Definition - What does Rail System mean?
A rail system is essentially a backup system for the purpose of conveying material back and forth from the tunnel face. It is an integral part of a tunneling operation because the speed of a project will depend on the efficiency of a rail system. The quicker material and manpower can be conveyed; the quicker will be the turnaround time for a project.
Depending on the size of the tunnel boring machine (TBM) and the type of construction, rail systems can be of two types: the single track backup system and the double track backup system.
Trenchlesspedia explains Rail System
Single Track Backup Rail System
A single track backup rail system is used for short length, small diameter tunnels or in places where a launching area is restricted. This system is compact and is easy to operate and maintain. This track system can be used with a muck train or with continuous conveyors.
Double Track Backup Rail System
The double track backup rail system is used for the construction of large diameter tunnels where maximum production is paramount for the quicker progress of the project. A California switch can be installed behind the backup system so that empty muck rail cars are ready near the loading point as the other cars are being filled. This optimizes the rate of advance of the TBM and minimizes delay time between trains.