1843.1 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



195 



alao good. There ii another straight piece between the two ends. 1 think generally that 

 the quahty of the endi is not according to the ipeciacations, nor are they in my opinion 

 proper for tlie purpose. Had any sufficient means been used to prove and test them, tin- 

 inferiority ol this iron must have been at once discovered. This is a piece of one of the 

 ends, whicli IS a very open, coarse-grained, and inferior piece of iron, and which broke 

 when the blacksmith referred to was applying a hammer to the middle of the bar; the 

 part which he did not slrille broke like a piece of cast Iron. The blow was applied, re- 

 member, at some distance from where it broke. If care hud been taken to test this iron 

 properly, it Is impossible bui what this defect must have been discovered. No one could 

 have eipected that It was going to break, but It did. Another bar was Ukeii by my di- 

 rection lor the purpose of testing it as to llbre, and it broke in pieces just in the way n 

 carrot would do, and did not b.iul like « piece of stout lir timber, which it would have 

 done had It been sound. I shall now make a lew remarks upon the strength of the bridge, 

 a> compared with the loud. Taking the loud at the time to be ail on tlie south chain, I 

 and by calculation lh.it the two rods of 2J Inches by i are capable of supporting a tempo- 

 rary load of 5(1 tons without Injury. Of course, I am assuming in that that the bridge 

 should be properly constructed. I need not say, that in order lo orrive at anytiilng like 

 accuracy, a great deal of caiculatioii is required, because the deflection of the Irou and the 

 •pan of the bridge ought to be taken into account. I find that the strain, taking 4011 in- 

 dividuals at an average of seven stones each, and allowing for the weight of the bridge, 

 was, at the time of the accident, about -14 tons. Therefore, but for the defect in the 

 iiuaiiiy ol the iron and in the workmanship, the strength of the bridge exceeded the load 

 upon it ; but even then the excess was not sufficient where the effects of failure are so 

 Important. I say so because experiments are generally made witil good iron, and at all 

 times large allowances ought to be made for Imperfections. I( we suppose any of the 

 pieces to lie bad, iis was the case here, tben we have the strength less than the strain. The 

 bridge appears to ms to have been by no means too strong as originally formed, and the 

 additions made to Its width have been In the present case exceedingly Injurious, by the 

 weight being placed outside the suspending chain. The weight had therefore to be car- 

 ried entirely by that chain in place of being equally borne by all, which is the case when 

 the weight is within the chain. In reference to the sufficiency of the bridge to carrj the 

 greatest load which could he placed upon it, I hnd that its strength is somewhere a li'tle 

 above the weight which it would carry, but so small as not to be practically sufficient even 

 witliout any allowance for imperfections. It is proper, however, to say that the question 

 Is not how many people can be packed • en masse' upon the bridge, although even that 

 conlingency ought to be provided for. After the bridge was widened the strength exceeded 

 the strain, of course, less than it did before ; but. even before, it does not appear to me to 

 have been sufficiently strong to ensure perfect security, supposing a mass of people to have 

 been packed upon It in the woy in which I have described. It appears that on other oc- 

 casions a very great number of persons had been upon the bridge, and that it had borne 

 them without falling; the coroner has Informed me that he has known twice or thrice the 

 number upon it that was collected on the occasion alluded to, aud therefore we h,ive It 



"■■'''■ '"- "i^ I""'' >' 'hat time the strengtli of the bridge was adequate. It is also 



in a bridge has been frequently loaded to the utmost which it will bear it 

 and weaker each lime, and the bridge may ultimately give way, although 



evident that for the load at that 

 evident that when 

 becoaies weaker 



at first it was sufficiently strong to resist the weight put U|'on it. 1 InTve now only a (ew 

 remarks to add in the shape ot general conclusions Irom what I have stated, and they arc 

 these : — ' 1 ^ 



1. I consider the immediate cause of the accident to have been a defect in theioiuin» 

 or welding of the bar which first gave ivay. ° 



J. That the quality of the iron and the workmanship, as far as I have been able to exa- 

 mine mom, are delective; and I believe that the accident would not have happened had 

 the work been properly examined at the time of construction. 



3. That the widening appears to have been made without sufficient reference to the 

 °t acted asTn\ rayi'tlon"ot- the "evil "'°'^'" "'"''''' " ^"'^ '" '"'''''°"' "'"' "'"'f'"-^ ">»' 



4. That in the original construction of the bridge, the cosualty of a great load all on one 

 not appear to have been rantemplated ; If it had been, I think that the links on 



^'han the two bars, any one of which was unequal 



side does 



that side would have consisted of 



to the loati which the bridge was likely to carry? 



