Engineering Wonders of the World
Volume I

Fig- 1-—A SIGNAL GANTRY BRIDGE AT CREWE SOUTH JUNCTION. THIS METHOD OF MOUNTING SIGNALS SAVES A CONSIDERABLE AMOUNT OF SPACE AND PREVENTS CONFUSION. RAILWAY SIGNALLING. BY H. RAYNAR WILSON. Extraordinary ingenuity has been expended on systems and apparatus for the protection of life and property on railways. In this article some of the most striking inventions for controlling signals and points are passed under review. The diagrams, most of which have been drawn specially, will enable the reader to gain a clear conception of the principles of the apparatus described. IN no branch of railway work has there been such development as in signalling. In 1837 a ball signal was used on the Great Western Railway, which, when at the top of the mast, indicated that the line was clear. The absence of the Early Signals. , „ . . ball signified danger. At night a stable lantern was hooked on to the ball. Later—in 1843—this crude effort gave place to cross-bar and disc signals. The “ danger ” indication was given by the cross-bar, which was 8 feet long and 1 foot deep, being pre- sented to the driver, and “ clear ” by the signal being turned a quarter of a circle, and by the disc, which was 4 feet in diameter and at right angles to the cross-bar, being shown. About this time Sir (then Mr.) Charles Hutton Gregory was resident engineer on the London and Croydon Railway from Rother- hithe, on the London and Greenwich Railway, to Norwood. The idea occurred to him of conveying instructions to enginemen by means (1,408) 15 VOL. II.