1841.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



163 



the fourth weir and lock nill be just above Holt Bridge, three miles and three 

 quarters above No. 3 ; and the fifth and last, at Lincomb Hill, four miles and 

 a quarter above No. i, or just forty-one miles from the entrance to the Glou- 

 cester and Berkeley Canal at Gloucester, and one mile and a quarter below 

 Stourport Bridge, making a total distance of forty-two miles and a quarter 

 for the improvement of the river, and making a minimnni navigable rteptli of 

 six feet over the lock sills, without raising the usual summer height of the 

 water in the river at the tails of any of the locks and weirs, or causing any 

 obstruction to the passage of flood waters. 



Such is the mode by which it is proposed to improve the navigation of the 

 river Severn, and which may be more fully understood by a perusal of the 

 plans and sections as deposited with the Clerks of the Peace, in which the 

 details of the measure, as required by the standing orders of Parliament, are 

 clearly and correctly laid down. 



Adverting, however, to a meeting of the land proprietors along the Lower 

 Severn, (viz. from Worcester downwards) held at Tewkesbury, on the IGth 

 December, and a meeting of the parties interested in the navigation of the 

 ■ river Severn, held at Gloucester, in the evening of the same day, at both of 

 which I had the honour of attending, and giving such verbal explanations of 

 this measure as were then and there required ; and with reference also to 

 certain resolutions which were passed at those meetings, and at a sntisequent 

 meeting of the committee of landowners, to the purport generally of requir- 

 ing more definite information in writing from the promoters of this measure, 

 as to the nature and extent of the proposed works, and every particular con- 

 nected witli the undertaking, as regards not only the nature of the works, 

 but also the constitution of the Association for carrjing them into effect, and 

 the amount of tolls to be levied for defraying the cost, and maintaining the 

 undertaking, &e., it may be observed, that there are Some points, perhaps, 

 out of my province to answer. 



In addition, therefore, to what has been explained already with regard to 

 the nature of the works, it may be satisfactory to the parties making inquiries 

 at the meetings above stated to state, 



Istly. That there is no intention of taking land without consent of owners, 

 along or on either side of the river, except at those parts shown on the plan 

 as the situations of the locks and weirs. 



2dly. That the weirs will be solid weirs, placed very obhquely across the 

 river, and of such length that (with the requisite widening of the river at the 

 spot) there will be a greater water way on any cross section of the river at 

 the weir after its erection than before. 



3dly. That the height of the weirs, as shown on the sections, will not raise 

 the water in short-water seasons above the present summer level at the site 

 of each weir next above respectively ; and the depth of water to be maintained 

 by dredging, is a clear six feet below a horizontal line extending up the river 

 from the top of each weir respectively. 



4thly. The locks are proposed to be not less than one hundred feet clear 

 length within the chambers, nor more than twenty feet in clear width, with 

 six feet water over the sills in low summer water. 



5thly, The estimated cost of the works from Gloucester to Stourport is 

 X150,000, of which, as nearly as may be, one moiety will be expended be- 

 tween Gloucester and Worcester, on a distance of between twenty-nine and 

 thirty miles, and the other moiety between Worcester and Stourport, a dis- 

 tance of thirteen miles, or thereabouts. 



6thly. As regards the toUs to be imposed, to meet the above expenditure, 

 maintain the woiks, defray the current charges of management, and (as 

 should be contemplated) raise a fund to pay off the original cost in course of 

 time, — that is probably a question more suited to the committee of manage- 

 ment than the engineer ; the question, however, is in very narrow limits, and 

 assuming the minimum annual amount necessary to be raised for the above 

 purposes, of interest, management, and maintenance, to be £10,000, and 

 which, in my judgment, would be but just sufficient without paying off any 

 capital, it follows that the amount of tolls per ton must depend upon the 

 quantity conveyed along the river both ways, between the three principal 

 points (Gloucester, Stourport, and Worcester) respectively. Taking, there- 

 fore, the charge per ton from Stourport to Gloucester to be double that from 

 Worcester to Gloucester, and assuming the minimum charge for the long 

 length to be sixpence per ton for the whole distance, it will require 270,000 

 tons between Stourport and Gloucester, at sixpence per ton, and 260,000 tons 

 between Worcester and the other two points respectively, at threepence per 

 ton, to raise £10,000. But as various contingencies may arise tending to 

 increase the annual cost, or to diminish the amount of tonnage ; and as a 

 liquidation of the first cost ought never to be lost sight of, 1 strongly recom- 

 mend that powers should be taken to fix a higher toll than sixpence and 

 threepence per ton for the whole and half distances respectively, and am of 

 opinion that one shilling per ton for the whole distance, and sixpence per 

 ton for the Worcester half either way, should be fixed as a maximum, beyond 

 which the commissioners should not have the power to charge, and that six- 

 pence and threepence should be the minimum below which the tolls should 

 not be reduced till such time as the first cost of the works be either funded 

 or paid off; and if provision were made that an additional sum were funded 

 before the tolls be reduced, the interest of which would serve for wear, tear, 

 and management, the river in its improved state might be looked forward to 

 as becoming in time a free navigation. 



"thly. Touching the constitution of the managing body, all I can offer on 

 that head is an opinion many times urged on other parties when attempting 

 to form a company for improving the navigation of the Severn, viz. that the 



improvement of this navigation should be carried into effect by coramis' 

 sioners under an act of ParUament, as a pubhc rather than a private measure, 

 and in sueli manner that the profit or emolument to be derived from the 

 measure, sliould eventually go towards tlie reduction of tolls, and rendering 

 the navigation free instead of being made private gain or individual specu- 

 lation. 



