Star. — London, England, 1817-07-17 00:00:00

REPO REPO RTfroin du SELECT CUMMR2 EE on STEAM BChiTS. MINU FES OF EVIDENCE. CRARIAIS HAMMY, EA. the Chair. Mr. Buse Aoki, called in And examined. Were you desired to go down to Norwich, to in quire into the cause of the explosion of the Steam- B o at ?—.l went down as a volunteer. Did you see the Steam-beat?—No, we did not; it had been removed; we saw he boiler and pars of the engine. . • Of wh..m do you speak ?-e r Mr..Tisnothy Bramah and Mr. Collinge accompanied me. They were persons peefectly-konversant with en gines ?—Yes. You saw the boiler and the engine ?.--T did. In your opinion, what was the cause of that explo sion ?—The immediate cause had been the use of steam of a very high expansive forte; the proximate cause was the deficiency in the strengh of the end of the boiler. Of what was that boiler made, and what was its construction ? It was made chidly of wrought iron, but partly of cast iron. What pan was wrought, and what part was cast The boiler was cylindrical; the cylindrical part and one end were wrought iron, and the other end was cnst iron ; it appeared to me to have been previously tif wrought iro is, but, for what reason I do nut know, the wrought iron cod had been cut out, and a cast iron end substituted in its place. . Is it vur opinion, that any beiler so constructed was unsafe ? As a high pressure boiler certainly. What do you calf a high pressure ? I sht•uld call from Whs. nem anis high pressure; the technical phrase is applied to engines u here the motive force is even by the expansive force of the steam. Deilee what is the techeical distinction between Vgli pressure and low pressure engines ? When water is made eoil in the boiler, and confined so, that the ste sm is not allowed to make its escape, it continues to acquire expansive force as it receives increase of hear; in the high pressure engine, the piston of the mean: cylinder is forced down by the expansive force of _the steam alone, against the re sistance of the atmosphere; when the piston has arrived at the bettor" of the cylinder, a valve is opened, and the steans i ie altiowed . to escape into the atmosphere, and the opt anon ii reversed; the piston of the cylinder is made Co ascend by the same kind of force. In the condensing engine, or the low pressure engines, the steam having been once permitted to fill the cylinder, a communication is then made between the cylinder in which the piston works and the vessel in which the steam is condensed : that is the distin guishing feature of the two engines. I will describe a further difietence, which contingently arises out of the vase of the two I that is, in the WO pressure engines the engineer has it at his option to use what degree cf ex pensive force he pleases, to convert an engine adapted for the power of five horses, or producing the power of live horses, to that of ten horses, or to any other ex• tent which he May think his materials capable of sus taining. In the luw pressure or condensing engines, Be steam can never be advantageously employed ove from Vi to Gibs. up-n a squat e inch. Whatever power there is in what y ciu call a hig pres sore engine, the ptessere in that engine may increase the power beyond what it is calculated for, and by means of that may render it dangerous I—Certainly. Is it your opinion, that a boiler could be made ut proper materials, whit satety valves, and under proper guard and direction, to make that high pressure pet teeny sale?--That would depend upon the quantity of pressure to be used ; a safety valve might be carried to 300, or to any assignable (Mee. I think that a high ' pressure engine may be made sale to a certain extent, bet where they are left ad libitum they never can be perfectly safe. Do you mean to convey the idea, that it is impose'. ble or difficult to adapt to a high pressure engine one or two safety valves joined with a mercurial gauge, acting at the same point of pressure, so as to make it equally safe with that upoti 'any other construction In answer to the first part .01 the question, relative to the safety valve, I think I have answered that already; that we can apply a safety valve to any degree of pressure without any diffieelty, but that the safety of the engine does not totally depend on the safety valve. State upon what other circumstancesehe safety of the engine depends ?—My idea of the difficulty of obtaining a proper degree of strength at all times hi the materials of which boilers may be made, arises from the constant deterioration which those boilers must be suffering from the action of the fire, and from the various degrees of expansion and contrac tion operating on difierent parts of the boiler. Is it then your opinion, that in high pressure en pines carried to that extent you mention, danger would always operate ?—lt Would nut alwaysoperate, but it would be extremely liable to accidents. 'ln fact you ,ourself would not chose to use a high pressure engine, from the difficulty which exists, either more or less ?—That is my opinion. Have you made any calculation what would be the force required to be used to propel a boat in na vigable rivers or canals ?