1848.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



G9 



tion of Folkestone ia a piece of the legitimate drama ; but the 

 public were truly struck with wonder to hear of tlie production 

 on the shores of the Mersey of a g-reat town, of the most solid 

 construction and of the most magniiicent proportions, pro\ided 

 with all the requisites of a perfect sanitary condition, with its 

 labourers' houses, its park, schools, and market, — and this not a 

 mere city of stone and Roman cement, but jirovided with such vast 

 apparatus for commerce, that the en\y of the London merchants 

 was excited, and Liverpool gave signs how much she feared so 

 great a ri\al near her throne. This, certainly, was a new pheno- 

 menon in England, for though we can add to London in one year 

 a population equal to New York, or enlarge Liverpool with an ad- 

 dition as big as Albany, yet we do not throw our strength into 

 new civic creations. 



Since Birkenhead burst so suddenly on the public gaze the 

 novelty has passed away, — and still more, from fortuitous circum- 

 stances, its glories have been dimmed, and its growth has been 

 cramped ; sr) that the interest it has excited has much worn oft', 

 and we shall be suspected of parading before our readers a stale 

 subject, when we mention Birkenhead ; but as we are not going to 

 describe Morpeth Buildings, nor to investigate the statistics of the 

 trade of the Mersey, nor to recommend the Liverpool merchants 

 to give up and settle at Birkenhead, we may, perhaps, meet with 

 a little attention, for Mr. Webster's book on Birkenhead gives us 

 the opportunity of examining the plan as concerns its hydraulic 

 features. Though Birkenhead may be a gi-eat town, and the 

 docks a great speculation, yet thei-e are scientific considerations 

 involved in the harbour plan, which must render it a matter of 

 permanent interest to professional men. If Birkenhead itself 

 bears experiment, the walling of AVallasey is one of not less im- 

 portance. 



To make a dock is, in the hands of some engineers, a very 

 simple operation ; they scoop out a certain space on the shore, they 

 run out jiiers into the water-way, or take in so much of the 

 strand, and they are satisfied — though, for anything they know or 

 care, the mouth of their docks gets choked up with sand, or the 

 water at the entrance of the harbour is lessened, and a dock made 

 for ships drawing eighteen feet will not take in those of fifteen. 

 They have a great idea of dredging and sluicing power; and 

 besides making a dock or harbour which fails in many of its es- 

 sentials, they burthen it with a permanent establishment for 

 getting rid of the silt which they have let in, and the sand-banks 

 they have created, for it is surprising what very stupid and very 

 careless people can do without knowing it. Mr. Rendel, when he 

 was called in to make a j)lan for VV^allasey Pool, thought it his 

 duty to survey the whole water-way of the Mersey, and to make 

 himself acquainted with the action of the currents and tides, so 

 that, in laying down a deep-water dock at Birkenhead, he might not 

 be shutting the outer gate to seaward — the Victoria Channel. 

 Nothing is more common ;miong seafaring men than to hear them 

 complain, and complain with justice, that in consequence of 

 new engineering «orks in some harbours, the depth of the water 

 in the channel has been reduced, some dangerous shoal extended, 

 some fixed bank made into a quicksand, or a bar which was 

 troublesome enough before made a greater stumbling-block. If 

 there be any up-navigation, that is sure to suft'er when the jioint 

 of discharge into the sea is injured, and the lighterman complains 

 that the channels are dioked, that the tide does not run up so 

 high, or that he has less tide to carry him up ; and the wharfinger 

 finds that his frontage is stopped with sand and shingle. There is 

 "more bungling under the name of hydraulic engineering than 

 j)€rhaps in any branch of the profession. It is the opprobrium of 

 engineering, that after hundreds of thousands have been spent on 

 !Ui hydraulic work, it is a complete failure ; harbours are choked, 

 piers pushed out only to push bars or shingle further seaward, and 

 sea-walls are made with the most solid masonry and with the 

 very smallest modicum of expense or capacity, so that they topple 

 down before the walls are well set. So little is this branch of 

 engineering appreciated by the public, that large tracts of avail- 

 able land — two new shires in fact^ — are left unsecured on the east and 

 west coasts of England, when they ought long since to have been 

 embanked. There is scarcely a river or water-way in the country 

 which is not kept in a state disgraceful to the engineering 

 science of England. Let any one leave the metropolis, and look 

 at the shores of the Thames and Medway : marshes badly drained, 

 or not drained at all ; river walls made so steep that they are 

 yearly cut into or undermined ; and stones put year after year to 

 be washed away, because they are put where they ne\er ought to 

 have been. 



