164 



THE CIVIL ENGINEER AND ARCHITECTS JOURNAL 



[May^ 



loaded, at any spason of the year, to a creator ilepth than 4 feet, or 4 feet G 

 inches, for navigating the river alx)ve Gloucester ; and if it be said that this 

 arises from the want of water. 1 would reply, that if it were more convenient 

 or economical to sail these craft at a greater depth, it would surely le done 

 during the nine montlis of the year when the depth of water is ample for it. 

 I feel satisfied that if a depth of 5 feet, or fy feet 6 inches at the most, of water, 

 could be obtained, and maintained during these three months of the year, it 

 would, for the con.siderations above set forth, be found fully sufficient. In 

 this case, the whole of the works, the dredging, the dams, tlie locks, tlie cuts, 

 the equalization of the area of the channel, all might be proportionately 

 dimini.shed, and jierfomicd at a considerably less cost. In dredging alone, 

 about 150,(JU0 cubic yards might be saved, (being upwards of one-half the 

 whole quantity at the 7 foot 6 inches depth,) and the annual cost of manage- 

 ment and maintenance would be much lessentd ; and I think it probable, tliat 

 this diminished plan might be doiie and upheld at a cost that would not re- 

 quire the imposition of more than an equivalent toll for the benefit conferred 

 upon the trade. The toll necessary to pay the interest on the money to be 

 expended in carrying out the larger plans of the " Severn Navigation Im- 

 privemeHt Association.'' and in upholding the works, I should fear would 

 press very heavily upon the trade, esi>ecially as it would be levied throughout 

 the year upon all classes of vessels, the greater part of which, from their 

 light draft of water, would derive a comparatively small advantage from the 

 measure. 



These are weiglity considerations for the Canal Company ; .and if it be. as 

 I have frequently heard it advocated at your board when any suggi stion has 

 been made to raise tlie tonnages of the canal, that the smallest additional 

 imposition of toll on those articles which form the bulk of the trade upon the 

 canal would be ruinous to it, the same effect would result from the imposition 

 of any toll for navigating Ihe river, if it exceeded the limit of the loss sus- 

 tained by the trade from the impediments existing in the navigation of the 

 river. 



The only other points that I have to allude to are — 1st, that the notices of 

 the intended application to Parliament are for power to improve the river 

 from the Lower Parting upwards, whereas the deposited section shows an in- 

 terference with the river only as low down as the lock of the Gloucester and 

 Berkeley Canal in one branch, and the lock of the Hereford and Gloucester 

 Canal in the other branch of the river. At the meeting « ith the promoters 

 of the measure on the I6th of December last, an e::pIanation of this discre- 

 pancy was asked, and it was replied that there was no intention to touch the 

 river below the points above named, neither «ould they obtain power in their 

 Act to do so. Secondly, the removal of the Maisemore shoal, in the Over 

 branch of the river, to the depth shown in the section. This shoal, it was 

 pledged, should oidy be removed to the depth and width necessary to accom- 

 modate the vessels navigating the Hereford and Gloucester Canal. It ismost 

 important to the interests of your canal that the parties should be kept to this ; 

 for any interference with the shoals between your luck and the Lower Part- 

 ing, and with the shoals in the other branch of the river, would .seriously 

 diminish the depth of w ater in the Gloucester branch of the river, and conse- 

 quently over the sill of your lock, and ultmiately render it necessary to place 

 (he sill at a lower level, which, if ever needed, will be a work of considerable 

 difficulty and expense. 



For the reasons above stated. I can neither approve the modv by which it is 

 proposed to improve Ihe navigation, nor the extent to which that improvement 

 is proposed to be carried ; believing the mode inapplicable to the character of 

 the river, and the extent more than is required by the trade. 



W. Clege.im. 



Saul Lodge, 5th January, 1841. 



Report addrcsatd to tite Committee of the Gloucester and Berkeley Canal Company, 

 on a Bill now in Pariianievt for the Iviprovement of the River Severn, Bif 

 James Walker, LL.D., F.R.S., L. 8; E., Civil Engineer. 



