Alignment and Track

The erosion control problem has kept railway engineers in the forefront of stabilisation techniques, both in design of earthworks and soil mechanics generally (it is not widely known that Australian consultants finally stabilised the Tazara link in Africa) and in the appreciation of botanical methods of control on desert lines.

From 1900 to 1950, little happened to Australian tracks. True, it was BHP and not foreign mills that rolled the rails, and they grew from 30 and 40 to 53 kg/m. But they were still bolted together by fishplates, still set on hardwood sleepers (usually without sole-plates) and still nailed down by the traditional dogspike fasteners. The only developments were central depot flashbutt welding of 45 ft rail into 360 ft and then 1440 ft strings (N.S.W.) during the Second World War, and the application of elastic spikes and creep anchors. Maintenance remained stoically manual.

Rising costs everywhere and, in the Pilbara region of W.A., unprecedented annual traffic tonnages, led to a complete rail track revolution, much of it based on fundamental research and development of local railway technologies to an extent unprecedented in the Australian railway industry.[12]

The first point of weakness to go was the bolted joint -the major demander of routine maintenance, in favour of aluminothermic field welding. While this was an overseas technology, the welding of head-hardened rail (see below) became an Australian speciality. The next was the dogspike and separate creep anchor, in favour of patented elastic, anti-creep rail fastenings; of four marques widely used here all four are substantially Australian-engineered and made; two are wholly Australian developed, and being applied internationally. Next was the timber sleeper, as supplies of hardwood became scarcer (although modern treatment and anti-split techniques have swung the balance back somewhat) in favour of prestressed concrete and a new generation of steel sleepers. Both these new sleeper technologies were Australian-developed, completely from first principles.

These changes arose not from a piecemeal approach, but increasingly from a 'total track structure' (i.e. systems engineering) approach, based on a proper analysis of track/train dynamics, fundamental research, and application of a 'total systems cost' philosophy to the life cycle cost of the track. The application of the new techniques has extended over all railways, even to the 610 mm gauge sugar cane tramways in Queensland, which cover over 3000 km of track and haul up to 24 Mt of cane in a six month season.

This philosophy included not only the laying and renewal of track, using wholly mechanised methods, but also its monitoring, maintenance and management, in which Australia now leads the world for heavy haul track. Several new technologies were developed for this purpose including computerised monitoring of track geometry (including Australian computer packages to replace overseas developed hardware and software); near continuous optical rail head profile measurement at line speed; positive ultrasonic detection of rail flaws undetectable by earlier overseas techniques; preventive grinding to assure optimum railhead profile and wheel tracking characteristics; and computer driven total management/costing packages (computer controlled on the basis of computerised monitoring, computer controlled tamping, lining and levelling) and computerised identification and management of on-going field research as part of normal operation. The goal is optimal performance of the track system as a whole. In this revolution the Melbourne Research Laboratories of BHP, two high technology companies in W.A. and one in N.S.W., and one track machine manufacturer in Queensland stand pre-eminent. The Bureau of Transport Economics developed a track design package with cost inputs, which has been successfully applied on several railways, and Railways of Australia has two controlled test sections for the scientific study of track structures under operational conditions. The CSIRO and other firms have also played major roles.

Australian Academy of Technological Sciences and Engineering