Fire Prevention and Fire Extinction Part 13

3rd. The third standc.o.c.k was opened, and the jet from the first 40 feet high.

4th. The fourth standc.o.c.k being opened, the first gave a jet of 35 feet high.

5th. The fifth being opened, the first gave a jet of 30 feet high.

6th. All the six being opened, the first gave a jet of 27 feet in height.

_2nd Experiment._--Six standc.o.c.ks were then put into plugs, on a main 9 inches diameter in Tooley-Street, the extreme distance being 450 yards, with hose and jets as in the first experiment. The water was brought from the head at Battersea by 4250 yards of iron pipes of 20 inches diameter, 1000 yards of 15 inches diameter, 1400 yards of 9 inches diameter. The weather was nearly the same, but the place of experiment was more protected from the wind than in Union-street.

1st. With one standc.o.c.k open, a jet 60 feet in height was produced, and 107 gallons per minute were delivered.

2nd. The second standc.o.c.k was then opened, and the difference in the first jet was barely perceptible.

3rd. Other two standc.o.c.ks being opened, the first jet was reduced to 45 feet in height, and the delivery to 92 gallons per minute.

4th. All the six standc.o.c.ks being opened, the first jet was further reduced to 40 feet high, and the delivery to 76 gallons per minute.

_3rd Experiment._--Two standc.o.c.ks, with hose, &c., as in the first experiment, were then put into a service-pipe, 4 inches diameter and 200 yards long, in Tooley-street, the service-pipe was connected with 200 yards of main 5 inches diameter, branching from the main of 9 inches diameter. The weather was still the same as at first, but the wind did not appear to affect the jets, owing to the buildings all round being so much higher than the jet.

1st. The standc.o.c.k nearest the larger main was opened, and a jet of 40 feet high was produced, delivering 82 gallons per minute.

2nd. Both standc.o.c.ks being opened, the first gave a jet of 31 feet, and delivered 68 gallons per minute.

3rd. The standc.o.c.k farthest from the large main only being opened, gave a jet of 34 feet, and delivered 74 gallons per minute.

4th. Both standc.o.c.ks being opened, the farthest one gave a jet of 23 feet, and delivered 58 gallons per minute.

When both these plugs were allowed to flow freely without hose, the water from that nearest the large main, rose about 18 inches, and the farther one about 1 inch above the plug-box.

[Ill.u.s.tration: FIG. 7. Common Fire-plug.]

These and other experiments prove the necessity of placing the plugs on the mains, and not on the service pipes, where there are mains in the street.

The different modes of obtaining water from the mains or pipes are shown in the accompanying drawings.

(Fig. 7) is a section of a common plug when not in use.

[Ill.u.s.tration: FIG. 8. Fire-plug with canvas cistern.]

(Fig. 8) is a section of the common plug, with a canvas dam or cistern over it, as used in London. The cistern is made of No. 1 canvas, 15 inches deep, extended at top and bottom by 5/8-inch round iron frames, a double stay is hinged on the top frame at each end. When the cistern is used the top frame is lifted up, and the stays put into the notches, in two pieces of hoop iron, fixed to the bottom frame. There is a circular opening 9 inches diameter in the canvas bottom, two circular rings of wash-leather, about 2 inches broad, are attached to the edges of the opening in the canvas, so as to contract it to 4 inches or 5 inches diameter; the plug being opened, the cistern is placed over it; the wash-leather is pressed down to the surface of the road by the water, and a tolerably water-tight cistern, with about 12 inches or 14 inches of water in it, is immediately obtained.

[Ill.u.s.tration: FIG. 9. Plug, with Standc.o.c.k.]

(Fig. 9) is a plug with a standc.o.c.k in it, to which hose may be attached.

(Fig. 10) is a common single firec.o.c.k with a round water-way 2-1/2 inches diameter.

[Ill.u.s.tration: FIG. 10. Single Firec.o.c.k.]

(Fig. 11) is a double firec.o.c.k, as laid down in Her Majesty's Dockyards.