' ""' '' ""' stigation I have received every possible assistance 



... icuments which were in his nosseasion • thi« hHR 

 enabled mp to mm. In tho r.n„,.i„.i„„. I i j.... , , .. ' '". PV»»eii3ion , tois nas 



Bd to add, that In thi . ___^_ _.^ 



from Mr. Cory with reference to all documents whk'h 



enabled me to come to the conclusions I have done In less'time," and Ihope with a greater 

 jpproximation to accuracy, than otherwise I could have done. I believe I have said all I 

 have to say as far as the case has gone. I can only add, that under the direction of Sir 

 James Graham any question which any gentleman might put to me I shall be very glad 

 to answer Perhaps I may also add, that the whole weight of the bridge has been tak.n 

 with great accuracy by Mr. bcoles, and that the addition to the widthTas far as its own 

 weight goes, Is comparatively unimportant. The weight of the bridge, including the sus- 

 pending chains, before the additional width was added, was 17 tons 14 cwt Sara ■'51b ■ 

 with the sddltional width and the railing added, its weight was 2U tons 8 cwt. aib.rmak^ 



3Xr^?„'l°.1..°„ °Jk''T'-, ?'/"' °f ■' i^. 'he footway being outside the chains, 

 and therefore throwing the whole load upon the two suspending chains, without any par 

 being thrown upon the chain on the north side »""ijiJoii 



'."wh'"" " ''.""""n' P"' by Mr- Evans (a barrister at Norwich, who attended to 

 witch the proceedings on behalf of the owners of the late bridge), Mr Walker said— I 

 .aw in the original specifications that all the wrought iron shoold be proved by heatinu it 

 red-hot; and, if this had been adopted, we should not have had the weldings which wo 

 have seen to-day. I observe, in the specifications, thnt all the materials to he used in the 

 before.mentioned works should be of the best quality, and that it should be in the cower 

 «f Mr Cory, or his surreyor, to reject any mHierials which he or they might deem insuffi- 

 cient for the wcrks. It was most undoubtedly the duty of the person uridertokimr to be 

 the surveyor of these works to have ascertained by soma such iiieans as I have described 

 the quality ol' the Iron, and the manner in which it had been welded. If the survevor 



rJiSi"'°?i, '°fi ;'''°'^''!;'T'' ''"'° ""''*' """^ =« the contract carried out ac; 

 cording to the specifications, had done so, this accident would not have happened, In all 



h^H , /-H "T" '^',!.''l'^"^'5' """" of -"^""ity h^v been discovered. If a peJso 

 had watched, as he should have done, the welding of every link, this defect would not 

 txave arisen; the defect in the quality of the iron must havi been very apparent to any 

 />ne at all acquainted with the subject. I have made my calculations as to he weigh? of 

 iurtrT'^-^T bridge upon six to the square yard. I should think that, practically, 

 Bufh crowtbng seldom. If ever, occurs. It is with reference to such packing that I have 

 Bpoken. and I thinfe the bridge would hardly have borne It I think even it as I believe 

 to have been the case, the crowd consisted chiefly of women and children under 14, that 

 L'„,?h iy^TAr """^"Se »?^8ht. It is too much of course for children, but not 

 enough for a good fat woman It .. perUapa rather a large average. I took it partly be. 

 carse t has been frequently adopted before. Looiing =t the contract generally, I do not 

 think the gentleman who built the bridge origin.ily had taken the necessary precauliZ 

 to hate the work properiy done, inore particularly as regards the mode of doing it. I 

 think the contractor silould have piven the engineer or inspector of the work the power of 



5?,'. cf.l'i't^ ■'" '"* " "",^1," ■" ■""'""' "■'"" "• ' "" -»" ''"" 'hat in the contract 

 The clause which empowers the engineer to reject any materials which he might deem 

 unfit gave this power indirectly, and in a manner; but I think the surveyor ought o 

 have the power to do so without siich a clause as that ="ive)ur ougui lo 



.h?/ "'^./'"•yT'" my opinion, and speaking from the general result of experience in 

 fer" rrt"; 'g^Vi°r 7,,\?"„:',";H^:'r,^°,^.".^> -t-^l '? ^^co..Uy, the? were : 

 Xh€ 



... -. . . '"I''<^!f P"^"') "M supplied at Yarmouth aod'usedVcre. 



