416 



THI'] CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



]Decf.meer, 



The removal of tlie weir at the Uroomiolaw Briiige, and the ileepeiiiiig and 

 dearing of the space upwards to Stockwell liridge, containing nearly 1-1 acres, 

 would give much additional tidal water ; thereby increasing the currents not 

 only through tlie liarbour, but also to some extent in every part of the Clyde 

 downwards ; thus aiding and assistijig that scouring force which acts so 

 powerfully in freeing and keeping clear all river estuary channels from hanks 

 and shoals — the great obstacle to navigation. In the improvement of the 

 navigation of tidal rivers, no ex]>cnse or pains should be spared to increase 

 xhis scouring force, arising from that uniform and constant tidal flow and 

 run of currents ascending and descending alternately, and which are so emi- 

 nently distingmshed by their beneficial effects in preserving navigaljle chan- 

 nels, as compared to tliose violent land-floods, which, in many instances, so 

 frequently carry down immense masses of matter, forming shoals, banks, and 

 bars in them, extremely injurious to the navigation, and involving great ex- 

 pense in keeping them clear. 



The removal of the Weir at the Broomielaw Bridge, and the additional 

 receptacle for tidal water between the Bridges, would have a tendency to 

 sweep and scour away all those impurities which are at present discharged 

 into it by the city sewers. The removal of the weir, ami the deepening and 

 clearing away of the channel of the river, would also have the effect of les- 

 sening the miasma which arises from the present condition of the bed of the 

 Clyde between the bridges, and woidd render the atmosphere of that part of 

 the city much more pure and healthy. 



It is noble and praiseworthy to erect hospitals and asylums for the relief 

 of those who may unfortunately be aftlicted with fever ; but how much more 

 advantageous would it be to cut oft' and destroy the sources from which that 

 contagion arises, by the removal of all ottensivc Matter ? In this respect, the 

 attention paid by the Dutch to many of their cities and towns, offers an ex- 

 cellent example to the jieople of other countries. 



At present, the harbour of Glasgow is a receptacle, not only for a large 

 portion of the debris which the Clyde sends down during floods, but it is also 

 a reservoir for almost the whole of the matter discharged by the city sewer- 

 age. The quantity delivered into the present harbour from those two sources 

 is immense. 



The flood of last .\ugust left a deposit on the steps of the upper ferry- 

 stairs, on the south side of the harljour, as follows ; — On the upper step, 

 reached by the flood, a ilepth of 2 inches ; on the descending steps, 2|, 2J, 

 2f, .31-, 4J, and 5 inches. The last step was about 3 feet 4 inches below 

 ordinary liigh water line. It has been alleged, that the River Clyde leaves 

 little or no deposit ; but the above facts prove the fallacy of such a statement. 

 Besides, no experienced observer could have a doubt on this subject, who has 

 seen the extremely <Iiscoloured state of the water of the Clyde during a flood, 

 by the quantity of alluvium held in suspension, and which is deposited in the 

 bed and sides of the Clyde, wherever the tranquillity of the water is not dis- 

 turbed by a current sutlicient to carry it away ; — and it should always be re- 

 collected, that, in the improvement of the navigation of a river, and the 

 widening of a harbour through which it runs, a velocity of 3 inches per second 

 at bottom will work on fine clay ; that C inches per second will lift fine sand ; 

 8 inches per second, sand as coarse as lintseed ; 12 inches per second will 

 sweep along fine gravel ; 24 inches per second, gravel one inch in diameter. 

 These established facts ought to govern the engineer as to the width which 

 should be given to rivers, and to harbours through which rivers flow, so as to 

 regulate the velocity of the water and prevent them from being silted up with 

 alluvial matter, or involve a serious expenditure in keeping them clear by the 

 artificial means of steam-dredging ; therefore, no exertion or expense should 

 be spared to increase the natural force of the scouring power, by the descend- 

 ing currents through river harbours and river navigations. 



It may be observed, that to keep the harbour of Glasgow clear, and suffi- 

 ciently deep for vessels sailing out and in, requires at least the power of two 

 steam-dredges constantly working ; the annual approximate expense of which 

 is as follows : — 



Expense of one dredging-boat per annum, including repair 



of wear and tear, and interest on capital, at . . JE1368 9 4 



Steam-power drawing the punts .... 500 



Discharging the material and carrying it away . . 1200 



Expense of one dredging-vessel . . . ^3068 9 4 



Then, the annual expense of two steam dredging- vessels will he about 

 £6,130 I8.S. M. The area of the wide part of the harbour between Messrs. 

 Todd and Higginbotham's mill, and the Weir at the Broomielaw Bridge, is 

 about twenty-one acres, which requires to be operated on constantly by two 

 steam dredging-vessels ; this is nearly equal to the rate of 300/. per acre of 

 harbour surface per annum. 



Immediately below the Weir, and within the Port, spaces have been cleared 

 and deepened to 10 feet below low-water line, but which have been filled up 

 in the short period of a few months to 2 feet above it ; thus fiUing up a space 

 of 12 feet in height. Looking at the vast expense of keeping the harbour 

 clear — and again, at the great inconvenience to the shipping by a reduced 

 depth of water, arising from shoals and banks being so rapidly formed w ithin 

 it, so extremely detrimental to its free navigation — I am impressed with a 

 more full conviction, that the most active and the most energetic steps should 

 be adopted to diminish those evils as far as practicable. Therefore, the clear- 

 ng away immediately of the Weir at the Broomielaw Bridge, the widening 

 of the mouth of the Harbour, and the deepening of the River up to Stock- 

 well Bridge, would tend partly to remove the evils here stated, because those 



operations would increase the tidal currents through the harbour, and equahse 

 them at its mouth. 



