Trench widths ?
The LR55 track has been lab tested over trenches 2m wide and shown to be self supporting. Im is normally wider than most utility trenches and allows for a margin of tolerance during site works. 2.6.4 Routines Trenches adjacent to tracks would have to be shored like any other trench in the highway. Then there would have to be safe working practice (eg. lookout). Utilities under a trough ? This would depend on the length. These might be more economically dealt with by digging a parallel trench adjacent to the track and laying a new cable/duct/pipe, unless there is a digless technology eg. removing and replacing the utility in situ. 2.6.5 HMRI Proceedure See 2.6.1 above. 2.6.6 Temporary Track passing loop This was invented in 1894 in Liverpool and is widely used on the Continent. It is temporarily installed like model railway track, and sits in the groove with transition rails to a level about 30mm higher than the original tracks. Trams must make this manoevre at slow speed. It would enab