—This does not admit of a definitive answer. It depends entirely upon opinion, how far one force would be dangerous and another not; but if Steam Engines arc employed for the purpok of propelling boats, that may be effected with perfect safety by the low pressure ar condensing en gines, where the pressure raced not exceed Sibs.- to the inch. Of course that must depend upon the resistance to be made, and the velocity required for the boat?— Then I must wake choke of a more or less powerful engine ;- I think it just to Jute to the Comniittee, that there is an advantage to be derived front the use of high pressure engines un board boats, which are necessarily loaded differently at different times; this different looting requires a different power in the steam Engine, and' A t e high pressure engine is ca pable of having this addisioral power given to it with out any difficulty, whereas ia the low pressure engine: t h e y ate confined to the force first assignectto diem.. 'What is the morainal of the low pressure engines scarcely ever saw them beyond 6 lbs. In high pressure engines there is a great saving of fuel ?--Thete is in one a peculiar kind of those carted high pressure engines; there is a considerable saving of fuel in Wooll's engines ; but in the common ones, I believe there is but little saving. It therefore the engines were to be used where as. saying of fuel would be of coolduable cookequcw;cl high pressnre,erigines of a cemin construction would be better adapted for that purpose thin low pressure engines?—Where the saving wa sof much consequence. If engines were to be used at sea, it would be of considerable consequence. the engine and the fuel being contained in a smaller compass ?—Woolt's en gine is not in a much smaller compass. When you talk of the deterioration of the boiler. bow long would a boiler properly constructed and constantly used. be used with safety'—That is ex tremely uncertain ; I have known one boiler worn out in six months, and another used for seven or 14 years. The strength of cast iron boilers is extremely uncer tain s cast iron contracts in various degrees in diffe rent places, and therefore is liable to break. You think that all cast iron boilers are dangerous?— Certainly, when used for steam of high expansive force. In your former answer, wh.:re you spoke of the ex treme difficulty of so regulating high pressure en gines as to ensure their satety, did you mean to speak of those which had cast iron boilers. or of both cast and wrought metal ones —Chiefly us to the cast iron. It is more practicable to make a boiler of the mune able metals to resist a high pressure, as far as the te nacity of the metals is concerned ; but another diffi culty occurs which prevents the application of the malleable metals to boilers for high pressure engines, which is that of rendering the jiiiiiing of the plates secure. Do you mean then to say that wrought iron boilers are not in frequent use to high pressure engines, in point of fact ?-•I believe they are in much less fre quent use than the cast iron boilers, and in Wuoll's engine they are scarcely used at all. In not the cast iron boiler much cheaper than the wrought ?.-I can scarcely tell that ; I should think the cast iron would be cheaper, if made of equal strength. In case of the explosion of a cast or a wrought iron boiler, which is attended with the greatest danger ? Cast iron, unquestionably. Why?—From the frangible nature of the metal. What do you apprehend to be the common effect, in case of the explosion of a cast iron boiler ?-•The metal is broken into fragments, and driven off with great violence in various directions. What is the effect when a wrought iron boiler gives way ?—Generally a rent ; but I have seen one instance of a wrought iron boiler, where the whole of the upper part was rent from the bottom, driven through the house in which it was placed, and carried to a considerable distance; I believe several yards. Do you apprehend, that speaking generally, and unless by some extraordinary circumstance, such as the wilful shuttirg of the steam valve, there would be any reason to apprehend such an effect as foil have just now mentioned, to arise from the renting of a wrought iron boiler?—No, I scarcely think it possible. Supposing the boiler to be made of wrought iron, or copper riveted, and safety valves properly ad justed, with a mercurial gauge also adapted in its diameter with due regard to the size of the boiler, do you conceive that any reasonable apprehension could anise resrecting the safety of a high pressure engine ?—I think there might ; but with less appre hension as to the exteut of the destructive effect to be produced. You speak of less apprehension as to the destruc tive effect; have the goodness to explain that ?-011 account that in the malleable metals a simple rend ing generally takes place, it would seldom happen that the upper part of the boiler would be torn tit . ; but in the cast iron the fragments would be scattered about, and be more destiuctive. Do you not know, that wrought iron boiler have been used to all sorts of steam rosins for a conside- rable time past ?