32S 



NATURE 



[August 2, 1894 



THE INSTITUTION OF NA VAL ARCHITECTS. 



THE annual summer meeting of the Institution of N'.ival 

 Architects was held last week, at Southampton, com- 

 mencing on Tuesday, July 24, and concluding on the Friday 

 following. 



The President of the Institution, Lord Brassey, occupied the 

 chair during the sittings, which were held in the theatre of the 

 Hartley Institute. There were only seven papers set down for 

 reading during the three sittings that were held for business 

 purposes, the meeting being, perhaps, rather more of a social 

 nature than usual. The following is a list of the papers : — 



(1) " On the Harbour and Docks of Southampton," by John 

 Dixon, Dock and Marine Superintendent of the London and 

 South Western Railway Company. 



(2) " On the Importance of Economy of Fuel in very Fast 

 Vessels, and on the advantages to be derived from Heating the 

 Feed-water," by J. A. Korroand, of Havre. 



(3) " On the Influence of Circulation on Evaporative 

 Efficiency of Water Tube Boilers," by J. I. Thornycroft. 



(4) " On the Design of Mail Steamers, with special refer- 

 ence to their use for War Purposes," by J. H. Biles. 



(5) "On a Rapid Method of Calculating Welted Surfaces," 

 by Archibald Denny. 



(6) " Recent Experience with Cylindrical Boilers and the 

 Ellis and Eaves Suction Draught," by F. Gross. 



(7) "The Ventilation of Steamships, with special reference 

 to the Removal of Explosive and Foul Gases from Bulk Oil 

 Steamers," by S. H. Terry and J. F. Flannery. 



Mr. Dixon's paper does not call for extended reference at 

 our hands ; it was intended chiefly as a guide to members who 

 were about to visit the Southampton Docks in the afternoon, 

 and was excellently designed for this purpose. Perhaps the 

 most generally interesting part of the paper was contained in 

 the appendices, in which a brief history was given of the various 

 steamship companies that used the docks at Southampton. In 

 a note attached to the paper, some interesting historical details 

 were given. Although Southampton is a very ancient town, its 

 importance was not great in the early days of this century. In 

 the year 181 1, we learn that the chief trade was with Jersey, 

 Guernsey, Alderney, and Sark. Several sloops were running 

 between these islands and Southampton. There was also a 

 carpet and a silk manufactory, as well as mills for manufacturing 

 blocks and pumps for ilie Navy. The number of houses in the 

 tiiwn then was 1582, and the population was under 8000. The 

 ship-building industry, however, goes back to very early days, 

 Mr. Dixon stating that in the reign of Henry V. the famous 

 ships Grace Dicu and Holy Ghost were built at Southampton ; 

 this was about the year 1414. One of the vessels was built by 

 Robert Berd, and the other by William Soper; and it is curious 

 to notice that one of the well-known yacht-designers of the 

 district is now a Mr. So|ier. Each of the ships referred to cost 

 about Z'500. During the last century, and in the early days of 

 this century, a very large number of ships for the Royal Navy 

 were built in this district. At a small place called Bucklers 

 Hard, now seldom heard of, a number of famous ships were 

 constructed. This is on the little river Exe, which flows through 

 the New Forest and past IJcaulieu Abbey to the Solent. Three 

 ships of the Britith Fleet which were at Trafalgar, were built 

 there, the most celebrated being Nelson's Agamemiioii and the 

 Swifliurc. Another interesting historical fact stated by Mr. 

 DixoD, was that the timbers of the celebrated American 

 frigate Chimfeaie were used, when that vessel was broken up, 

 in the consitruclion of a mill at Wickham, near by. The building 

 still exists, and is known as "Chesapeake Mill." The late 

 Admiral of the Fleet, Sir I'rovo W. Parry Wallis, who died 

 only a short lime ago, in 1813 took the Chnafeakc into Halifax, 

 after her encounter with the Shannon. 



M. Normand'.s paper was one of considerable value, and, 

 though short, contained a good deal of useful information. The 

 well-known scientific allainmenis of French naval architects 

 are excellently represented in M. Norman'i's firm, and from 

 the Havre yard have been turned out some of the torpedo boats 

 which have Iwcn most worthy to be placed in competition with 

 the productions of the Thames builders, Thornycroft and 

 Yarrow. M. Normand is an original designer, his conclusions 

 being based on scientific deduction. He is not content, as 

 some other constructors of fast vessels arc, to simply follow the 

 lead of others, ignorantly copying whatever they may see to be 

 successful. As is usually the case with scientific workers, M. 



