lO 



NA TV RE 



[September 24, 1896 



SECTION G. 



mechanical science. 



Opening Address by Sir Douglas Fox, Vice-President 

 Institution of Civil Engineers, President of the 

 Section. 



It is rather over a quarter of a century since the British 

 Association last held its meeting in the hospitaljle city of Liver- 

 pool. The intervening period has been one of unparalleled 

 progress, both generally and locally, in the many branches of 

 knowledge and of practical application covered by Civil and 

 Mechanical Engineering, and therefore rightly coming within 

 the limits for discussion in the important Section of the 

 Association in which we are specially interested. 



During these twenty-five years the railway system of the 

 British Isles, which saw one of its earliest developments in this 

 neighbourhood, has extended from 15,376 miles, at a capital 

 cost of 552,680,000/., to 21,174 iiiiles, at a capital cost of 

 1,001,000,000/. The railway system of the United States has 

 more than trebled in the same period, and now represents a total 

 mileage of 181,082, with a capital cost of 11,565,000,000 dollars. 



The Forth and Brooklyn, amongst bridges, the Severn and 

 St. Gothard, amongst tunnels, the gigantic works for the water- 

 supply of towns, are some of the larger triumphs of the civil 

 engineer ; the substitution of steel for iron for so many purposes, 

 the perfecting of the locomotive, of the marine engine, of 

 hydraulic machinery, of gas and electric plant, those of the 

 mechanical branch of the profession. 



The city of Liverpool and its sister town of Birkenhead have 

 witnessed wonderful changes during the period under review. 

 Great and successful efiorts have been made to improve the 

 "water-gate to the noble estuary, which forms the key to the 

 city's greatness and prosperity ; constant additions have been 

 made to the docks, which are by far the finest and most extensive 

 in the world. The docks on the two sides of the river have been 

 amalgamated into one great trust. In order properly to serve 

 the vast and growing passenger and goods traffic of the port, the 

 great railway companies have expended vast sums on the con- 

 nections with the dock lines and on the provision of station 

 accommodation, and there have been introduced, in order to 

 facilitate intercommunication, the Mersey Railway, crossing 

 under the river, and carrying annually nearly 10 millions of 

 passengers, and the Liverpool Overhead Railway, traversing 

 for six miles the whole line of docks, and already showing a 

 traffic of 75 millions of passengers per annum. A very complete 

 water-side station connected with the landing-stage has been 

 lately opened by the Dock Board in connection with the London 

 and North-Western Railway. In addition to this, the water- 

 supply from Rivington and Vyrnwy has now been made one of 

 the finest in the world. 



The following comparative figures, kindly supplied Ijy Mr. K. 

 Miles Burton, may be of interest : — 



Population of Liverpool 

 Population of Birkenhead ... 



Area of docks, Liverpool, 



about 

 Area of dock.s, Birkenhead, 



about 



Number of steamers using the 



port 

 Average tonnage of six largest 



vessels entering the port ... 2,890 



The following figures show the importance of the local railway 

 traffic : — 



Number of passenger stations 

 within the boroughs 



Number of goods stations ... 



Number of passengers crossing 

 the Mersey in the twelve 

 months (Woodside Ferry) 



Number of passengers crossing 

 the Mersey in the twelve 

 months (Mersey Railway) 



NO. 1404, VOL. 54] 



