1846.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



279 



later period, the committee of 1844 received from that gentleman this fur- 

 tlier statement : " Without hesitation I say there is no art that can make 

 the piers of this bridge so secure as I could have made a new one." 

 Nevertheless, upon a review of all the case, he added : " I did not doubt 

 as to the security of the whole superstructure. When I say this, I must 

 at the same time allow, that the sinking which has taken place in the 17- 

 feet east pier, after the water was admitted within the coB'er-dam, is a 

 drawback." meaning, of course, the only drawback, " which has at all 

 raised a doubt on my mind ;" a sinking, be it remembered, which has gone 

 down nine inches, and has left that pier three inches out of the perpen- 

 dicular: "but ever since last October that pier has been, as every other 

 part of the brid^je has been, perfectly motionless : and therefore I have 

 reason to think that the cause which created that movement in the 16 and 

 17-feet piers is at an end, and that these also are secure." At this time, 

 the 16-feet pier had gone down two inches, and the 17-ft. pier nine in.: 

 " all the piers," indeed, " sunk a little during the operation of driving the 

 piles." 



The confidence, however, or to use Mr. -Walker's wordsin another place, 

 ** My faith, which amounted to conviction previously." {i. e. to the sinking 

 in October, 1S13), " was somewhat shaken" by that sinking; but he adds, 

 " it is proper also to say, that my confidence has revived, by the entire 

 freedom from all movement since that tiaie," viz. up to the date at which 

 he was then speaking, 10th June, 1844. If, however, the confidence re- 

 vived solely because the piers had ceased to sink, it must, of course, die 

 again when they again begun to sink. And this is the fact. The sinking 

 has begun again; and, though in no one week considerable, or indeed ob- 

 eervable except by very nice tests, yet the aggregate sinking in the course 

 of mauy weeks becomes perceptible to the eye; and above all. as it is pro. 

 gressive, must, at some period, terminate in the destructiou of certain por- 

 tions of the bridge, even if it do not endanger the whole fabric. So early 

 as 1837, Mr. Walker's recommendation to the commissioners, as already 

 seen, had been to build a new bridge, if the funds could be obtained. On 

 the 7lh May, 1845, he stated to the commissioneis, still more strongly, — 

 ** to the reasons I then gave for recommending the new bridge, there is to 

 be added the bad foundation which has caused the sinking in the two 

 piers ; for even half an inch in two years is enough to prove the want of 

 perfect stability, and to weaken that confidence which I ought to feel in 

 order to justify my recommending an outlay of £100,000, in addition to 

 the £90,000 already expended. 1 have before staled, that all the othe 

 piers, which have been finished, are secure ; but two piers on the Surrey 

 Bide next to the defective piers, remain to be coder-dammed round and, 

 piled ; and if the sand under those two be of as loose a nature as those 

 adjoining, they may cause further trouble and expense. Should they re- 

 quire to be taken down, the difference between the partial plan" (i. e. con- 

 tinuing the system of repairs) " and the entire renewal" (i.e. the removal 

 of the old bridge and the construction of a new bridge) ** will be consider- 

 ably lessened." The causes which induced Mr. M alker to recommend a 

 new bridge in 1837 and in 1844 and in 1845, have not ceased to operate. 

 The sinking in the 17-feet pier since the 7th May, 1845 to the 19th May, 

 1846, has been 1 J inch, and in the 16feet pier about 1^ inch ; and it con- 

 tinues in both. 15y the report of Messrs. Walker and Bulges to John 

 Clementson, Esq., Secretary to the bridge commissioners, dated 20th July, 

 3846, those gentlemen state that they have this day taken the levels of the 

 piers of Westminster Bridge, and have to report a further sinking of 

 fjths of an inch in the 17-feet east pier, and ^th in the 16-feet east pier, 

 since their report of the 6th instant." [6lh July, 1846.] They go on to 

 say, " The movement of ^ths of an inch in the 17-feet pier is double what 

 -we have had occasion to report for a considerable time. The continued 

 sinking in the two piers has affected the stones of the 72-feet arch which 

 rests upon them, an open joint being perceptible in the soffits between two 

 of the courses near the crown, and one of the south-face stones having 

 dropped down about half an inch." Messrs. Walker and Burges concur, 

 accordingly, in the statement, " that a way or thoroughfare over the river 

 at Westminster, consistently with the safety of the public, can be best 

 secured (or perhaps we ought now to say can be secured only) by a tem- 

 porary bridge ; and that no time should be lost in proceeding with it." 

 More than a month earler (11th June, 1846), Mr. George Rennie gave, in 

 substance, the same opinion, namely, that no time should be lost in making 

 ariangemeuts for the construction of a new bridge ; and being asked, 

 ** Might not the present bridge serve as a temporary accommodation while 

 another bridge is being constructed ?" he replies, " It might;" but he adds, 

 " with all the chance belonging to it." 



It is true that Mr. William Cubilt, the contractor, whom your committee 

 felt it to be their duty to call as their first witness, inasmuch as the pro- 

 gress of the New Palace was a matter, as has already been observed, of 

 comfort and convenience to the two Houses of Parliament only, whereas 

 the safety of the bridge was of paramount importance to hundreds of 

 thousands of the Queen's subjects, stated in answer to the second ques- 

 tion, " 1 do not appreheuJ the bridge to be otherwise than safe." • • " I 

 do not mean by that, that it is in a state of perfect stability ; that there 

 may not be from time to lime slight settlements in it : bui I am very 

 strongly of opinion that no settlement will ever take place to a degree that 

 should endanger the public safely." 



The same witness, indeed, had stated in 1844, that he thought the bridge 

 may last for two or three centuries ;" " that the bridge, W/th a very mode- 

 rate repair from time to time, is captible of carrying the piildic sufely for 

 centuries to come ;" and he added, accordiugiy, " I know uo reason why 

 it should be pulled down." 



