GLASS RAILWAY SLEEPERS.

Hawke's Bay Herald, Volume XXI, Issue 5545, 24 November 1879, Page 3

GLASS RAILWAY SLEEPERS.

A new and somewhat singular material for railway and tramway sleepers has lately been introduced into England, this material being glass toughened by a process discovered by Air Frederick Siemens, of Dresden. The material used by Mr Siemens for his sleepers is glass of the commonest kind moulded to any desired form. The sleepers are being introduced into England by Mr Hamilton Lindsay Bucknall, who has lately laid some of them on the line of the North Metropolitan Tramways at High-street, Stratford. The sleepers in this case aro of exactly the same section as the wooden longitudinal sleepers they have replaced, J namely rectangular, 4 inches wide by 6 ! inches deep, the upper side being moulded |soas to accurately fit the rails. They are laid in lengths of 3 feet, and to avoid the | danger of settlement at the joints, bearing plates, 10 inches by 5 inches by l£ inch, are placed at these points, these I plates being also utilised for effecting the securing of the rails by a fastening which obviates the necessity of moulding any hole in the glass. We may add that samples of the sleepers above mentioned have been tested by Mr Kircaldy, and their average breaking weight when resting on supports 30 inches apart has been found to be about about five tons, this 1 being probably about two-thirds of the resistance which would be afforded by a good pine sleeper of similar dimensions. It must, however, be borne in mind that whereas the timber would become depreciated by use, the glass promises to be practically indestructible by moisture, etc. The cost of the toughened glass is stated to be about the same per ton as that of cast iron, but as its specific gravity is only about one third that of iron, the cost of any article of given dimensions is of course materially less. The material has as yet been too recently introduced, and too little is known of its characteristics to enable any very decided opinion to be formed as to its future capabilities ; but the results of the experiments so far made with th 9 material are certainly of an exceedingly promising character, and the further development of its application will be watched with much interest. — EngineerviQ.