We do not know whether the government ought to take in 

 iiand, as in Holland, the care of our water-ways, for we place no 



confidence in what the government does. The constitution of the 

 Tidal Harbour Commission is not such as to inspire any great 

 hopes from government interference, for while that commission is 

 ornamented with a military engineer in due course, there is not 

 one civil engineer upon it. The one great remedy is by the 

 exertion of the members of the engineering profession to improve 

 the state of hydraulic engineering, and particularly to execute 

 carefully whatever duties they undertake. This, we think, Mr. 

 Rendel has done; and though we differ from him in some points, 

 we have no doubt that he has carefully, conscientiously, and la- 

 boriously exerted himself in this survey for Birkenhead. 



It is tolerably well known that Liverpool is one of the worst 

 harbours in the country, with long and tortuous channels, among 

 dangerous banks, and all the doubts and uncertainties of a bar- 

 harbour, so that its very continuance as a harbour is precarious, 

 and has, before this, been endangered. A\'hile Liverpool is a bad 

 harbour, it is a bad harbour on a large scale ; and those resources 

 of science which are available for the improvement of small har- 

 bours can do very little on miles of sea-channel and acres of sand- 

 bank ; — still they can do a little, and it becomes of great import- 

 ance, that in any operation within the estuary, all care shall be 

 taken to prevent injury to the outer channels. Mr Rendel has 

 tried to improve them. 



The form of the Liverpool estuary is peculiar. It is wide above 

 and nai-row below, so that it has been compared to a bottle with 

 the neck seaward. It is, however, outside the neck of the liottle 

 that the sea-channels and banks are stretched out. Perhai)s we 

 may improve \ipon the bottle simile, by calling the estuary a 

 curved poivder-fiask. Liverpool lies on the neck, on the concave 

 side, and Birkenhead opposite, on the convex side. The wide ])art 

 stretches up to Runcorn. Liverpool formerly had an inlet called 

 the Liver Pool. This has been dammed up, and built upon ; by 

 which so much has been taken from the breakwater. The whole of 

 the docks of Liverpool have likewise been taken from the break- 

 water, being constructed upon the strand. Thus the neck of the 

 bottle has been narrowed \ery much more than it was originally. 



Just above Liver))ool a bank and slielf, called Phickington 

 Bank and Shelf, have been formed, which are not very advantageous 

 to the docks before which they lie. 



The Birkenhead shore has been untouched. It has a large 

 inlet running up, named Wallasey Pool, and this has shown a ten- 

 dency of late years to silt up. Indeed, considering Wallasey 

 Pool, Pluckington Bank, and the general evidence, we should say 

 that tliere is a decided action unfavourable to the good condition 

 of the harbour. 



The deepest water lies on the Birkenhead shore, so that it has 

 a depth below the lowest dock-sills on the Liverpool side. 



It will be seen, that whatever works are undertaken at Birken- 

 head, they may act upon the upper part of the flask, upon the 

 neck and so affect Liverpool outside, and so operate upon 

 the Victoria Bar and Channel. AVhether this action was to be 

 for good or evil very much depended upon Mr. Rendel ; and he 

 might have done as others have done — made his docks, and cared 

 no more about it : but he has w isely taken a wider view, and tried 

 to do all that was possible to improve the state of the harbour. 

 This was done wisely, because the continuance of Birkenhead de- 

 pends upon the good condition of the Victoria Channel ; and if 

 vessels cannot get over the bar outside, they will never be able t^ 

 get into docks either on the Liverpool or Birkenhead side. Mr. 

 Rendel's plan, therefore, is not one merely for making the Birken- 

 head docks ,but lor improving the harbours of Liverpool. 



AVallasey Pool has a wid« mouth, and runs, narrowing as it goes, 

 about two miles inland, taking the drainage of a small district. 

 This Pool is mostly dry at low water. The opening of this Pool is 

 perhaps a mile across. 



This Pool may be taken as two parts, the mouth or funnel, and 

 the upper part. Mr. Rendel's plan is to take advantage of a ledge 

 of rock which runs across the neck, and shut off the upper part bv 

 a great dam with lock-gates, and having a line of sluices as here- 

 after described. 



The upper part constitutes a float of 150 acres, kept up at high- 

 water mark, and on the sides of which docks, wharfs, warehouses, 

 and building-yards may be formed, .'\round this float a river-wall 

 is to be built as frontage to the wharfs. 



The mouth of the Pool is to be embanked, except a low-water 

 basin of 37 acres open to the Mersey. 



The sluices in the dam are to be so arranged as to be near the 

 bottom line of the outer low-water basin, so that on being run out 

 they shall sweep the bottom of it. This they are to do during a 

 part of the tide only, so as to concentrate the action, to keep the 

 basin and its mouth free from silt, and to send the water down to 



