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THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[November, 



Mr. Fairbaim : Our object has been two-fold; first to inquire into tlie true 

 cause of the accident; and next, to set the public right with regard to the 

 constructionof fire-proof fabrics in future." — [Mr.Fairbairn exhibited the plan 

 of one floor of the mill, as to its bays, principal and cross beams, and arches 

 in order to aid in his explanations ; and for the same purpose we have given 

 below a copy of the diagram embodied in the joint report of Messrs. Fair- 

 bairn and Bellhouse.] 



Mr. Fairbaim then proceeded to read the report, as follows; adding ex- 

 planations as he went on, to the following effect : — 



"In consequence of a unanimous expression of feeling on the part of the 

 coroner's jury, that a full and satisfactory inquiry should be made mto tlie 

 causes which led to the death of Joseph Tweedale and others, at Messrs. Rad- 

 ciiffe's cotton mill, Oldham, on Thursday last ;— we, the undersigned, have 

 carefully examined the building, and, having noted every particular relative 

 to the walls, foundations, iron beams, columns, and their fractures, are of 

 opinion that the accident has arisen from one or two causes ; namely, from 

 the falling of one of the arches in the first instance, or, what is more proba- 

 ble, from the breaking of one of the large beams supporting the transverse 

 and longitudinal arches at the extreme gable of the mill. 



" From the evidence already adduced, it appears that one of the arches in 

 the top room fthe fourth from the old mill) was observed to sink, some days 

 previously to the accident which subsequently occurred ; this arch, which had 

 sunk about four inches, was considered unsafe, and the necessary preparations 

 for refixing the centres were immediately taken for its renewal. During the 

 re-building of the arch (of which about one-third was completed, the middle 

 being removed, and the other remaining), the building at this critical period, 

 gave way; and, as stated by one of the witnesses, the beam broke short by 

 the column, and the whole came down with a crash. Now in this view of 

 the case (and assuming the evidence to be correct), it is obvious, the beam 

 must have broken from the lateral strain of the arches, and not from the 

 weight acting vertically (as assumed) upon the beams which remained. Jn 

 confirmation of this opinion, it will be observed, that the middle beams were 

 unprotected from the lateral thrust, unless we except an imperfect wooden 

 stay, which, from its soft and fibrous nature, would easily split, or crush, by 

 the force of the edge of a flange of only one inch thick pressing upon it." 



In order to explain this more clearly, it may be necessary to refer to tlie 

 plan a little. This [marked bay 3 in the plan below] is the arch where the 

 accident is said to have commenced. The north third of the arch had lieen 

 taken out and renewed ; the middle third was taken out altogether when the 

 building fell ; and the south third was the old arch, as it had sunk. The 

 middle beam [that between bays 2 and 3, marked b, and thirteen feet ten 

 inches in length] broke oft" at the collar [at the north end]. Two square 

 pieces of wood, 4J-inch scantling, were put across at these points only [indi- 

 cating them], bearing upon the lower flange of the beam : consequently, if 

 any lateral thrust took place from the adjoining arch or arches [marked 2 

 and 4 on the plan], its tendency would be cither to split the wood, or to crush 

 its fibres, and thus to cause the beam to break. That is one way of account- 

 ing for it. I am, however, of the opinion myself,— and Mr. Bellhouse con- 

 curs with me,— that this was not the cause, here, but another, which will 

 presently come before you : — 



" Hence it follows, that the thrust of two wide and flat arches would be 

 quite sufficient to fracture the beam, and thus loosen or destroy the abut- 

 ments on each side. The beam being ruptured, it is easy to conceive the re- 

 sult which must inevitably follow such an event. From the breakage of this 

 beam, we may infer a serinus and extensive accident; but to our minds, it 

 does not sufficiently clear up the full amount of injury sustained ; nor does it 

 account for the immense crash and total destruction of the building, which 

 ultimately took place." 



I believe that the whole building came down almost instantaneously. If I 

 am rightly informed, both the side walls and the gable end fell outwards. — 

 The Foreman: Not outwards, but inwards: the walls came principally in- 

 wards, like a funnel.— Mr. Fairbaim : But I am strongly inclined to think 

 that the walls would be crushed outwards. — A Juror : There is evidence to 

 show that the walls first fell outwards ; and, on the south side, a stable and 

 several pigsties, at some distance from the building, were knocked down. — 

 Mr. Fairbaim: I did not hear the evidence ; but I made inquiries at the place; 