The matter discharged from the city sewers on the north side into the 

 harbour, might be entirely removed by the construction of a large sewer, 

 commencing near the .fail, and running parallel with the river down to below 

 Barcbiy's Slip, where it would enter the Clyde. This sewer would receive 

 the whole of the drainage which at ])rc>ent falls into the harbour from the 

 city of tilasgow on the north, and would consequently free the port from eon- 

 sideralile deposits which are discharged into it. 



The pecuhar construction of the present harbour of Glasgow, with its nar- 

 row entrance, its head barred by a stone weir extending across from side to 

 side, over which the high tide only sometimes rises Ijut a few inches, so that 

 there is scarcely any percejitible tidal current upwards through it during the 

 whole period of flood tide, until the water has reached above the top of the 

 weir at the Broomielaw Bridge ; the water sent up by the tide of flood, as 

 well as the river water descending and falling over the weir into the harbour, 

 remains in a quiescent state, except iluring the times of floods. Thus, the 

 alluvium contained in the descending waters of the river, the silt carried in 

 by the city sewers, and the fine particles of matter held in suspension by the 

 tidal water flowing up — all meet in the harbour of CUasgow — at every tide, 

 forming immense deposits, undisturbed by any tidal current for more than 

 four hours ; which fully accounts for tlie ra])id manner in which the harbom: 

 of Glasgow silts up, and the great ex])ense which is constantly required to 

 keep it clear and open by steam dredging-vessels. But if that part of the 

 river between the Broondelaw Bridge and Stockwell Bridge, were deepened, 

 it would receive the river ilehris before it could reach the harbour, and it 

 could be dredged up there as cheaply as any where else, and without any in- 

 convenience to the shipping. 



What can he compared to a fine navigable river flowing free and unfettered, 

 without lock or dam, through a city, liiyiug open, by its upper reaches, the 

 rich mineral wealth of the interior country to the enterprise and industry of 

 the people ; while, on the other hand, the lower reaches of the river waft the 

 ships to the ocean, that highway to all the regions of the world ! 



It must he manifest to any person who has obsei ved the immense business 

 which is carried on by small craft, on the waters of the Thames at London 

 between the bridges, on the Seine in Paris, and on many other rivers which 

 run through cities and towns, and the clearing away of the weir at the 

 Broomielaw Bridge, and making the river Clyde navigable through the city, 

 would be a work of the greatest public utility, conferring advantages of the 

 most beneficial kind, not only on the shipping interests, but also on the whole 

 population of Glasgow. 



The Govan Railway delivers at the harbour of Glasgow annually from 60 

 to 05,000 tons of coal ; and although this railway will, in my opinion, con- 

 tinue to increase in its traflic, yet I aui confident that the opening of the up- 

 per navigation of the Clyde would be the means of sending down by water 

 considerable quantities of coal and other minerals, &c. to the shipping in the 

 harbour ; and it may be observed, that the descending tidal and river currents 

 — a power which costs nothing — would offer every facility to the transmission 

 of coal and other articles downwards, which could be shipjied at once from 

 the barges or punts into the ships and steamers lying in the harbour, without 

 encumbering and occupying so much of the quays, or wearing the streets by 

 the constant cartage of s\ich vast quantities of coal, which are not only re- 

 quired for exportation, but also for the supply of the numerous steamers on 

 the Clyde, and those plying to the ports of England and Ireland. Coal- 

 lighters, carrying about 100 tons, descend the Mersey, enter the docks of 

 Liverpool, and supply the shipping. The facilities to river navigation which 

 the Clyde offers, from the harbour to a considerable distance above the city, 

 into the coal and iron districts, are extremely inviting for the caiTying on of 

 a similar traflic. 



The space, as already mentioned, between the Stockwell and Broomielaw 

 Bridges, contains an area of nearly 14 acres. The deepening and the con- 

 struction of wharves within it, would be less expensive, and would aflford 

 comparatively more acconmiodation to the small shipping craft, than any 

 other place which could be found anywhere within the vicinity of the harbotu". 

 The expense of the contemplated works will he nearly as follows : — 



Masonry, in wharves and quay-walls, 1350 feet long . .d7,287 11 6 

 Deepening channel, paving, cranes, pauls, &c . . 8,047 17 

 Securing Stockwell Bridge 1,234 11 8 



Total 



.f2G,570 2 



It may be proper to observe, that the deepening between the bridges to 

 two feet below low water line, will not, in my opinion, disturb the foim- 

 dations of the existing quay-walls in the harbour. 



In concluding, it is to be hoped that the space between the Broomielaw 

 and Stockwell Bridges, which is now waste and useless, without a raft of 

 timber, or even a small boat, to adorn its surface, will very soon be covered 

 with numerous classes oT small vessels, presenting a scene of a busy maritime 

 trade neariy in the middle of the city. And now that railways are about to 

 compete with the steam-boat passenger trade, what immense advantages 

 would it confer on the steam navigation of the river, if the weir were re- 

 moved, thereby enabling the steamers sailing to all the lower parts of the 

 Clyde, to arrive and take their departure from between the bridges, or even 

 from the Broomielaw Bridge, which would be so extreu.ely convenient and 

 central to the inhabitants of the city. 