Gentlemen — Since I received your resolutions and the communications 

 from Mr. Brickwood, I have given my attention to the plans and sections 

 which accompany the application to Parliament for the improvement of the 

 river Severn, with Mr. Cubitt's report in explanation of the scheme and lis 

 advantages, and also Mr. Clegram s report to you, with other documents and 

 papers on the subject. 



In December. 1836, Mr. Rhodes, the engineer to the then proposed Severn 

 Improvement Company, accompanied Mr. Cubitt and me on a view of the 

 river. There had been a high (lood ten days before, and at the time of our 

 view the water w as from eight to ten feet above the summer level. Ever 

 since I received such recent instructions as I felt justified to act upon, the 

 floods have been still higher, so that 1 have not had the opportunity of seeing 

 the river in its short-water or summer stale which would have been desirable ; 

 and my report must be taken, with allowances for this disadvantage, as to 

 knowledge of facts and otherwise. 



Atr. Ciihitl's I'lnii.—Mr. Cubitt's plan is well described in his report. It 

 diders from that of Mr. Rhodes in his plan first deposited, when a ship com- 

 munication to AVorcester was intended, in leaving out the weir and works 

 Mr. Rhodes proposed near Gloucester ; in placing the first w eir, that near 

 Upton, about a mile higher up the river than Mr. Rhodes at one t'me pro- 

 posed, and about three miles lower tli.an Mr. Rhodcs's last proposal, as I un- 

 derstood it from himself;' in placing a lock and weir below Worcester, and 

 below the entrance of the Birmingham and Worcester Canal, instead of above 

 that entrance ; in placing the uppermost lock, that nearest Stourport, in Ihe 

 river, and the weir in the new cut, the reverse of Mr. Rhodes's plan ; in in- 

 creasing the length of all locks above Worcester from !)0 to 100 feet, and 

 diminishing Ihe width from 24 to 20 feet. I observe also that the works are 

 now to be executed, not by a Company, but an Association, and if this word 

 be, as respects the objects, synonymous with Tnist or Commission, I think 



" I extract this from a note made at the time, but I am informed that Mr. 

 Rhodes's plan (previously deposited) shows the weir in the lower situation. 



the change of character a decided improvement, for the idea of locking up 

 the Severn in the hands of a joint stock company always appeared tome 

 very objectionable. 



Trade of the River Severn. — The River Severn, from its position in reference to 

 the Bristol Channel, from the very great length for which it is navigable, 

 from the numerous canals that connect with it, and which supply the wants, 

 and take oft' the natural products and manufactures of several of the most 

 densely inhabited and richest counties, and from the great extent of country 

 of w hich it is the great drain, is in point of importance inferior to scarcely 

 any river in the kingdom. Below Gloucester the river suddenly spreads out 

 to a great width, and partakes more of tlie character of an estuary, consist- 

 ing of sandbanks and shallow, shifting, tortuous channels, and a lift of tide 

 that is scarcely perceptible at neaps. 



IJence, in its natural state, the Severn was not, w ithout great danger and 

 delay, navigable for many miles below Gloucester, but for the smallest de- 

 scription of vessels ; Bristol was, in fact, the port of Gloucester. The Glou- 

 cester and Berkeley Ship Canal, which was begun by individual subscriptions 

 in 1794, and which, through want of funds, might, but for the liberal loans 

 from the Commissioners fi.r the Loan of Kxchequer fJills for Public M'orks, 

 have been a ruin at this time, was opened in 1827, and has removed the above • 

 evil as high as Gloucester. Ships of very heavy burthen, say 500 to 600 tons 

 register tonnage, are now docked close to the city, and an impetus has been 

 given to the trade of the town and of this portion of the kingdom. In this 

 dock by far the gre.iter part of the ascending and descending inland trade is 

 transhipped into or from canal boats and barges — the remainder is conveyed 

 in Trows, which load chielly at Bristol, pass through the Gloucester Canal, 

 and go up to Worcester, thirty miles, or to Stourport, which is twelve miles 

 higher. 