[Ill.u.s.tration: FIG. 11. Double Firec.o.c.k, used at the Royal Dockyards.]

It will be observed, that the short piece of pipe between the main and this firec.o.c.k is not curved to the current of the water, but merely opened a little; this is done with a view of increasing the supply by steam power, and as the steam engines are, in most cases, situated in a different direction from the tanks or reservoirs, therefore the curve that would have a.s.sisted the current in one direction would have r.e.t.a.r.ded it in the other. It has been objected to these firec.o.c.ks, that the opening does not run through the centre of the key, therefore only one side of the key covers the opening in the barrel, while in the common firec.o.c.k both sides are covered.

[Ill.u.s.tration: FIG. 12. Double Firec.o.c.k, used at the British Museum.]

(Fig. 12) is a double firec.o.c.k, as laid down at the British Museum.

This has a very good delivery, and is certain to be always tight, if well made, as the pressure of the water forces the key into the barrel; this also renders the c.o.c.k somewhat difficult to be opened and shut, if the pressure be great; but as a lever of any length may be used, and the key, from its perpendicular position, may be loosened by a blow, this objection is in a great measure obviated.

In Figs. 10 and 11 the openings in the street are large enough to admit of the levers for opening the c.o.c.k to be fixed, that no mistake may occur from the lever being mislaid; but with those at the British Museum, it was not thought necessary to have fixed levers, as a crow-bar, or anything that could be introduced into the eye of the spanner, would open them.

The plug and firec.o.c.k have both certain advantages and disadvantages, which are now described.

The plug, with a canvas cistern, is the easiest mode of obtaining water; the plug-box being only the size of a paving-stone, is no annoyance in the street, and the water has only one angle to turn before it is delivered.

On the other hand, where the supply of water is limited, the plugs give but little command of it; there is, however, comparatively very small loss at a large fire in London from this cause, as it is very seldom that all the fire-engines can be supplied direct from the plugs, and those that arrive late must pick up the waste water as they best can, by using another description of canvas dam, or opening the street; but in enclosed premises, especially where the water is kept for the purpose of extinguishing fires, firec.o.c.ks are much to be preferred. It is very difficult to insert the standc.o.c.k into a plug if there is a considerable force of water, and if the paving has moved, it cannot be done without raising the plug-box; but this is, however, the easiest mode of using firec.o.c.ks, and where there is a considerable pressure of water, if the watchmen or the police are supplied with a hose-reel and branch-pipe, they can, in enclosed premises, direct a jet on the fire while the engines are being prepared, and if they cannot reach the fire, they will have water ready for the engine when it arrives.

Inclosed premises are particularly mentioned, because the princ.i.p.al duty of the watchmen, in these cases, is to guard against fire, and their other duties being comparatively few, the men are not often changed, and they can be instructed thoroughly in the matter. With the general police of the metropolis it is quite different, their duties are so numerous and varied, that to add that of firemen to them would only be to confuse them.

Firec.o.c.ks, if kept at 9 inches to 12 inches below the surface, are easily protected from frost, by stuffing the opening with straw.

The advantage which the double firec.o.c.ks have over the single ones, is merely the increased water-way, as a firec.o.c.k 3-1/2 inches diameter could not be so easily opened or shut, as two c.o.c.ks of 2-1/2 inches diameter.

One of the greatest objections to firec.o.c.ks, is the very large openings required in the streets, the first cost and the repair of which are both considerable, besides their liability to accident. To take them to the footpath, increases the expenses and diminishes the supply of water, as it is generally done with a small pipe, and the number of angles is increased. In some instances, where firec.o.c.ks have been put down on one side of the street, no less than four right angles have been made in the course of the water; and if the fire happens to be on the opposite side of the street from the firec.o.c.k, the thoroughfare must be stopped. The expense also is no slight consideration, for if laid along with the water-pipes, each firec.o.c.k, if properly laid, and the pit built round with cement, will cost eight or ten times as much as a plug.