—Yes. Did you ever hear of any other than the single in stance that you hare mentioned, in which a wrought iron boiler burst in such a manner?—No. Do you know what was the occasion of the top be ing blown off in the instance you nlentioned ?—We cannot tell what was the immediate :mon, but I suspected it to ariaa front the shape of the boiler. What was that shape ?—The bottom was of the usual waggon shape boiler, convex inwards • the concave part of she boiler was over the fire, an d those Who examined it with myself imagined that the en- 1 gine keeper bad suffered the water to be expended, or the whole of it nearly evaporated, leaving a small portion of it in the lag of the boiler. The boilers invented by Mr. Simms and Mr:Woolf were all of them cast iron ?—I believe they were; I never knew them make any other. Mr. Woolf's boiler has been it: use neatly ten years? I believe it has. Did you ever hear of any accident happening to their boiler ?—Yes, I have ; I heard it stated the other day, by a brother-in-law of mine, Mr. Hall of Dartford, that he had known two or three accidents, bfil Without any fatal or injurious effects. How many engines of the high pressure character have been blown up ?—I. have heard of several. Are there more than four ?—A great nary more, if there are taken into the account those which have exploded in America as well as here. Do you emisider, low pressure boilers as safe from explosion in all instances?—Used with no further pressure than six pounds. What renders them safe ?—Because they never em ploy steam of high expansive force in them. What arc the means by which they are prevented from using steam of high expansive twee in them ? Because jt would be against the interest of the persons using them to employ it. Is there any other guard against the condensing engine receiving such a charge of expansive steam as will burst it, than the care of the engineet or the in• retest of the owner ?—Certainly none ; because I have ki.own instances where they have used in the same engine both steam of a high expansive force, and condensed it at the same time. You havapever heard of low pressure boilers blow . ing up ?—Nos I have never known of any explosion with injurious conseqeettees ; they give way repeat edly; but do no injury: Is there any thing in low pressure boilers which may depended uposi absolutely, for preventing the steam acquiring an expansive force beyond what is intend ed regulated safety valves; mercurial gauges or water gauges will at all times secure it. Du those means of limiting the expansive force in low pressure boiler} continue perfectly effie scious un der all autism:Luce* of misconstruction and ma nagemmt?-entat entirely depends upon the strnctinn ; T have known safety valves fail in tliv. 4 4 action from bad construction. Can such or similar means be applied to high pres sure boilers '.Yes, certainly. is not the feeding of low pressure boilers nsualy done b 7 a column of seater; and is not this column the great reason of their safety'?—That is one reason, but they ought to have a safety valve besides. Is it not the principal reason of their safety '—lt is the most secure one. If the feeding column of water be taken away, is not the security left to depend upon the safety valve? Unquestionably. Are low pressure boilers employed in boats always, or commonly fed by a column of water ?—I never saw an instance of it. If the mechanical means which are used to render the low pressure boilers secure succeed, will not simi lar means render high pressure boilers secure ?—As far as the expansive force is not permitted to arrive beyond certain limits, so far it will afford security. At what tspanaive force are low pressure boilers safe, according to their usual construction ?—I have seen very few boilers constructed for the purpose of a low pressure engine, or a condensing engine that wonld sustain a pressure of ten pounds, without oc casioning considerable leakage, or without forcing the joints. Are they not very often used with a force to render them unsafe ?—l, never knew an instance of it. Is not the explosion of them likely to do sniv chic( ?—Not under the pressure they are capable of sustaining. Not even if they are made of cast iron ?—Catainly. Are they uniformly made of wrout,l►t iron ?-1;u ; several of them are made of cast iron. Are not the greater number of them made of cast iron ?—No ; 1 :I pprebend not. You cannot died state to the Committee bow many instances of explosion you know of high pressure boilers ?—No, I cannot. _ _ Are they more than in low pressure boilers ?—I never heard of an explosion in the low pressure boiler nt any consequence whatever, merely a givo.g way of the plates or the wearing out of the bcolets ; not such a bursting as can be called an explosion. May not every instance of explosion of the high pressure boilers with which you are acquainted, be traced to bad construction, or palpable mismanage ment ?