Proposed Improviments. — It is upon the portion of the river between Glou- 

 cester and Stourport, that the improvements are now proposed, and notwith- 

 standing my limited -know ledge, I feel justified in saying, that whether as 

 respects navigation or drainage, this river has been most greviously neglected, 

 that it is capable of improvements, and that it ought to be improved. At 

 present we nave a river of the importance I have named, upon portions of 

 which the track-path (if it deserve the name) is covered with water, .so as to 

 be impassable whenever there is any flood. In short-water time, again, the 

 shoals are such, in many jilaces. some even below Worcester, that a canal 

 boat of 24 tons burthen, and drawing under four feet, the great trade of the 

 river, cannot make certain of getting over them, but is liable to considerable 

 delay. These shoals are local, and appear to consist of material w hich might 

 be removed, and being removed, and tlie width regulated, would not be likely 

 to retuin, as is proved by the deeper water, above and below the shoals ; but 

 even this dies not appear to have been attempted. 



E.rpeJieney of Improviny. — On the expediency of some improvement there 

 ought not, therefore, as 1 think, to be any difterence of opinion. The ques- 

 tions are, to what extent, in what manner, and how the trade is to be taxed 

 to secure the repayment of the cost of the necessary works V for without good 

 security, either the funds will not be obtained to do what is required, or the 

 terms w ill be unfavourable, for w hich the trade will, in the end have to pay. 

 The idea of paying any thing upon a hitherto tree river may not be more agree- 

 able tlian the payment of tolls ipon turnpike roads ; but if the expenditure 

 be judicious, and the toll equitable, the traveller who pays has the greatest 

 benefit. 



Proposed Depth.— "Mr. Clegram thinks the depth proposed by Mr. Cubitt 

 greater than the vessels that now use the river require : and his observations 

 on the particular nature i f the trade are entitled to great attention. But if 

 is also to be remembered, that the size and draught of a portion, at least, of 

 the \essels, those that load in the river, are limited by the capability of the 

 river; that half the number of Trows go up with half cargoes, caused, I pre- 

 sume, in part at least, through want of water ; and that greater capability 

 would probably give rise to vessels of greater burthen, which at present it 

 would be impnident to construct. Again, the facility of navigating vessels of 

 less draught than the greatest depth, even canal boats, is increased by having 

 a good depth of water. The floods also go off more rapidly; and thus both 

 navigation and drainage are improved. It is to be remarlved, also, that in 

 fixing the level of the lock and weir, which cannot afterwards be increased, 

 Mr. Cubitt is obliged ai once to calculate on his ultimate minimum stimmer 

 depth. Therefore', allliough the depth proposed by Mr. Cubitt may be too 

 much to execute at first, 1 think that nothing particularly below Worcester, 

 ought to be done which will prevent the ileplh he proposes, when there ap- 

 pear occasion and IiukIs for it. The argument, that the upper lock of the 

 Gloucester and Berkeley Canal has only four feet to four feet six inches in 

 times of drought, is good to an extent only, and is a question of inconvenience 

 against expense. A lock of greater size might, 1 presume, be made, should 

 the trade justify such an e.xpenditure. 



Stourport to Worcester, Effect of Weirs. — I also think that, from the in- 

 clination of the river, and the nature of the channel, there is probably no 

 bptler way of improving the navigation between .Stourport and Worcester 

 than by means of lock.s and dams. In saying this, I claim allowance for the 

 limited extent of my information : and certainly, to dispense with the dams 

 altogether, or even partially, would, if practicable, be desirable. Mr. Cleg- 

 ram's idea is that a canal from Worcester to Stourport is practicable, and 

 would be prefeiableto dams. 



Objection to Solid Jl'eirs. — Thus far, and it is a great part of the way, I 

 agree wiih Mr. Cubitt ; but I cannot at all see how, if the dams or weirs are 

 to be .solid, as described, without flood-gates or even waste-boards, neither 

 of which are named, they are not to prejudice the drainage, in place of im- 

 proving it. If made very oblique across the stream, as proposed, their length 

 will no doubt be increased; and with the same depth over the dams, the 

 quantity passed over will be proportioned to the length. But the principal 

 ellect of lengthening the weirs will be to decrease the height of the water 

 running over them, and not so much to increase the cubic quantity ; for the 

 quantity that reaches the weirs, or the depth at the w eirs, is dependent on 

 tlie direct cross-section (the width and depth) and Ihe velocity above the 

 weirs (that is, higher up the river), than where they are pkaced' ; and there 