58 

 50 



7,143,088 



6,976,299 



To the hydraulic engineer there are few rivers of more interest, 

 and presenting more complicated problems, than the Mersey anil 

 its neighbours, the Dee and the Ribble. They all possess vast 

 areas of sand covered at high water, but laid dry as the tide falls, 

 and in each case the maintenance of equilibrium between the 

 silting and scouring forces is of the greatest importance to the 

 welfare of the trading communities upon their banks. The 

 enclosure of portions of the areas of the respective estuaries for 

 the purposes of the reclamation of land, or for railway or canal 

 embankments, may thus have far-reaching effects, diminishing 

 the volume of the tidal flow and reducing the height of tide in 

 the upper reaches of the rivers. Some idea of the magnitude of 

 these considerations may be derived froin the fact that a spring 

 tide in the Mersey brings in through the narrows between 

 Birkenhead and Liverpool 710 millions of cubic yards of water 

 to form a scouring force upon the ebb. The tidal water is- 

 heavily laden with silt, which is deposited in the docks, and, at 

 slack water, upon the sandbanks. The former is removed by 

 dredging, and amounts to some 1,100,000 cubic yards per 

 annum ; the latter is gradually fretted down into the channels 

 and carried out to sea before the ebb. Whilst a considerable 

 portion of the narrows is kept scoured, in some places right 

 down to the sandstone rock, there is a tendency, on the 

 Liverpool side, near the landing-stage, to silt up, a difficulty 

 counteracted, to some extent, by the extensive sluicing 

 arrangements introduced by Mr. George Fosbery Lyster, the 

 engineer of the Mersey Docks and Harbour Board. 



Very extensive and interesting operations hare been carried 

 on by the Board in connection with the bar at the mouth of the 

 river. Dredgers specially designed for the purpose have been 

 employed for some six years, with the result that 15,142,600- 

 tons of sand and other dredged matter have been removed, and 

 the available depth of water at low-water increased from li to- 

 24 feet in a channel 1500 feet in width. 



Those who have made the transatlantic passage in former 

 years can more readily appreciate the very great advantage 

 accruing from this great improvement. 



Formerly vessels arriving off the port on a low tide had to 

 wait for some hours for the water-level to rise sufficiently to 

 enable them to cross the bar ; the result of a large vessel lying 

 outside, rolling in the trough of the sea with her engines stopped, 

 was that not infrequently this proved to be the worst part of the 

 voyage between New York and Liverpool, and passengers who- 

 had escaped the inalady of sea-sickness throughout the voyage 

 were driven to their cabins and berths within three or four hours 

 of landing. 



Owing to the very succe.s.sful dredging operations, ships of 

 largest size can now enter or depart from the Mersey at any 

 state of the tide, and they are also able to run alongside the 

 landing-stage without the intervention of a tender. 



Such vessels as the Teutonic or Alajestic, of nearly 10,000 

 registered tonnage, 566 feet in length, 57 feet wide, and 37 feet 

 deep ; or the still larger vessels, the Campania or Lticaina, of 

 nearly 13,000 tons register, 601 feet in length, 65 feet in width, 

 and 38 feet in depth, can be seen, on mail days, lying along- 

 side. 



Whilst the estuary of the Mersey presents a narrow entrance 

 with a wide internal estuary, the Dee, owing to extensive 

 reclamation of land in the upper reaches, has a wide external 

 estuary leading to an embanked river of very limited width, up 

 which the tide ru.shes with great velocity laden with silt, rising, 

 in some two hours, then, during a short time of slack water, 

 depositing the silt, which is not removed by the ebb-tide, spread 

 over some ten hours, and therefore having comparatively little 

 velocity. In this case, also, the outer estuary shows a great 

 tendency to silt up beyond the reach of any but the highest 

 spring tides. 



The reclamation of the Ribble has not yet proceeded so far as 

 to so seriously affect the general conditions of the estuary ; but 

 here, also, there is a constant tendency in the channels to shift, 

 and the erosion which takes place when a high tide and wind 

 combine is very remarkable. 



A most important improvement was introduced in 1S86, by 

 Mr. G. F. ]^yster, when it was decided to raise the water-level 

 in certain of the docks by pumping, the wharves being height- 

 ened in proportion, and half-tide basins, or locks, made use of 

 to compensate for the difference of level. 



The area of the docks so treated in Liverpool is 78 acres, 

 whil.st at Birkenhead the whole area of the docks on that side 

 of the river, amounting to 160 acres, is so raised. 