London is, upon the whole (except in the warehouse districts), fairly supplied with water for the average description of fires, that is, where not more than five or six engines are required. When, however, it is necessary to work ten or twelve engines, there is very often a deficiency. In many of the warehouse districts the supply is very limited indeed, although it is there that the largest fires take place.

The water companies are generally willing to give any quant.i.ty of water, but they object to lay down large mains without any prospect of remuneration. The warehouse keepers decline to be at the expense of laying the pipes, and there the matter seems to rest. In most other places of importance, the water is under the management of the civic authorities, and they, of course, endeavour to obtain a good supply of water at fires in warehouse as well as in other districts.

In supplying fire-engines with water from firec.o.c.ks, one or more lengths of hose are screwed on the firec.o.c.k; the extreme end being put into the engine, the firec.o.c.k is then opened and the water rushes in.

When the water-pipes are large and the pressure considerable, two or even three engines may be supplied from the same firec.o.c.k.

If the firec.o.c.ks are all at too great a distance from the place on fire, to be reached by the supply of hose brought with the engine, the next resource is, to open the nearest firec.o.c.k above the level of the place where the water is required. By covering the eyes of drains, and stopping up any cross-water channels, the water may in this manner be conveyed along the street, from a very considerable distance. From the nature of the ground it does not always happen that the water will run directly from the nearest firec.o.c.k, to the spot where it is required; acclivities, buildings, and many other causes, may prevent this; but in some of these cases a few lengths of the hose, attached to the firec.o.c.k, may convey the water to a channel which will conduct it to the required point. Upon the arrival of the water, it ought to be dammed up, and the engine will lift it by suction out of the pool so formed.

If, however, from the nature of the ground, from the want of hose, or from other causes, it is found impracticable to convey the water by either of the above methods, the next best is, to conduct the water in hose as far as can be accomplished, and carry it the remainder of the distance in carts, buckets, or whatever else may be most convenient.

When carried in buckets it is of advantage to form a line of men from the water to the engine, each man covering five or six feet of ground.

The buckets are then handed from one man to another, till they reach the two or three men who are stationed round the suction-tub or fire-engine to receive them. The buckets when emptied are returned by a different line of men (women or boys) stationed in the same manner as the former. If a sufficient number of hands cannot be had to return the buckets in this manner, any convenient number may be employed to carry them to the firec.o.c.k, that they may be again filled. When a fire occurs where the water-pipes are unprovided with firec.o.c.ks or plugs, the ground should be immediately opened, and the water-pipe cut. If it be of cast-iron, a large hammer may effect the purpose: on the water-pipe being broken, the suction-pipe of the engine is placed in the opening so made. If the pipe be of lead, the opening in the street should be made of sufficient length to admit of one end of it, when cut, being turned into the engine. If the supply of water by this means be so great as to occasion waste, it may be regulated by the nearest stopc.o.c.k on the water-pipe, by driving a wooden plug into the end of a cast-iron pipe, or compressing the end of a leaden one.

The next plan I shall notice of supplying fire-engines is from drains, gutters, &c. In particular situations and wet weather considerable supplies of water from these and similar sources may be obtained. In the gutters all that is required is to dam them up; and, if there be no materials at hand for this purpose, the causeway must be dug up, till there is a sufficient depth of water for the suction-pipe of the engine.

When the water is to be drawn from drains or common sewers, great care should be taken not to damage them farther than is absolutely necessary.

If enough of cover be taken off to allow one man to enter easily, it will be quite sufficient for all necessary purposes. When the man inside the drain or common sewer has collected a proper supply of water by damming up the channel, the suction-pipe should be handed down to him, and the engine set to work.

Although it be true that foul water quenches fire, I will here observe, that the water from a common sewer should never be used, except when it is impossible to procure it from a purer source. For the purpose of procuring water to extinguish a fire, I had at one time occasion to open a common sewer, in which, with the usual impurities, the waste from a gas manufactory was intermixed, and the stench in the premises where the fire had been extinguished by this water, was for some time after very disagreeable.