In the construction of the abutments or piers which support the girders of high bridges and viaducts, cast-iron columns of small size must not be used.
In all large structures a wind-pressure of 56 lbs. per square foot to be assumed for the purpose of calculation, which will be based on the rules laid down in the report, dated 30th May, 1881, of the committee appointed by the Board of Trade to consider the question of wind-pressure on railway structures.
21. The upper surfaces of the wooden platforms of bridges and viaducts to be protected from fire.
22. All castings for use in railway structures to be, where practicable, cast in a similar position to that which they are intended to occupy when fixed.
23. The joints of rails to be secured by means of fish-plates, or by some other equally secure fastening. On main lines, and lines where heavy traffic may be worked at high speed, the chairs not to weigh less than 40 lbs.; but on branch lines, or
lines on which the traffic is light, chairs weighing not less than 30 lbs. may be used.
24. When chairs are used to support the rails they must be secured to the sleepers, at least partially, by iron spikes or bolts. With flat-bottomed rails, when there are no chairs, or with bridge rails, the fastenings at the joints, and at some intermediate places, to consist of fang or other through-bolts; and such rails, on curves with radii of 15 chains or less, to be tied to gauge by iron or steel ties at suitable intervals.
25. In any curve where the radius is 10 chains or less, a check-rail to be provided.
26. Diamond-crossings, as a rule, not to be flatter than 1 in 8.
27. No standing work (other than a passenger platform) to be nearer to the side of the widest carriage in use on the line than 2 feet 4 inches, at any point between the level of 2 feet 6 inches above the rails, and the level of the upper parts of the highest carriage doors. This applies to all arches, abutments, piers, supports, girders, tunnels, bridges, roofs, walls, posts, tanks, signals, fences, and other works, and to all projections at the side of a railway constructed to any gauge.