—1 have never examined many of them, and therefore what they may be immediately traced to I do not know-; but all the explosions I have heard of have been occasioned by the use of steam of high ex. pansive force ; the one I visited at Norwich certainly arose from the detective construction of the boiler; it was extremely ill constructed. Was it not as well from the palpable mismanage ment of the engineer ?—That I do not know ; we were told tb3t it was ; I have no doubt there had been very great temerity and rashness. Was not that high pressure boiler which blew up in I.ondon the other day at a sugar -house, entirely owing to the most palpable misconstruction ?—I saw the boiler alter it had burst t and I certainly should not have made a boiler in drat shape, to have with stood the pressure which it was intended to bear. Was not that boiler made of a different thickness ; one of it three-quarters of an inch thick, and the oth er side two inches thick ?—Those are very nearly the dimensions t but in addition to that, there was a defect in the casting, what we csll a cold shut in the iron. Is not the use of high pressure steam completely :n its infancy ?—Ctrtaiiily, its introduction to general use is, of much later date than the low pressure steam engines. It is in tact to be considered as an invention of re cent date?—lt is. Have Dot material improvements taken place in the construction and ustt of high pressure boilers, in consequence of the accidents which have happened —I conceive Woolf's mode of constructing boilers to be a considerable improvement; a very material one I have likewi►e been told, though I have never seen one, that Trevethick has invented; a method of making boilers by increasing their length and de creasing their diameter, so as to render them capa ble of sustaining pressure to a much greater degree than heretofore. Tare more accidents occurred since the invention of the high pressure boilers, than might have been expected from the invention of any new system whatever in the mechanical coastruction of engines ? Perhaps not. What expansive force of steam is generally em ployed in those high pressure engines ?—I fancy that is very variable, from SO pounds to 120 upon the square inch, or even perhaps higher than that. Instances have been known in which a boiler has been worked at 160 and ISO • have there not ?—I have heard of such things, but I never knew of t arm. What is the proof to which high pressure boilers are generally exposed previous to their being used ? —The most eligible proof they ought to be exposed to, is by water. To what pressure ?—I should think double Ilse pressure to which they are intended afterwards to be subjected. What is the estimated Wee in your opinion which would burst a high pressure boikr of the best con struction ?—That is very different, because it deprfids upon the strength and construction of the materials; I never entered into the calculation. Have cot the greatest advantages been derived to the mines and manufactures from the use of the high pressure boilers ?—I believe inestimable advantages. Have you any doubt that Cornwall has de:ived an advantage which may be considered as incalculable from them ?—None in the world. Do yon think, from the few accidents which have occurred in the use of them, there is any better ar„u-. meet to be brought against the permitting them to. be employed, than could be derived from the acci dents which hare arisen in the explosion of gun. powder in the clearing passages in the mines ?—No,, not as applied to the mines, certainly. You have mentioned that security is afforded to the engine by feeding the boiler by a column of water; from what does that security arise ?—The pressure from the steam in the boiler could never rise to a force greater than that which would be equal to the pressure of thec.luma of water; when ever it did arrive at th a t pressure, or beyond that pressure, the water would be blown out and the steam mould follow. YO{. have smel t that in the Kelm vestels used 'open rivers, Wit ptee aution is not resot ts,l: taw one, and it would be extremely ient. For what reason ?-0.1 aced, .it the water would be subject t 44 ; ii we 4ld out of the pipe from the mra , ou et the other inconveniences would arise, sesch as b: r the pipe through the deck ut the vessel. Do you apprehend, that a me - sari sl 2:t4ive be exposed to the same inconvenrencvs I dry; the altitude would be lesse.ied by evt, assumed position of the vessel; that is, of a placed vertically at first, should by t' e Avian vetsell assume a diagonal or an altitude of the column would he consequent pressure ppm the steam Ipi t ei t ed. Are you of opinion that there would ie difficulty in Fu rding against such an inet‘ , .relsi as that I—Yes, I think there wool.!, rplly T. ing i hut a well constructed sakity vilve swtr all the purl) , :es. Are not the s.efety valves apo-,1 to the pi, 4 sure engines, even when the coliin:a of watts is to supply the boiler ?—Most tricoeutly they rue; 1 bave seen some without. Did you never hear ot 11e pressor- in a cerdeos. ing engine being raised by m.artheive,:;..t t as ti d y as 19 or 20 lbs. per inch ?