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FIGHTING FIRE RURAL AREAS.

7th November 1922
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Page 16, 7th November 1922 — FIGHTING FIRE RURAL AREAS.
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Which of the following most accurately describes the problem?

Districts Where Fire-Fighting Appliances Protecting Country Mansions. Pump Eqi Outfit.

it or Totally Inadequate. The Problem of r Light Tenders. The Scope of the Trailer ye Costs. IiN SPITE of the great progress which has been made in equipping our larger towns with satisfactory fire-fighting appliances, there are still thousands of places which have either very poor equipment or none at all. This applies particularly to the smaller villages, and cases are known illiere the nearest fire-engine (one worthy of the term) is twenty or more miles away.

There 'here are also hundreds of country mansions, far removed from any big gatherings of human habita, tions, which are absolutely at the mercy of the fire .fiend when a conflagration breaks out.

The secret of successfully combating fires is to commence operations -against them at the earliest possible moment. Outbreaks can often be checked or extinguished by the ordinary type of portable extinguisher, but this can only be done if such an aid be employed before the fire has been able to obtain • a grip. Many occur in the night hours and may not be noticed until they a-re well under way. If the fire pumps have to be fetched from, possibly, several miles away, it is highly probable that aconflagration which would have required only a small engine if tackled immediately, could not be extinguished by half a dozen of the most powerful pumps before irretrievable damage has been done.

Even in those sparsely populated areas where Ereengines are available, the latter are often ancient ruins which are almost ineffective in dealing with any but the smallest outbreaks.

Up to the present the great iiifficulty has been the "comparatively high cost of satisfactory apparatus. The modern fire-engine may coSt anything up to 22,000, and one can hardly expect a village to he able to find the funds for such a machine, although a certain amount of good work has been done by the puichasing of satisfactory equipment on a cooperative basis, where several villages have joined together and bought a suitable fire:engine which is available for the whole district.

What is really required is an efficient motor pump marketed at a price so reasonable that it will appeal even to the smallest communities and for private estate work. Such equipment, is manufactured by Dennis Bros., Lid., of Guildford, whose experience in motor fire-engine work is second to none. The company were established in 1895, before the passing of the Light Locomotives Act, and they were the first builders successfully to adapt the turbine pump to motor fire-engines, the first machine being supplied to the Bradford Brigade in 1908.

The latest development in this connection is a two stage turbine fire pump, which bids fair to become one of the most popular types in the country. It is woralerfully compact for is output, completely

balanced, has practically no wearing parts beyond the bearings of the main spindle, can be automatically primed in a few seconds, and is thoroughly soundly constructed in non-rusting materials, except for the central spindle, which is protected from the• water by a phosphor-bronze sleeve.

The pump is made in three sizes : (1) Capacity 150-200 gallons per minute, in two types, the ordinary standard with straight-through drive, and a special model, combined with a gearing-up device, which is used in conjunction with slow-speed engines • (2) Capacity 200-250 gallons; (3) Capacity 300-35k) gallons. The smallest type is priced at £120 fox the pump alone, arranged for direct coupling, or L135 equipped for slow-running engines, such as the Ford; complete with brackets for the Ford, the cost is 2145. The 200-250-gallon model, fitted on to a trailer and provided with a four-cylinder petrol engine, costs 2450 if the trailer be equipped -with solid tyres, or 2402 if equipped with pneumatics and suitable for trailing behind a motor vehicle. Although nominally termed a 200-250-gallon appliance, this model can pump as much as 350 gallons per minute, if required, at useful fire brigade working pressures, which gives two, three, or even four useful jets which can be brought to bear on conflagrations.

The trailer unit is particularly neat. It has a fourcylmder monobloc engine of 80 MM. bore and 130 mm. stroke, directly coupled to the pump through the medium of a single Hardy disc joint. It is equipped with a hand brake which is operated from the rear and consists of internal-expanding cast-iron shoes working on steel drums bolted to the wheels. At the rear is a pivoted leg, with a spring bolt for locking it in the up and down positions. A second leg is provided.at the front and is, when not in use, held up by a spring clip. An eye for towing purposes is provided at the front, and also detachable handles for nisnual haulage. The outfit includes 20 ft. of suction hose equipped with a suitable copper strainer.

The solid-tyred trailer is not recommended for tow

ing •behind motor vehicles, but a trailer fitted with pneumatic tyres can be drawn at comparatively high speeds, as it is well sprung. The two-stage turbine pump, which is protected under patent No. 146,208 and manufactured entirely in the Dennis factory, is so novel that it deserves a detailed deseription. its general design and the way in which water passes through it can be observed from the photograph of the sectioned pump, which we reproduce. The pump proper consists of a front and back cover, a stationary diffuser ring and two impellers carried on the central spindle, one at each side of the diffuser ring. Ancillary to the pump is an exhauster pump in duplicate, which -creates the necessary vacuum in the turbine pump and suction hose and causes the water to enter the pump, after which the exhauster plump is thrown out of action. .

