ISM.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



43!) 



A PILE-CUTTING MACHINE USED IN BELGIUM. 



(With an Engraving, Plate XVII.) 



The method of laying foundations of piers by caissons lias been so 

 well and minutely described by Labelye and Milne, in their account 

 of the building of Westminster and Blackfriars Bridges, and by other 

 writers on the subject, that it would be useless further to advert to the 

 peculiarities, advantages or disadvantages of that system, than is es- 

 sentially necessary to show the utility of the pile-cutting machine, 

 represented in the accompanying engraving, which is copied from 

 the working drawings, through the kindness of our correspondent 

 Mr. Flanagan. 



The failure of some of the piers of Westminster and other bridges 

 built on the caisson principle, has brought it into disrepute with many 

 English engineers, whilst in France and on the continent in general, 

 the cause of these accidents having been ascertained and a remedy 

 applied, caisson foundations are considered as secure and solid as the 

 more expensive and troublesome syslem of founding by coffer-dams; 

 indeed, a French engineer would consider it more difficult to construct 

 such a coffer-dam as that at present round a pier of Westminster 

 bridge, than to make the bridge itself on the caisson principle. The 

 great desideratum in all hydraulic structures especially, is to have a 

 solid and sound foundation; in England this is generally obtained in 

 such rivers as the Thames, by piling the site of the piers, having 

 previously surrounded it by a coffer dam, and cutting off the piles 

 quite level close to the bed of the river, laying on them a platform of 

 timber, and the interstices filled in with rubble stone, upon which the 

 pier is raised. Now this can be effected by using the machine exhibited 

 in the plate, without incurring the great expense of constructing a cof- 

 fer-dam. The piles are driven au refus, or as far as possible, without 

 injury to them, at a distance of about three feet apart; they are then 

 cut off quite level by the pile-cutting machine, and on them the 

 caisson is laid with the greatest facility. 



Every one who has seen the bridges over the Meuse, the Ourthe, 

 the Vesdre, on the railway between Liege and the Prussian frontier, 

 and who is acquainted with the nature of these rivers, will acknow- 

 ledge that if such structures could be raised on this principle at a very 

 slight expense, when compared with those erected by coffer-dams, it 

 may also with advantage be adopted in this country ; and it must be 

 recollected that the failures of works constructed on the caisson prin- 

 ciple, have been caused either by not piling the site of the piers, as 

 at Westminster Bridge, where the action of the stream washed the 

 gravel from under the caisson, or by leaving the piles too long above 

 the bed of the river and placing them too far apart, as at the. bridge 

 of Tours. It is curious that Labelye, in his description of Westmin- 

 ster Bridge, recommends piling under the caissons where the founda- 

 tions are bad, and yet never adopted it, although he even designed a 

 machine for cutting oft" the piles underwater; it is probable that, 

 had he acted according to his recommendation, the settlements which 

 have taken place in the piers would never have occurred. 



It is evident that in the system here recommended of foundations 

 by caissons, it is necessary to have a very perfect pile-cutting ma- 

 chine, particularly in deep rivers. The accompanying drawing re- 

 presents that which has been used in the erecting of Val Beuvit 

 Bridge, and has been used at the Boveni Bridge, now built across 

 the Meuse at Liege ; it has been found to answer its purpose verv 

 well, and may safely be recommended. 



Fig. 1, a transverse section; Fig. 2, the plan; and Fig. 3, a longi- 

 tudinal section; the same letters refer to the same parts in each 

 figure. This machine consists of a horizontal moveable framing of 

 timber A, supported on four wheels C, which move on two longi- 

 tudinal beams D D, parallel to each other; one of these beams is 

 moved as each row of piles is cut off, and is fixed by iron straps to 

 moveable transverse beams E, Fig. 7 ; from this horizontal platform 



No. 76.— Vol. VI.— January, 1841. 



