Tramway track is used on tramways or light rail operations. Grooved rails (or girder rails) are often used in order to make street running feasible. Like standard rail tracks, tram tracks consist of two parallel steel rails.
Tram rails can be placed in several surfaces, such as with standard rails on sleepers like railway tracks, or with grooved rails on concrete sleepers into street surfaces (pavement) for street running. Another environmentally-friendly or ecologically-friendly alternative is to lay tracks into grass turf surfaces; this is known as grassed track (or track in a lawn), first used in Liverpool in 1924.
The first tramways had a rail projecting above the road surface, or a step set into the road, both of which were apt to catch the narrow tyres of horse drawn carriages. The invention by Alphonse Loubat in 1852 of grooved rail enabled tramways to be laid without causing a nuisance to other road users, except unsuspecting cyclists, who could get their wheels caught in the groove.
The grooved girder rail has been the main system of in street tracks, but where new systems or extension are planned the volume of under street utility plant, cables, pipes, ducts and drains means that a concrete raft foundation increases installation costs, since the utilities are inaccessible, and normally need to be relocated. In the years since the first tramway, highway pavement design has progressed around the world. Flexible and rigid pavements are capable of carrying 80 tonne goods vehicles with 15 tonne axle loads at 100 km/h. Using a 19th century tram track system, which destroys a robust pavement and then requires reinstallment, adds costs to tramway track installation and maintenance.
To work with strong highway pavements, the LR55 system was developed, which can be simplified into a “glue” into the road rail. A comprehensive battery of laboratory testing was completed, with up to 80 tonne axle loading, and cyclic testing for 200 million cycles at 25 tonne axle loading.
A test section was installed in Rotherham Bus station in 1993, where some 1 million bus movements a year passed over it. In 30 months it experienced the same heavy road vehicle impacts as 30 years in a typical radial or arterial road. A section of LR55 was installed in the Sheffield Supertramway in March 1996, to replace a section of conventional track that had failed after just one year of operation. This has been maintenance free, shows little sign of wear, and is predicted to last at least 30 years.
Being a mass/spring/mass/spring system, the LR55 offers noise and vibration reduction of some 30 dB. It is also electrically isolated from the ground with a track resistivity of greater than 1000 Ωkm. This means that any stray currents will be in the micro amp range. Finally as a fully sprung track form, the LR55 significantly reduces track corrugations and uneven wear, thereby extending the life of the rails without the need for regular grinding to maintain an acceptable ride quality.
The LR55 track does not need a concrete raft foundation,so under street utilities are still accessible and therefore do not need relocation. The LR55 is also quicker to lay, and can be laid one rail at a time to minimise traffic management problems.
A grooved rail or girder rail is a special rail designed for tramway or railway track in pavement or grassed surfaces (grassed track or track in a lawn). This was invented in 1852 by Alphonse Loubat, a French inventor who developed improvements in tram and rail equipment, and helped develop tram lines in New York City and Paris.