elding, or joining, wos moat likely done here. The difference between good and 

 bad iron was shown mainly by the breaking ; good iron broke like a piece of good lir tim- 

 ber, bad, as I have before said, like a carrot-it 8na])» In two. H. had estimated the 

 number on the bridge at 4tW, because the alatements he had heard were 3U0 and 500 If 

 we"ghl'on thOridg" ■""" ' *■"" ' ""'^ '" ''"'''" "'''•'"'^tU from the Mtimntcd 



The following is tlie unanimous special verdict of the Jury .— 



"That the deceased came by her death by the falling of the suspension bridge across 

 the River Bore in this borough, on the 2nd of May, 1845. That the falling of tlie bridte 

 was attributable Immediately to the defect In the joint or welding of the bar which first 

 gave way, and to the quality of part of the Iron and workmanship being Inferior to the re 

 quirements of the original contract, which provided that sucli should be of the first 

 quality. Although the jury do not wish to ada more to their verdict, they wish to exoren 

 the fullest coiieurrence in what had fallen from the coroner as lo Ihe facilities which had 

 been afforded by tile Messrs. Cory In the prosecullon of this inquiry, which bad been so 

 scientifically conducted by Mr. Walker, who had been deputed by Sir J. Graham to come 

 down and examine Into the carse of the accident. They are of opinion that every possl. 

 ble precaution has been taken by the original proprietor of the bridge, and that had the 

 clerk of the works performed his duty in tho proper examination of the work the calamity 

 winch they now deplore would have been prevented. They beg also to express their 

 sympathy with the present proprietors of the bridge, whose entire conduct has reflected 

 the greatest credit upon them, in the kindness they had shown to the turvivors of those 

 wlio had been lost by the sad event." 



DIISCEI.I.ANEA. 



Stram Navigation.— In the 1 louse ol Commons in the debate on the Nav» 

 Estimates, Sir G.Cockburn stated that he was in hopes before long to have all the ves.eia 

 of the navy fitted with screws instead of paddle wheels, and as an instance of the efflclencv 

 of the screw, he mentioned that in a trial of speed the Iluttler bent the Vesuvius went 

 round the Bass llock and turned hack 20 miles before It met again the latter vessel ' 



UtUMii OF iwii Spi.EMiin Ikon Steam Kuigates at Livi;bpool— Two fine 

 ships of war constructed of iron were launched on Wednesday, April 23. at the buildinir 

 yard of Messrs. Thomas Vernon and Co., North Shore. Both ships have been constructed 

 on the most approved modem principles, with patent rib.lron ; both vessels are from the 

 same moulds,;^ of equal tonnage, a"d to be provided with equal steam power-being what 

 may be termed sister ships ; and (still more curious) that they have been constructed fer 

 two of the most exalted potentates of the European coutiilent,—the Emperor of Pussia 

 and the King of Prussia, aud these standing somewhat in relations of rivali-v Each wis 

 built to the same measurement, as follows:- "vu na. 



Length over all 185 feet 



Breadth, or beam 29 



Depth of hold 17 " 6 In. 



Burthen 750 tons, old measurement. 

 -In niodel they are almost precisely alike, with very fine extremities, but with that pecu- 

 liar fulness of bilge and slight rise ol flooring amidships, which is found, though somewhat 

 contrary to the usual conception of the ' beau ideal' in naval architectm-e, to imZt ,1? 

 bility and speed, especially to steamers, besides additional buoyany, suitlni; then, fnr n. 

 collar navigations. The whole of the side frames or ribs, and the deck b-uTs are"^'? 

 ^.?r Th- Vernon's parent iron, (a decided improvement on the angle-iron hitherto In 

 use.) I his new form of ribs has already been paitially employed in other vessel, 

 with satisfactory efl-ect ; but In these it Is used in every part where it is apnlfcable ar^d 

 combines the greatest strength and non-liability to fracture, with the utmost attainable 

 buoyancy. The plates of the garboard streak are J inch in thickness, and decieasini a 

 little as they rise, are at the gunwale, or covering board, 4 Inch. They are so rivetted and 

 secured to the ribs, which are strung together in every possible manner for cfficiencv that 

 the whole IS, as it were, one solid mass of laelal. The bottoms, to light water mark are 

 clencher-built or lap-jointed, and the sides flush or carvel, and present a smooth 'and 

 finished appearance. They have each gilt eagle heads, and are made good from the bui. 

 wa-ks to the extreme point forward,— a comparatively modern improvement which irive, 

 a vessel greater buoyancy when meeting with a seaway a-head. The ve>.His a^e both 



