TNAG-0770-FCO40-974-Construction-of-underground-railway-system-in-Hong-Kong-1978 — Page 163

5.23

Initial System, by extending the underground box further

westwards. This work, it is considered, can be undertaken

without needing to construct down from the surface again.

Running tunnels would be constructed along the MTR alignment, but to a smaller diameter. The precise dimensions

can only be determined after the design of Light Rail Vehicle

is finalised. It is likely that an internal diameter of

4.6m (compared with MTR's 5.3m adopted by MTRC for the Tsuen Wan Extension) will be sufficient, and will allow

for the inclusion of an emergency sidewalk*.

This width

would allow for the subsequent operation of vehicles up to

2.65m wide.

5.24

The major new design work that is required is for the tunnel approach ramps in Des Voeux Road Central and Hennessy Road. These are illustrated in Figures 13 and 14. In both cases

the arrangement shown allows for subsequent extension of the

tunnel section as part of this initial phase. In Des Voeux Road Central two single track tunnel approach ramps are shown at 5 percent grades on a staggered layout. Other

physical arrangements are also feasible but this layout

provides the best compromise between traffic circulation and

LRT stops. The layout also provides flexibility in the use of Des Voeux Road since the present arrangements could be maintained as the flow is predominantly eastbound or

the street could be made one-way eastbound as far as Jubilee Street and facilities for servicing and pedestrians improved. Between Central and Western Market the tram tracks would be

removed entirely. On completion of the approach tunnel

in the east the LRT route through Johnston Road would be

closed and transferred to Hennessy Road.

*Unlike MTR trains, the Light Rail Vehicle will not have end doors.

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