On (he extent, however, of the knowledge of the witness as to the facta 

 connected with Westminster Bridge, it is due to the other gentlemen who 

 gave a very opposite opinion, to slate, that Mr. W. Cubitt, being asked 

 whether he can state the depth of the river at Westminster Bridge now, as 

 compared with its depth before the removal of old London bridge, an- 

 swered, " I cannot ;" and being further asked, " Have you ever understood 

 that it has already (1844) deepened as much as five or six feet? ' replied, 

 " I have never hard such a thing : if that has been stated, it can only be 

 in one particular place, where, from some cause or other, there has been a 

 gullying out by a peculiar current:" and when again asked, " You are 

 not, however, aware of the depth which has been given to the river by the 

 removal of old London bridge ?" he replied, " I am not aware of it ; but I 

 am pretty sure that it has not given an average of 18 inches." The com- 

 mittee understood, of course, that in this answer Mr. W. Cubitt was 

 speaking at the time of the locality in question, namely Westminster 

 Bridge, and not of the Thames at Staines or Walllngford ; and therefore 

 proceeded to put the following question : ■' You conceive that anything 

 less than an average of five or six feet would not endanger the security of 

 the sheet-piling round the piers, by which they are surrounded?" to which 

 Mr. W. Cubitt answered, " I rather hesitate in giving the precise line : if 

 it came to five or six feet I should begin to feel uneasy, if I was sure it 

 ever came to that." It appears, by sections of the river taken by Mr. 

 George Rennie, and laid before this committee, as furnishing a very curious 

 and interesting view of the changes produced by natural causes in the bed 

 of the river, that between 1823 and 1835, the river, 50 feet below West- 

 minster Bridge, had deepened between six and seven feet ; proving the 

 tendency of the river to "engineer for itself," to use Mr. Page's expression, 

 to a greater degree than was previously anticipated; and this measurement 

 near Westminster Bridge proves that the very case had happened which 

 as Mr. W. Cubitt stated, would have made him " begin to feel uneasy," 

 namely, that the bed of the river had there deepened at least five or six 

 feet : it fact, it has done more, inasmuch as, " by a longitudinal section of 

 Westminster Bridge which appeared in Appendix 15, G. 1, to the Report 

 on the Thames Embankment, and upon which," said Mr. George Rennie 

 in his evidence, " 1 have coloured by a dark line the existing bed of the 

 river in May 1846, it will be seen that the sixth and seventh piers from 

 the Surrey side have their fouudations exposed eight or nine feet." 



On the whole subject of the effect which the deepening of the river or 

 any other cause may have had iu unsettling the foundations of Westmin- 

 ster bridge, and consequently its superstructure, the committee feel it to 

 be their duty to recal two circumstances to the attention of the House: 

 first, the settlements which did take place in the autumn of 1843, which 

 as already noticed, caused the bridge to be closed and shut up for car- 

 riages during a portion [of the winter following; and secondly, that the 

 favourable answers already quoted as to the stability of the whole struc- 

 ture, depend on the assumption that the whole structure is to be subjei:ted 

 to the same process and system of repair which has already been applied 

 to parts. Now, the amount of the contract — remaining so to complete the 

 repairs — was, in 1844, £52,870, together with a lurther sum of £40,000 

 to make the bridge of the same width as London bridge. This aggregate 

 of £92,870 was therefore necessary, in 1844, according to the then views 

 of the commissioners, to the repairs of the existing bridge ; aud might have 

 been saved accordingly, and made applicable to the construction, in part, 

 of a new bridge, if the repairs had been then discontinued, and if a new 

 bridge had then been substituted. 



In addition to this, it must never be forgotten, that Mr. W. Cubitt being 

 the contractor for the works commenced in 1838, gave evidence as strong 

 as that of any other witness, on the question of the original vice of the 

 foundation. In 1844, he referred " to the original defect in the surface of 

 the foundation ;" adding, " I mean that it never was correct and proper." 

 "There was one pier which had always been called the sunken pier; that 

 was the one they were obliged to uuload when the bridge was first built. 

 Then these two other piers in the bridge which were called sinking piers: 

 they had that name given to them because they had been in the habit of 

 sinking more than others." And being asked, in reference to a subsidence 

 of nine inches in one of the piers, whether such subsidence shakes his 

 belief in the future stability of the foundation, he replies, " 1 always had 

 au impression that the bridge would be liable to sink a little;" and being 

 further asked, whether, " When you say ' a little,' do you consider nine 

 inches a great or a small subsidence ?'' ue replies, " I consider nine inches 

 to be a great deal ; but with reference to an arch of that form aud with 

 stones of that thickness, it is of very little importance with regard to the 

 safely of the bridge." While, however, Mr. W. Cabitt states, that, so far 

 as the original defectiveness of the foundation is concerned, tlie bridge is 

 sufficiently stable for all purposes for which it is required, that no disaster 

 ever can accrue by which the public would be damaged from that cause, 

 he does not retract his preceding opinion, "that the bridge always must 

 be an imperfect structure" in reference to the mode in which it was built • 

 and, though be may contradict the opinion of others, he cannot gaiusav 

 the fact, that the bed of the river has been gradually deepening, and the 

 foundations of the bridge abraded aud laid bare in co;!stquence ; and the 

 committee feel, that if this be so, Westminster bridge cannot he "as stable 

 as it ought to be. 



The very remedies, indeed, which have been applied to strengthening 

 the foundations of the piers may in fact ha\e loostced them, by loosening 

 the ground on which they rested. Even so early as the 16th of May, 

 1823, the late Mr. Telford himself admitted, in reference to bis own sug- 



36' 



