LARGE vs. SMALL STREAMS.
THE discussion in these columns of the relative merits of large and small streams of water in the extinguishment of fires has excited marked attention, not only in this country, but in Europe, the Firemen’s papers abroad, and several prominent European Firemen, taking part in it. These generally sustain Captain Shaw in the exclusive use of small streams. From the evidence adduced, it appears that the Departments of this country, as a rule, have the advantage of their European friends, inasmuch as they carry appliances by means of which they can use either small or large streams, as the emergency requires. What size stream to use is largely a matter of judgment, dependent upon the conditions under which each fire has to be combatted. We reproduce an editorial from the London Fireman which will be read with interest by all who desire to inform themselves on the subject.
An interesting discussion upon the relative value of large and small streams for fire extinguishing has recently been proceeding in the columns of the Fireman’s Journal of New York. The use of small streams is advocated by Mr. Charles Oyston, a veteran Fireman, well known in America, and Chief Martin Cronin, of Washington, comes forward as the champion of larger jets. We do not intend to give any resume of the arguments employed on either one side or the other, because they are mainly scientific, and we are strongly of opinion that the question will not be satisfactorily decided upon scientific grounds. Nothing is more certain than the fact that no two fires of any magnitude are exactly alike in all particulars, and it necessarily follows that no single method of applying water can be properly employed in extinguishing them. The position of the fire, the area covered by it. the amount and character of the goods,and the size of the premises endangered, the distance to which the fire can be approached , the quantity of water available for use, the pressure in the mains, and the capacity of the engines, will all vary at different fires, and each circumstance has to be taken into consideration in determining the size of the jet to be attached to the end of the branchpipe in dealing with them.
Mr. Oyston, in one of his papers, says :—“ I shall now take the stand that water extinguishes fire by absorbing the heat, and that the amount of heat a given quantity of water will absorb will depend very much upon the amount of fire surface it is made to cover. Now comes the question whether sixteen half-inch streams or one two-inch stream will cover the most surface,” and he then proceeds in effect to argue that sixteen smaller streams will cover more surface, and therefore arc better adapted for fire extinguishing, than the single two-inch stream. Now, we have very little to object to Mr. Oyston’s theory, nor to his manner of stating it, but we do not see that the question is of much practical importance to Firemen. We do not believe any experienced Fire Brigade officer would sanction the use of a two-inch stream if he could get near enough to the fire to use the smaller jets ; but if the fire were raging fiercely and a near approach could not be gained, the smaller streams might not reach the seat of the fire at all, and the relative value of the two sizes under such circumstances is not worth discussing. On the other hand, our experienced officer would not dream of sending a man up a ladder with a two-inch (supposing it were possible) or even a half-inch stream to fight a fire in a closet, or to extinguish a small fire in a cottage chimney. In determining the proper size of the stream to be employed, we repeat that all the conditions previously mentioned will probably have to be taken into account.
The case may, we think, be stated thus: For the purpose of extinguishing the fire only, the greatest possible amount of water which can be brought into contact with the seat of the fire, that is to say, with the substances actually burning, is the most effective. But for the purpose of extinguishing the fire with the least possible damage and loss, which all Firemen should aim at, the least quantity of water which will hold the fire in check and prevent its spreading must be employed. If the water does this perfectly it will soon gain ground and extinguish the fire.
Any water which does not strike the burning material directly is, in ninety-nine per cent of cases, useless or worse than useless. A quarterinch jet from a hand pump, held close to the seat of the fire, will do more service than a two-inch stream from a steamer thrown at random, no part of which, it is most likely, comes into contact with the actual fire.
In deciding what jets to use at a fire, a little practical experience is worth any amount of science, and upon the former reliance must always be placed by Fire Brigade officers. A superintendent has, we will say, a six-inch London Brigade pattern manual engine, and a good supply of water, so that it can be worked up to its full power without fear of running short. With this engine he can either use one 3/4-inch, two 9-16-inch, or three 15-32-inch nozzles. But where does science come in to teach him which he should decide upon at any particular fire? He has really to consider mainly where the fire is, whether it is spreading in more than one direction, how close he can get to it at one or more points, whether the property is certain to be a total loss. If it covers a large area, and can be attacked with advantage from several sides, he will use his three jets. If it is raging intensely at one spot, but gaining ground slowly in other directions, he will concentrate all his power upon a single stream, for the reason chiefly that to throw two streams upon a single spot is to work against twice the inevitable amount of friction in the hose, and to put therefore the same quantity of water upon the fire as through a single nozzle with less force. If the fire is in a single room, and has made little progress, he will order the engine to stand by, and send down a man with a handpump (should he be wise enough to have one with him), having a X-inch or 5-i6-inch jet, and put out the fire with that. His line if action must be determined upon when he has arrived at and surveyed the fire ; we are confident no scientific men in America or elsewhere can tell him what to do before he leaves the station.
In suppotl of the opinions we have expressed, we may quote a paragraph from a letter contributed to a contemporary by Mr. Superintendent Tozer, of the Manchester Fire Brigade. He says—“It appears tome that if we extract from these two most elaborately written articles the scientific information imparted, and take the common-sense view of the points raised, that both gentlemen have clearly demonstrated the fact that different sizes of jets are required at fires, and that those Firemen will best succeed in giving satisfaction to those directly interested in the property at risk who endeavor to subdue the fire with the least possible quantity of water. Experience teaches that medium size streams, say are generally found sufficient at ordinary fires, but in cases where the water has to be projected into lofty buildings, or to considerable distances, then one inch, or at the most 1 1/4-inch, streams are found more effective.
In real work the Firemen depend (because they are generally successful) in rapid movements with light appliances, advancing and attacking the enemy at close quarters ; this could not be done up ladders and staircases with two such streams. Standing in the streets and projecting large volumes of water to considerable heights, or with great force, may please the onlookers, but this is not subduing fire with the least possible loss or damage by water. Mr. Cronin says, if a sufficient quantity of water can be readily injected into the base or centre of the fire it can be readily extinguished ; that is nearer the mark ; then why advocate two such streams?
Most Firemen will agree with the opinion Captain Shaw is said to have expressed, viz., that 2-inch streams are not required, and I will add that it is absolutely necessary in the limited space in our fire machines to carry onlv those implements which are found by experience to be generally the most useful, and Firemen on this side of the water will, I think, be of opinion that handpumps with 5-16 jets are more useful than ever 2-inch streams can possibly be.”
The “drowning-out” process at fires may be necessary in more instances in American experience than in that of English Firemen ; but we believe it is very frequently adopted in the States when occasion does not really require it. The testimony of American writers would seem to show this ; one of them, in a letter we printed last month, calls for ” more judgment and less water” at fires, and hints that It is the practice with some Fire Brigades to drag the hose (charged with water, we presume) though the burning houses whilst looking for the tire. This is not how English Firemen go to work, and we are bound to say it is extremely likely that one of the reasons why the fire loss, spile of the undoubted superiority of American Fire Departments in many respects, is much less in England than in the States, may be found in the greater discretion manifested by our Fire Chiefs in the use of water. At ail events, the argument is a fair one, and if some of our many American friends have anything to say per contra we shall be glad to hear what it is.