Referring to the illustration of the sectioned pump, the water from the inlet passes to the centre of the first impeller and is projected by it into suitable channels in the diffuser ring, whence it passes over the last-named and to the centre of the second impeller, from the periphery of which it returns to

the other side of the diffuser ring, although by different channels, and travels thence to the deliveries, of which there are two, either one or both of -Which may be utilized. The diffuser ring in shown separately in another illustration, and the different channels by which the water enters and leaves the second stage impeller can also be seen.

The provision of two impellers placed back to hack permits perfect balancing, and there are no parts in actual wearing contact except the main bearings. The centre of the diffuser ring and the sides of the front

and back plates, where these almost touch the outwardly projecting parts of the impellers, are lined

with white metal in order to form water seals at these points, but there is no actual contact. The normal speed of the impellers is between 1,600 and 1,800 r.p.rn. The twin exhauster pump is of very simple and sound construction ; its pistons are of aluminium

provided with two cast-iron rings at the top and two at the bottom. Each of the bronze exhaust valves covers the whole top of its cylinder and has two pins working in a retaining cross-bar which itself fits into slots in the cylinder head, where it is held partly by the valve spring between it and the valve and additionally locked by the cover-retaining bolt, which.fits into a hole cut in the centre of the cross-bar.

The exhauster-pump drive is by skew gearing, which, is normally idle except when brought into play by means of a special form of clutch operated by the ball-ended control lever situated between the two cylinders.

The exhauster pump gives a water lift of 26 ft. in approximately 26 seconds. -The length of the suction hose is unimportant, providing that the lift does not exceed this figure. The main pump spindle carrying the impellers is supported at the inlet end in a white-metal-lined bush protected from the inlet water by a domed cover, whilst at the front end it is carried in two ball bearings.

• There is only one gland in the whole pump, and this is where the central spindle passes through the front cover. The gland, which is also covered by a patent, is provided with what is known by the makers as a catapult fork, which_ affords means of adjustment. The fork is pivoted at its open end on a pin, whilst two projections_ towards the centre press against grooves in the gland. At its other end is a screw and milled nut, ny which pressure on the gland can be adjusted. It will be noted that this gives a balanced pressure on the gland, and by withdrawing the pivot pin the catapult fork can be ,slipped out and the gland run back along the spindleto give easy access for epacking.

The controls consist of a wheel-operating valve between the twin exhauster pumps and the suction, and ordinary sluice valves for each delivery. The wheel valve carries three arrows ; when one of these points. to the suction and the other two to the exhauster cylinders, the turbine is in position for being primed by both exhauster cylinders, and to commence this operation the clutch-operating levcr is held forward. So soon as the pump is primed, i.e., picks up the water, the clutch-operating lever is released, thus cutting out the suction pumps, and the wheel valve is then given a half turn until the central arrow points upwards. This prevents water from getting to the air pumps. In case of emergency, such as the failure of one exhauster pump cylinder, this may he cut out and the other employed. In this ease the wheel valve is arranged with one arrow pointing to the suction and the central arrow pointing in the direction of that exhauster cylinder which it is desired to Two pressure gauges are .provided ; that on the tight, looking at the pump from the rear, being of the compound type, reading for vacuum on one side anci main pressure on the other. The gauge at the left shows the pump head pressure, which averages about 120 lb. per square inch, but can be raised to 150 lb. per square inch if required.

One of the great advantages of the new patent pump is that it can be fitted to existing vehicles with very few alterations, and in some cases none. In certain instances, tire tenders not previously fitted with pumps have been so equipped, with great success.

During cur visit to the 'Dennis factory we observed a No. 2 model pump being fitted to a Fiat tender for the Brighton 1ire Brigade ; this machine

previously carried hose, men and a big escape., but no pump. The pump is being fitted at the rear and is driven from the gearbox through an auxiliary gear anc:, cardan shaft. A Ford onetonner was also being equipped with the No. 1 model pump. It will be interesting to note that the addition of the pump, which; in the case of the Ford, is fitted at the front of the vehicle and geared up to the crankshaft, does not interfere with the starting, for a starting dog clutch is fitted at the front end of the impeller spindle, and the cover is so arranged that the ordinary starting handle can be inserted without any difficulty. The, pump is supported on the chassis frame by stout forged brackets, and its total weight is only 90 lb. .

Thus, any community can obtain a satisfactory fire-fighting appliance, for the cost of the vehicle (which is probably one already in commission) and the pump utilized, plus the cost of fitting. We have already given the prices of the pumps, and the cost of fitting is very little, being merely a question of the time .occupied on each job. It must not be thought because these two-stage turbine pumps are small that they are in any way delicate. As a matter of fad they are very strongly constructed, and the working parts have wearing surfaces of ample area.

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Organisations: Bradford Brigade

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