 and I saw, that, on the side next the engine-room [the north], the walls had 

 evidently, in falling, struck the side of that building, because there were in- 

 dentations on the bricks. On the other [south] side of the building, again, 

 at a distance of not less than six yards— [Several jurors : Oh! considerably 

 more], some buildings were destroyed by the falling walls ; and I was also 

 informed, that immense quantities of material had fallen outwards at the 

 gable end. [Indeed, it was here that Whitehead was killed by the materials 

 falling outwards, towards the detached chimney at ihe north-east comer of 

 the building.]— The Coroner: Do you not think that the beams pulling the 

 walls inwards would tend to make a collapse? Mr. Fairbaim : If the pillars 

 had given way first, it would ; but, if the pillars remained, the walls would 

 go outwards.— The Coroner : Did you read the evidence of Mills, the beer- 

 seller, who saw the fall from his house P He says : " On Thursday last, I 

 was at my house, facing Lower House Mill. I saw the [north] side next the 

 chimney begin to fall. AVhen the roof had fallen two stories, it made a stop 

 for a second or two. The outer walls then flew in, and it all came to the 

 ground.— A Juror : That is, the upper stories fell outwards; and then, the 

 walls breaking, the lower portion went inwards.— Mr. Alexander Taylor ( 



juror) : One of the firm (Messrs. Radclifle), who has not been examined, says 

 that Ihe building began to fall outwards, and ultimately went in : that would 

 be the lower part of the warehouse that went in.— Mr. Fairbaim : However, 

 it is not very material ; for I do not know that it affects the principal cause 

 of the accident at all, and it is not a question of any great moment. 



" One of the middle beams, or any one single beam of the building giving 

 way, could not, in our opinion, have made the ruins so complete ; and, hav- 

 ing reason to susnect some other cause, we were induced to institute a still 

 more minute and searching inquiry into the strenglhs and proportions of 

 other parts of the structure. 



"On a careful examination of the fractured beams, and more particularly 

 of those which stretch transversely across the building, at a distance of 15 

 feet from the extreme gable of the mill, we found a more convincing proof of 

 the cause which led to this unfortunate occurrence, 



'• These beams carry the ends of four other beam?, which extend longi- 

 tudinally from the gable on which they rest, as shown in the following 

 sketch : — 



•South. 



Fig. I, Flan of Building. 



[The figures indicate measurements in feet and inches.] 



" From the above, it will appear evident that the beams a, a, a, had to sup- 

 port a much greater weight than the beams b, b, b, 8cc. ; and consequently 

 they required to be made of proportionately greater strength. They were 

 made stronger ; but unfortunately, from inadvertency, br rather frovi want of 

 knowhdge, they were strengthened in the wrong place ; and instead of adding 

 the additional strength to the bottom flange, which is always subjected to 

 the greatest strain, it was given to the middle of the beam where it was not 

 required." 



Now, with respect to this point, if you take a beam with a single flange at 

 the bottom i and break it w ith the flange downward, we may call the break- 

 ing weight 1,000 ; but, if you take the same beam, and break it with the 

 flange upward T, you will find, that it will only carry a weight of 323 to 

 break it: consequently there is a deficiency of strength, from merely revers- 

 ing the position of the same beam, in the ratio of 1,000 to 323. But people 

 totally unacquainted with this factmightsuppose there was as much strength 

 in the beam laid the one way as the other. But it is a totally diflierent thing 

 from timber ; and cast-iron is a material so extensively used, and of so much 

 importance in the economy of building, — and, indeed, in almost every thing 

 connected with the industrial arts of this country,— that I have taken tlie 

 liberty of pointing out to the jury the fact of the great difference in strength, 

 in the same beam, between the one position and the other. 



"It is well known, or it ought to be known, to every person giving in- 

 structions for the form and construction of iron beams, that the strength is 

 nearly a proportional of the section of the bottom rib or flange ; and, accord- 

 ing to Mr. Hodgkinson's experiments, a bottom flange of double the size will 

 give nearly double the strength," 



[Mr. Fairbaim further illustrated the form of the be.ims by some model 

 drawings, not having any reference to those in Messrs. Radclifi'e's mill, but 

 which were made for a mill in Ireland, — that of Messrs. Alexander, near 

 Lough Swilly. In reference to these drawings, he said:] These beams are 

 not correct as to the perfect form of each ; but they are as near an approxi- 

 mation as practice will allow ; and, if the person who gave instructions in 

 this instance for strengthening the beams, instead of putting the additional 

 metal on the body of the beam, had attached it to the bottom rib, these beams 

 would have.been made one-half stronger, or rather more than that ; but un- 

 fortunately the additional strength, in this case, has been put upon the mid- 

 dle of the beam. In order to explain the nature of this beam, I may observe, 

 that, if you take a beam of any dimensions, and suppose it supported at the 

 two ends, and then lay a weight on the middle, you cannot break that beam 

 without pulling the particles of all the bottom part of the beam asunder, and 

 you must break the upper flange by compression or crushing. There is a 

 point called the neutral point, where the particles are neither extended nor 

 compressed ; you cannot break it without bending ; and you must disturb all 



