The Works Of Messrs. Schneider And Co.

THE BORCEA AND MORAND BRIDGES. 137 owing to the vibration ; this was only done when the érection was completed. The piers were ereeted in sections, witli the help of a flooring that was raised as the work progresse«!, and in starting from the base. The changes in the scaffold- ing, and the raising of the material, as well as the lifting of the workmen, were effected with the help of a portable steam engine and steam winches. The érection of the superstructure was commenced in September, 1889, and was completed end of April, 1890 ; ii was carried out entirely on the right bank of the Malleco, on the side of the north abutment. A platform 95 metres (311 ft.) in length, in the rear of the abutment, served for the érection ; the abutment masonry work was stopped at 8.100 metres (26 ft. 7 in.) below rail level, in view of the érection of the superstructure. When a length of 90 metres (295 ft.) had been com- pletely riveted, it was pushed along until it overhung by 15 metres (49 ft.), the wall of the north abutment. These operations were carried out without accidents, the most difficult part of the work being to reach the first pier, as it was necessary to place a counterweight in the rear of the superstructure already erected on the platform. Thirty tons of string-pieces belonging to the third spån served for this purpose. The final operation required about 100 men. The flexion of the front end of the superstructure during the launching never exceeded .530 metre (20^ in.) below the roller plane. When it reached each pier, the front end was lifted by 100-ton hydraulic jacks, to enable rollers to be introduced for contimiing the advance. After each launching operation, the rollers were with- drawn and the superstructure was made to rest on pro- visional cast-iron chairs. When the whole length of the superstructure had been launched, it was lowered by .260 metre (10| in.) and made to rest in the final bear- ings; lowering was effected progressively, 40 to 50 milli- métrés (1| in. to 2 in.) at a time, by means of hydraulic jacks. The whole work weighs 1,410 tons, namely, the piers 660 tons and the superstructure 750 tons. The érection was carried out by Chilian workmen, under the super- vision of skilied foremen sent by Messrs. Schneider and Co. Bridge over the Borcea (Figs. 376, 377, and 378, Plate LXXXIII.) — The Borcea is a branch of the Danube ; it is divided into two arms by the Balta island, which consista of a large tract of marshy ground, frequently overflowed, and situated on the Roumanian Railway from Bucharest to Kustendje. This railway will acquire a great extension of traffic, as it forms, in com- bination with the Black Sea maritime service, a second line for the Orient express. The whole of the viaduct constitutes one of the finest works of modem times ; it is of such an importance—it weighs 13,000 tons—that in order to be able to execute it within the period prescribed, it had to be ordered from three large works; Messrs. Schneider and Co., were entrusted with the part over the Borcea; the Fives-Lille Company, with that over the other arm of the Danube, and the CockerilT Company with the Balta Viaduct, which unités the two. This is through- out a cantilever bridge. Messrs. Schneider and Co. supplied the whole of the steel necessary for the viaducts over the arnjs of the Danube (1893-4). The Borcea Viaduct is 418.20 metres (1372 ft.) in its main part, not including the approach viaducts. It is in three spåns, a central one of 140 metres (459 ft. 3 in.) and two shore spans of 139.100 metres (456 ft. in.). The girders are of varions heights, reaching 33.360 metres (109 ft. 6 in.) over the piers ; they are inclined one towards the other, being 9 metres (29 ft. 6 in.) apart at the base and 2.630 metres (8 ft. 7| in.) at the top, from centre to centre of frames, in the section over the piers. This arrangement has the advantage of reducing the importance of the top cross-stays. The framework of the girders is tubular ; the trellis is constituted by diagonals without uprights. The superstructure tie-bars are fixée! direct to the lower girder frames. The top part of the superstruc- ture is strongly braced, in case the train should leave the rails. The foundations were executed with the help of caissons and compressed air. This work was surrounded with great difficulties, as it was necessary to descend to a deptli of 30 metres (99 ft.) ; the air pressure in the chambers was dangerous for the men, and the lieight of the water some- tiines reached 10 metres (33 ft.) above low-water mark. It was, however, carried out without any serions accident. The érection was effected partly by rafting (senii- parabolieal shore-end girders), and in part with the help of a temporary bridge (cantilever girders). The work I of pile-driving was difficult owing to floods and ice, and it was necessary to build especially strong staging. Trucks fitted with stearn winches served to raise the material and to carry the pneumatic riveting machines. The spécification prescribed mechanical riveting on the spot. Notwithstancling the serions impediments of all kinds due to the climate, the action of the river, the absence of skilied workmen, and the importance of the work, combined with the short time given for its execution, the results obtained exceeded those that had been hoped for. The Roumanian engineers may be praised for this gigantic viaduct désignée! by them. Morand Bridge over the Rhône at Lyons (Figs. 379 to 392, Plates LXXXIV., LXXXV., and Figs. 393 to 398). — This bridge was built in 1888-90 at the spot occupied by an old wooden bridge on pile piers, which had been constructed in 1774 by the architect Morand. It consista of three arches of steel throughout and owing to local conditions the arches had to be made unusually Hat. The ribs are very shallow, being .800 metre (311 in.) at the key, and 1 metre (39f in.) at the springing- The width of the bridge between railings is 20 metres (65 ft. 7 in.) ; the road is 11 metres (36 ft. 1 in.) wide, with a pavement each side, of 4.500 metres (14 ft. 9 in.). The