MLTs'Rnfrr'„rM "'!! k' ""^i" *""' ■*"' '"«''"' "' 'I""' »'"'" f'O" the work, o 

 AiBSars. ijury, Curtis and Kennedy. * 



The Fyramius Eclipssd.— The A'a/^ia; /„/w;<^«.i,cer fan American paper) 

 contains a long letter from Mr. Pickett at Lima, commenting upon discoveries of Very 

 extraordinary ruins said o have been found by Judge Neito, in the province of Chaoha. 

 r!n?.';' h IM- "" "■''"'•'"S eipedltion. In making a survey of the country he found at 

 Ceulap a building of most extraordinary character, which he describes as a wall of hewn 

 stone 660 feet in width. 3,600 feet in length, and 160 feet high. The edifice being sohdln 

 the interior for the whole space contained within 8,366,000 feet of circumference which it 

 has to the heforementioned height of 1.10 feet ; is solid and levelled, and unon It there I. 

 another wall of 300,000 feet in circumference ta this form, BOO feet U, length and 50 in 

 breadth, with the same elevation (160 feet) in the lower wall, and, like It, solid and levelled 

 to the summit. In this elevation, and also that of the lower wall, are a creat manv habi 

 tations or rooms of the same hewn stone, 18 feet long and 15 wide, and In these rooms as 

 well as between the dividing walls of the great wall, are found neatly constructed ditches 

 a yard or two-thirds in length, and half a yard kroad and deep. In which are found bone, 

 of the ancient dead, some naked, and rome in cotton shrouds or blankets, of very firm 

 texture, though coarse, and all worked with borders of difl'erent colours. If this descrin 

 tlon be authentlc-and we have no reason to doubt it-thl. building must be the greatest 



IL dt.Tri '?■ '" 1°"" °!r'- . ''''^ '"""'" °f ™"""B '" E^P' 0^ Persia to equal It.* From 

 the description it must have been avast tomb, but whether erected by the Indians, before 

 the bpanisb discovery or by remote generatioas, cannot be decided; yet the Judge saya 

 that the ingenious and highly wrought specimens of workmanship, the elegance of the 

 cutting of sonae of the handsomest stone, the ingenuity and solidity of the gigantic work 

 all in stone, the elegant articles of gold and silver, and the curious wrought stones found 



whrhrHl .H •^f""'"'™ "'^' "" "^■■'■i'o'-y"''^ occupied by an enlightened nation, 

 which declined m the same manner as others more modern; as Babylon, Baalbec and 

 the cities of iyria ; and this, he says, is evidently the work of people from the old world, 

 as the Indians had no Instruments of iron to work with. 



Bridge across the Alleghany.— The PitUbunrh Chronicle gives an ac- 

 count of the manufacture of a suspension bridge across the Alleghany. The bridee la the 

 work of a mechanic of that city. The whole will be finished by the 1st of Anrfl The 

 suspension ropes, which extend from pier to pier In the form of an inverted arch 'are to 

 consist of seven strands of wire, each strand being about three Inches in diameter' Four 

 fifth n ',^ r* ."'"""'y flhi'hed across the entire length of the structure, and the 



fifth will be completed to-day. The ropes will tlien be wrapped In annealed wire. (No 

 14) which will render it one solid mass, and as each individual wire is varnished before it 

 IS put across, and as the whole will be painted when finished and wrapped It will be im 

 pervious to water, and consequently not liable to be weakened or Impaired by the weather 

 On these two immense wire ropes the structure is to be suspended. But this la not the 

 only reliance for strength. The trunk Is to be constructed from pier to nier-the .ide« 

 being of solid lattice.work-that is, strong beams placed in this form-XXX The bean,, 

 are to be placed contiguous to each other for greater strength, so that when finished the 

 trunk alone, without the wire-ropes, will be a firm and strong structure, capable not onl? 

 of austaining us own weight, but also or bearing up as much additional work as a lattice 

 work would do. In effect, the trunk is a lattice- work bridge without arches. The ropes 

 being suspended across strong stone towers placed upon the piers, are In fact inverted' 

 arches, capable of sustaining more than double the additional weight which tlie letting In 

 of the water would place upon the trunk, the trunk Itself la au independent, strong, and 

 irnmovable strncture. so that when finished the aqueduct will not be liable to be moved 

 either from the swell of water or the eftect of storms. The wires are carried across the 

 river, from one pier to another, by a wlieel which traverses the whole distance upon rones 



Zlf ". r^i ' 7'" '""" i"', ■■"',' " " «°"- '^'"' ^P" "" "o'"^" ''f horse-power. The 

 splices of the wire are made by placing the two ends together and winding them with fine 



affect thcTpUce'"' '' '^""^ '" """'^^^ """ * "'''^''"" '"" '" ''«^'' ">« wire will noi 



