Page:Description of the Line and Works of the Sao Paulo Railway in the Empire of Brazil.pdf/7

Rh are of considerable magnitude, most of the excavations being through schistose rock. The line is undulating for the first 12 miles, crossing a succession of short ridges and valleys, with occasional deep cuttings and embankments, after which it follows the course of a valley to São Paulo, with easy gradients and works. The steepest gradient on this section is 1 in 50. The station at the Alto da Serra is unavoidably placed on a curve of 12-chains’ radius, but apart from this the sharpest curve is 20-chains’ radius. There are two iron bridges, each consisting of lattice girders of 40 feet span, supported on cast-iron screw-piles, and four minor bridges from 15 feet to 40 feet span, erected on a similar principle. There are also one hundred and twelve bridges and culverts of substantial masonry, having openings of from 2 feet to 18 feet.

The central station at São Paulo is situated on a level stretch at the summit of inclines of 1 in 60; and ample accommodation for the passenger and goods traffic is provided, with carriage sheds, and workshops for the repairs of the locomotives and rolling stock generally. The head offices of the administration of the Company are situated at São Paulo. Ther eare also two small roadside stations, both provided with sidings, and one with a goods shed, and a small suburban station near São Paulo. All the stations are substantial and neat buildings of brickwork with tile roofs.

From São Paulo to Jundiahy, the present terminus of the line, the distance is 38 miles. Its engineering character is similar to that of the district between the top of the Serra and São Paulo, though the country is more difficult, and the works heavier. After crossing the river Tiété, the main drain of the district, about 7 miles from São Paulo, there is no leading valley to follow, and the railway is, for the most part, carried across a succession of valleys and ridges. The steepest gradient on this section is 1 in 40, for a distance of If mile, and the sharpest curve is 17-chains’ radius. The bridge over the Tiété consists of six openings of 33 feel 4 inches, spanned by lattice girders, supporting cross-plate girders, on which are placed longitudinal balks for carrying the rails. The piers are cast-iron cylinders 2 feet in diameter, sunk to the rock, with a centre pier of masonry on an isolated rock. Another bridge, of three spans of 30 feet, and two single-span bridges of 30 feet and 40 feet, are of a similar construction. There are also one hundred and forty-three culverts, mostly of masonry, and, where practicable, open, with iron or timber girders, and three under road bridges of substantial rubble masonry.

A tunnel, 650 yards in length, was unavoidable at the summit of the gradient of 1 in 40,and a cutting at the northern approach, 30 chains’ in length, which was a source of great trouble. The tunnel for a length of 370 yards is driven through mica schist of a hard and coarse description, with large quantities of quartz, and Rh