailers used in conjunction with these wagons are of the old-fashioned wooden type, and are fitted with spring drawbars. Besides the tank wagons and flat lorries there is a portable hand crane for loading heavy objects, but this has not been used lately.