is suspended, by four screws F, passing through " cogged nuts " a, 

 a vertical framing of iron, C ; about half way down this framing at r, 

 is the pivot on which the arm H, of the saw s, moves; g, are guide 

 bars to change the circular motion of the arm H, of the saw s, into a 

 rectilinear motion: g', an iron stay bolt. Round the four "cogged 

 nuts" a, and a cog wheel placed in the centre at C, passes an endless 

 chain e; on motion being given by the winch handled, to the cog- 

 wheel in the centre, by means of the endless chain passing round the 

 " cogged nuts" a, the vertical framing is raised or lowered as it may 

 be required. The small mill-headed screw n, Fig. 2, adjusts the 

 tightness of the endless chain. By this ingenious method the saw is 

 lowered equally to the necessary depth. As the platform is shifted, 

 the bar m, is spiked to the longitudinal beams D; the screw K, turned 

 by a winch handle, and passing through this bar, gives the forward 

 motion to the whole machine. Fig. 4 is an enlarged view of the ho- 

 rizontal iron stay of the framing G, to which is attached a guide fot 

 the handle. Figs. 5 and 6 are a horizontal view and section ot her 

 centre cog-wheel a, with the adjusting screw n, for tightening the 

 chain. Fig. 7 is a plan of the site, showing the piles and stage upon 

 which the machine travels. Fig. 8 is a side view, and Fig. 9 a trans- 

 verse view. The other details may be better seen on the drawings than 

 explained. It may, however, be necessary to describe how the ma- 

 chine is worked. Having erected a framing, such as is shown in 

 Fig. 7, round the site of the pier, and placed the transverse balks L, 

 the longitudinal beams D, are suspended from them by iron straps, 

 and adjusted by screws, and the whole made perfectly level, then the 

 machine is placed close to the first pile of the row to be cut; the bar 

 m, is then spiked to the beams D, and the saw is lowered to the pro- 

 per depth, as previously described, and is worked by two men, one at 

 each side of the handle H; the whole machine is kept constantly ad- 

 vancing, by means of the propelling screw K. It is thus seen that 

 three men are required to work the machine, two at the saw and one 

 at the propelling screw. 



The machine was designed by the celebrated Belgian engineer, M. 

 Simons. Perhaps it may be well to state that M. De Ridder intends 

 to use the caisson syslem of foundations for a bridge projected to 

 cross the Meuse at Antwerp, where it is fully as deep and wide as the 

 Thames at London Bridge. 



ON STOVES. 



Sir — I have been pleased to observe, in your late numbers, two or 

 three letters on the above subject, since I consider it to be one of 

 great importance and interest buth to the profession and the public, 

 and one hitherto but little understood by either. It appears to me, 

 however, that there is yet scope for an unprejudiced writer to render 

 asting service to the cause of practical science, by an accurate and 

 lucid comparison of all the stoves which are daily competing for our 

 preference in such endless and perplexing variety. For I imagine 

 there are few of us who will join your three correspondents in their 

 very summary condemnation of all the new stoves of the last 10 years. 

 It would be strange, indeed, if so much talent and ingenuity as has 

 been directed to the subject during that period had been wholly fruit- 

 less and abortive, and if we really were now in a worse condition than 

 before. But we cannot fall into such an error. We have too lively 

 a recollection of our old " hot air stoves," with their enormous and 

 expensive Ifires, overheating the chimney and scarcely thawing the 

 air at a yard's resistance, choking us with volumes of burnt air, and 

 requiring almost incessant attention, not to be abundantly thankful 

 for our present efficient, economical, and controulable stoves with thei.i 

 steady heat and automaton regularity. We can all of us now afford 

 to warm our staircases, our halls, our offices, our places of worship ; 

 we can be supplied with stoves for rooms of all sizes, from a vestibule 

 to a Chinese museum, and, in fact, nobody now need be cold in doors. 



But still, Sir, we want more information, we require to know the 

 merits and demerits of each individual stove. It will uot do to consult 



CO 



