Fire prevention and fire extinction

by James Braidwood

Some objections have been made to riveted hose on account of the alleged difficulty of repairing them; but this is not so serious a matter as may at first view appear. Indeed, they very seldom require any repairs, and when they do, the process is not difficult. If any of the rivets be damaged, as many must be taken out as will make room for the free admission of the hand. A small flat mandrel being introduced into the hose, the new rivets are put into the leather, and riveted up the same as new pipe; the mandrel is then shaken out at the end.

If the leather be damaged, it may be repaired either by cutting out the piece, and making a new joint, or by riveting a piece of leather upon the hole.

The manner of attaching the hose to the coupling-joint is also a matter of very considerable importance. If a joint come off when the engine is in operation, a whole length of hose is rendered useless for the time, and a considerable delay incurred in getting it detached, and another substituted.

To prevent this, the hose ought to fit as tightly as possible to the coupling-joint, without any packing. In riveted hose, a piece of leather, thinned down to the proper size, should be put on to make up the void which the thick edge of the leather next the rivet necessarily leaves; the hose should then be tied to the coupling-joint as firmly as possible with the best annealed copper wire, No. 16 gauge.

When the hose are completely finished in this manner they are proved by a proving-pump, and if they stand a pressure of two hundred feet of water they are considered fit for service. I may also add, that when any piece of hose has been under repair it is proved in the same manner before it is deemed trustworthy.

The proving of the hose is of very considerable importance, and the method of doing so which I have mentioned is greatly superior to the old plan of proving them on an engine or fire-cock. By the latter method, no certain measure can be obtained by which the pressure can be calculated. In the first place it must depend on the relative height of the reservoir from whence the water is obtained and that of the fire-cock where the experiment is made; and as the supply of water drawn from the pipes by the inhabitants may be different on different days of the week and even in different hours of the day, it is quite evident that by this method no certain rule can be formed for the purpose required, the pressure being affected by the quantity of water drawn at the time.

The method of proving by an engine is considerably better than this; but when a proving-pump can be obtained it is infinitely better than either. One disadvantage of an engine is, that it requires a considerable number of men; but even the proof, that of throwing the water to a given height on the gable of a house or other height, is not always a test of the sufficiency of the hose. As the temperature is low or high, the wind fresh or light, the degree of pressure on the hose in throwing the water to the required height will be greater or less. Indeed, in high winds it is a matter of extreme difficulty to throw the water to any considerable height.

With an engine of 7-inch barrels and 7-inch stroke, fitted with eighty feet of 2-3/8-inch hose, I have found from several experiments that when the water is thrown seventy-five feet high, the pressure on the hose is equal to one hundred feet. The same engine, with 160 feet of hose, and the branch-pipe raised fifty feet above the level of the engine, when the water was thrown fifty-six feet from the branch, occasioned a pressure equal to 130 feet on the hose. From these experiments, I am convinced that the pressure will not be equal to 200 feet, except in very extreme cases, or when some obstacle gets into the jet pipe.

I tried the extreme strength of a piece of riveted hose 4 feet long and 2-3/8 inches diameter, and found that it did not burst till the pressure increased to 500 feet; and when it gave way the leather was fairly torn along the rivet-holes.

Every possible care should be taken to keep the hose soft and pliable, and to prevent its being affected by mildew. After being used, in order to dry them equally they should be hung up by the centre, with the two ends hanging down, until half dry. They should then be taken down and rubbed over with a composition of bees'-wax, tallow, and neats-foot oil,[N] and again hung up to allow the grease to sink into the leather. When the hose appear to be dry they should be a second time rubbed with the composition, and then coiled up for use. In order that the hose undergoing the operation of greasing may not be disturbed or used till in a fit state, it is better to have a double set, and in this way, while one set is in grease the other is in the engine ready and fit for service. More time can also be taken for any repairs which may be necessary, and they will in consequence be more carefully done, and at fires where a great length of hose is required the spare set will always be available. When the weather is damp, and the hose cannot be dried so as to be fit for greasing in two or three days, a stove should be put into the room in order to facilitate the process. The greatest care, however, must be taken in the use of artificial heat. The whole apartment should be kept of one equal temperature, which ought never to be higher than is requisite to dry the hose for greasing in about forty hours.