NO. 1292, VOL. 50] 



Normand is generous in giving information to others, even to 

 his competitors ; although he would probably be the first to 

 acknowledge his indebtedness in this respect to the two leading 

 torpedo boat-builders of this country. Indeed, the interchange 

 of information in this way across the channel has always been 

 a pleasant feature in the rivalry of the builders of these beau- 

 tiful little craft. Torpedo boats are not supposed to be 

 economical vessels, and it has been said that " the mission of 

 a torpedo boat is to run a trial trip." There certainly wxs a 

 great deal of truth in this remark in the old days of premium 

 for speed, when a boat might earn for her builders several 

 thousand pounds over her contract price if she could scramble 

 through her six runs on the mile w ilhout breaking down. In 

 such a case, as there was no restriction in regard to coal burned, 

 economy of fuel was little thought about, and indeed in the 

 ultimate work for which torpedo boats are designed, should they 

 ever be brought to the stern realities of war, it would be a small 

 matter whether much or little coal were burned to attain the high 

 speed. To get to the scene of operation, however, a torpedo 

 boat might have to run a long distance, and in that c.tse her 

 radius of action in regard to coal stowage would be a serious 

 consideration. Moreover, trial trips of torpedo boats now extend 

 over a considerable length of time, and the amount of coal that 

 has to be carried h.is become an important factor in regard to 

 the total weight, which, of course, in turn governs the speed to 

 a large extent. M. Normand h.as recognised these facts ; he tells 

 us that in his last torpedo boats he has found, by the oflicial 

 trials, that the coal burned per I. H.P. per hour ranged from 

 II lb. up to 15 knots, and to somewhat less than 2 lb. at 25 

 knots. These figures seem very low, and the author is certainly 

 within the mark in saying that the consumption is not more than 

 two-thirds of that of a number of similar craft. Another 

 interesting and valuable piece of information, given us by M. 

 Normand, is that the total weight of engines and boilers of the 

 boats above alluded to, is about 48 lb. per maximum I. H.P. 

 and even this extremely light machinery is further reduced in 

 weight, notably in the case of the Forban, now under 

 construction at Havre ; a vessel, it will be remembered, which is 

 expected to reach a speed of 30 knots an hour, although we 

 believe the contract speed is 29 knots. It may be mentioned 

 here, that Mr. Yarrow has under construction, for the Russian 

 Government, a vessel which is guaranteed to make 30 knots. 

 M. Normand further tells us in his paper, that in high-speed 

 vessels a reduction in the weight of any part of the ship allows 

 the whole displacement to be reduced by about 4^ times 

 the weight saved, if the speed, steaming distance, weight of 

 armament, and general conditions remain unchanged. Phe 

 author attributes the remarkable economy of his engines to 

 several causes, but more particularly to the feed-healer that he 

 uses. This, he informs us, gives an economy in fuel of at least 

 20 per cent. The figures seem somewhat starlling, but they 

 are vouched for by the author, and have been obtained on 

 oflicial trials. The principle of this foedhealer was enunciated 

 for the first time in 18S6 by the author's brother, M. Benjamir* 

 Normand. It is a direct application of the first law of thermo- 

 dynamics. The heating steam is taken, in the ordinary compound 

 engine, at mid-stroke from the low-pressure cylinder by a special 

 valve. In three or four stage expansion engines it is taken 

 direct from the low-pressure casing, all the work previously 

 given in the engine by the heating steam being a direct gain. 

 The author ascribes the economy of 20 per cent., before 

 mentioned, to two causes, viz. : (l) That which results from the 

 number of thermal units saved by using, for healing the feed, 

 steam which has already done work. "This may amount to from 

 10 per cent, to 14 percent., according to the pressure. (2) That 

 which results from the better circulation of the water in the 

 boiler, a greater proportion of that water being at a boiling 

 temperature. As a practical example of the advantages of lhi» 

 healer, it may be staled that simply by putting it into use, the 

 revolutions of the engine in one vessel were increased from 305 

 'o 335 per minute. 



A short discussion followed the reading of this ]>aper, in 

 which both Mr. Thornycroft .n;id Sir Nathaniel Harnaliy took 

 p.Trt. The chief point of interest was the slalemcnt by Mr. 

 Thornycroft, that in the case of the Darhif;, a torpedo boat 

 destroyer recently built by his firm, he believed the weight of 

 machinery per MI. P. was even less than that slated by M. 

 Normand. 



Mr. Thornycroft's paper, like that which preceded it, con- 

 tained a good deal of valuable information in a small compass. 