—ti.); l J • n.l rect.liect that I ever met with SUCII a circuses.. have , ar doubt that it has taken place. It such a circumstance my take ?lace a.orh a low. pressure engine, do not you t;.inf:. ace, .f: the general calculation of Ole streag.li t:i is r• t o feta,: the usual pres.a.re to wiecti t y :- ted, more.clanger would arise Ciao' in m s. which could happen to a high pressut, r a boiler properly adapted ?-Isltt, I • . cording to the general construction at 1.A., bullets, they are so rivetted together to nulls! c pressure they are intended to bear, eisil t..c. I ways give indications of an incte..se ~f pe,s,•!te `before I should apprehend any danger itooi meanby the joints g iving tray, and the ste,; ; ;) ;, I cinq a passage through :Isem. Do you tncan to apply that to the cast iron ere boilers. The not ; to the wrought is an per The qaeition before put was meant to apply ta a low pressure engine, fitted up with a cast it As applied to ti,e cart iron holler, I sliostld say, roam being constructed to be in a less degree os eyiaitLiva force, an. explosion would vioner take therefore would be less dangerous. Less dangerous in comparison with what a high pressure boiler. Do yon mean to say, that an explosiol e! t!--1 cast iron boiler of a low pressure engine st Lich s!; , 101.1 burst by an improper degree ot press.”-:, wouhl 1;1 less dangerous than the tending of a wioo,.;!:: :Loa boiler, occasioned by a much higher degt-c.. •:t p!es. sure ?—I gave my answer as connects With the Ins ton question, With regard to the liability to danua from low pressure boilers; I take for granted, th it if a boiler is constructed to be applied to a lOW p-e , - sure engine, that a commmsurate strength will be applied to the materials of the boiler, and that in t! - .e case of applying a boiler to a high pressure engine, an adequate strength.must be used there to the press sure intended; therefore if the low I ressure boiler by any accident should be exploded, generally speata,:g, boilers made of the malleable metals ruust be nasal safer on an explosOn taking place, at least they are not calculated to . da so much mischief as the cast iron boilers. Have you made any experiments, or are yeti ac. quainted accurately with the effect of such as have been made upon the different qttantities of t ',el con sumed in the high and the 19w pressure engines, in proportion to the quantity of power produced I have witnessed several experiments on Weolt engines, where the object was to ascertain the com parative expenditure of coals or fuel in grinding crra between his engines, and the :ow pressure or ccr.df.n. sing engines, and the results were dec:dally iu of Mr. Woolf's engines. You cannot speak as to the high pressure engin , : commonly in use apprehend there is no saving of furl, or very little; there may be a little. What was the saving of fuel by Woolf's engine, as compared • with the other ?-The average effect in one case was the grinding eighteen bushels of what wits one busht I of coals; the other average effect of Et,l - and Watt's engine, or the low pressure enzittes, is the grinding of from ten to twelve bushels of wheat with a bushel of coals. . Do you know whether the power of the engines in lifting water may fairly be reckoned at the same pro portionable difference ?—Yes ; I believe they may. I do not speak from experiments ; but I have no dcu:.: as to the ef f ect; by the reports from Cornwall I a:n led to suppose it may be much greater. Ilave you seen any account of the explr,:ion Steam• Engine on board a boat in America, withil.l few weeks past ?—No ; I have not. I utticrst.l,.. there has been one. From any information you received at Norwici:, did you hear of any conduct of the manager of th.o boat, which occasioned the explosion of the boiler ? No; the information I did receive upon that subj ' e. was since we returned to Lnnclon.—( To le eeationaZ.) - -• DIED. --- On the Utast:l4.lot, in his gmb year, very highly esteem...'. William Wheeler, Lop of Winatifuld House, ureetenLite. lie possessed extensive kuowledge, with a reculbr v gour rs. energy of mind to the latest hour, united to a di:pniit , •in thr most liberal, generous, and humane. By his lamented e. eat!' tie County will experience the loss of one of iu oldest r•rdErritt . .t supporters of iudependenee. Monday, at Bath, in the 54th year of his age, tote Ar.:r.!•;• His I.ordshlp It succeeded in his titles and estate by hit • • sots, James reerani Arundel PRICE OF STOCKS YESTERDAY. Bank Stock,— Long Arms. flit 9015-16 9; • 3 peTet.Red. 804+ 221 I India Bonds lON 109 pr. 9 per Cent. Cons 8017 P; 80/ Exell.Pllls (tl4d.) 27 024 ! 81; ex. dlr. Cons. for Ac.Bll tt:l at; s I per Cent. 99f 981199# 5 per Vt Navy 1031 104 1 1051 Lottery Tickets XIS 155 . - COAL MARKE r, JULY 16. Ships at Market. Sh's sold. Prices. 34* Newcastle St SG*. Gd. to 4:s. 3 Sunderland $ Vs. 6d. to t-s. .. 1 Stone Cost 1 GM (A. 1 Fore.t of Dean Coal t SGs. ed. 0 Wet Coal 0 o'.)c. 011. 1 Cinders 1 ^35.04. HIGH WATk.I4 TO MORROW AT LONDON tuu:).,, Morning - - •• 36 *Wu. after 4 Merlon n - . $6 ... 4 .. LetIDON - . a r a e d aad piebtiskycl by Levi:. Ss :; T, Pim , I ernvie•isAr. .'