W. CUBITT. 



London, 



Jannari/ 5, 1841. 



Report to the Committee nf Management of tlie Gloucester and Berkeleij Canal, 

 by W. Ciegram, Engineer. 



Gentlemen — In compliance with your instructions, I have carefully ex- 

 amined the plans no v proposed for improving the navigation of the River 

 Severn, from Gloucester to Stourport: and with the explanations which I 

 have received from Mr. Cubitt, the Engineer, by whom tlie works are pro- 

 jected, 1 am enabled to report my opinion upon the subject. 



It is most certain that the interests of the Gloucester and Berkeley Canal 

 Company are deeply involved in the measure — few have more to gain, or 

 m(n'e to lose, from llie success or failure of it, than the Canal Company ; and 

 instead of confining my attention simply to the engineering department, I 

 have endeavoured to take a general view" uf the whole subject, in order to 

 ascertain what are likely to be its effects upon the welfare of the canal. 



To come to a right understanding of the matter, it should be known, what 

 are the existing inconveniences in the navigation of the river, and what would 

 be a sufficient remedy. 



The obstructions to {he free navigation of th.' Severn, arise from two causes, 

 viz. : from too great a quantity of water in time of floods, and from too small 

 a quantity in the summer se son. The firmer is without a remedy. Audit 

 is to supply the deficiency of the latter that the plans of the " Severn Navi- 

 gation Improvement Association," are proposed as a remedy. This deficiency 

 of water is felt on an average, during three months in the year ; and it is the 

 opinion of nearly all the traders on the river, that, if a depth of four feet, or 

 four feet six inches of water could be maintained throughout this period of 

 the year, it would fully meet the wants of the trade. 



To remedy these impediments, and meet these reiiuirements of the trade, 

 the "Severn Navigation Improvement Association" propose to obtain a 

 depth of water in the river, throughout the dry summer weather, of from 

 seven feet, to seven feet six inches between Gloucester and Worcester, and a 

 depth of seven feet between Worcfster and Stourport, by plans so nearly 

 similar to those last proposed, and described in my report of the 12th Decem- 

 ber, 1837, that I need not here recapitulate the particulars, but merely state, 

 that, it is to be eftec'ed by dredging away the shoals in the river between 

 Gloucester and the first dam, w liich is situated just below Upton-upon-Severn, 

 about eighteen miles and a half above Gloucester. This dam will carry the 

 proposed depth to Worcester ; and between Worcester and Stourport there 

 are to be four other dams to give the deptli of water to Stourport. The dams 

 are to be passeil by side cuts and locks. The locks are tu be 100 feet long, 

 20 feet wide, and with six feet of water over their sills. The dams are to be 

 solid, entirely across the river ; but placed so obliquely across the stream as 

 to offer the least possible obstruction to the passage of the flood waters. The 

 entire cost is estimated at 150,000/. Tlie maximum toll is proposed to be 6rf. 

 per ton from Gloucester to Worcester, and 6rf. per ton from Worcester to 

 Stourport; or Is. per ton for the whole distance; to be equally levied upon 

 the goods conveyed by all classes and description of vessels throughout the 

 whole year. And the works, in execution and subsequent management, are 

 to be placed under the control of Public Commissioners. 



This is the plan proposed ; and I cannot say that the opinion I have formerly 

 expressed on the engineering defects of a former and similar plan is in the 

 least degree altered with respect to this — for I consider it, as I did the other, 

 inapplicable to any river similarly constituted with the Severn. Fur from 

 the mountainous rise of the river — its rapidand precipitous course throughout 

 a considerable portion of its length— from the accumulated waters of several 

 rivers being poured into it, and thus being the drain of a very large extent 

 of country. — its waters are not only highly charged with silt held in suspen- 

 sion in them, but vast quantities of gravel and heavy materials are brought 

 down, and rolled over the bed of the river in a continuous stream. Any in- 

 terference therefore (as would be the case by the plan proposed) with the bed 

 of the river, that would destroy its natural powers of cleansing itself, must 

 necessarily entail a heavy and constant expense to provide artificial means to 

 get rid of the accumulations— for with the tidal deposits on the one hand, 

 and the land flood deposits on the other, the accumulations will be very great. 

 I have not documents by me to refer to, but I belie\ e the late celebrated Mr. 

 Telford, when employed about the year 1824 or 1825 to offer some plan for 

 the improvement of the navigation of the Severn, gave a similar opinion to 

 my own. I know that he recommended the formation of a canal between 

 Gloucester and Worcester, at a cost of 200,000/. which he was not likely to 

 have done, had he considered the river capable of economical and permanent 

 improvement. 



But setting aside these engineering difficulties, there can be no doubt that 

 the proposed works are on a much larger scale than is needed. The depth 

 of water over the outer sill of the Gloucester and Berkeley Canal Lock at 

 Gloucester, during the low summer water, beingfrom i feet, to 4 feet Ginches 

 only, is quite the index of what the liepth should be in the river; tor it is 

 clear, that vessels loading in the canal for the river, would not be loaded to 

 a greater depth than that of the water over the sill of the lock through w hich 

 they must pass ; nor would vessels coming down the river at this season 

 (however great the depth of water that might be obtained in the river) be 

 loaded to a greater depth, and thus be subjected to the delay and incon- 

 venience of the transhipment of a part of their cargoes before they could en- 

 ter the canal. As a proof that the trade requires no greater depth than this, 

 I may mention, that it is indeed a rare case for even the largest trows to he 



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