G.F. 323
機密
CONFIDENTIAL **
NOTE BY THE PUBLIC WORKS
DEPARTMENT
Technical Data
Immersed tube
tunnel
2400 m
ANNEX C
Bored tunnel
3600 m
Length including
approaches Depth of tunnel
Gradient
87 m below P.D.
55 m below P.D.
5%
5%
Carriageway
2 lanes
Estimated Cost
Immersed tube
tunnel (million)
2 lanes
Bored tunnel
(million)
430
Tunnel
Approaches
Contingency 25%
Total
513
45
45
558
475
140
120
698
say 700 million
595
say 600 million
2.
(excluding investigation and
consultant fees and land cost)
The estimated cost of the immersed tube tunnel is based upon the figure given in Wilbur Smith's interim report on Lantau Fixed Crossing adjusted for length, cross-section and difficult sea-bed conditions. In the case of the bored tunnel the cost is estimated on the tender price of Aberdeen Tunnel.
3.
Immersed tube tunnel
The tunnel has to descend to a depth of 55 m below P.D. to clear off the shipping channel in Kap Shui Mun and to climb to +60 m to join Tuen Mun Road. Because of the deep depression at the sea-bed it would be necessary to build the tunnel along the slope of the seabed.
CONFIDENTIAL
/4.
機密