The line was built with steel sleepers to be termite-proof, and as this resulted in the line being virtually maintenance free ( for the level of traffic involved ), it is the main reason the line has survived, although closure was proposed several times.
22.
The railway line itself, with its use of low level submersible track and bridges and Phillips patented steel sleepers, was an important technical innovation designed for Queensland conditions which has lasted in use with a low level of maintenance for over a hundred years, proving its viability in these conditions.
23.
Steel sleepers were tried as an alternative to timber; Acworth writing in 1889 describes the production of steel sleepers on the London & North Western Railway, and there is an illustration showing rolled channel section ( shallow upturned " U " shapes ) with no shaped ends, and with three-part forged chairs riveted direct.
24.
Steel sleepers were tried as an alternative to timber; Acworth writing in 1889 describes the production of steel sleepers on the London & North Western Railway, and there is an illustration showing rolled channel section ( shallow upturned " U " shapes ) with no shaped ends, and with three-part forged chairs riveted direct.
25.
Track supplies for Phase 3 were also obtained from South Africa and, including some existing stocks, the following were needed : Over 15, 000 ex Donnybrook steel sleepers with rail fastening kits and about of new rail, which was rolled in South Africa to the same pattern as the Donnybrook rail ( 30 kg per metre, in 18 metre lengths ).
26.
Following initial trial tracklaying with the new materials and experience with spring clips recently gained by the Welshpool and Llanfair Light Railway, all Phase 4 track was to be laid in 30 kg / m ( 60 lb / yd ) rail in lengths of 18 m ( 60 ft ) and pressed steel sleepers with specially made 3 mm thick plastic pads between the sleepers and the rails.
