Civil Engineering Reference
In-Depth Information
Figure 4.8
Constructing tunnel elements in the approaches. (Courtesy of Kent County
Council/BAM Nuttall/Carillion/Philip Lane.)
DISRUPTION TO NAVIGATION
The impact on the waterway navigation must be considered during early
planning, particularly the operation of dredgers and the associated barge
movements for spoil disposal, and the potential consequences of a sequence
of closures of the waterway to immerse the tunnel elements. Consultation
with the harbor/port authority or coastguard, as appropriate, should be
made early to establish constraints and safeguards that may be necessary
to maintain safe navigation in the vicinity of the tunnel crossing during
construction. In major shipping lanes, this may involve carrying out simu-
lations of ship navigation through the worksite with narrowed or diverted
navigation channels.
Agreement may also be needed for establishing temporary mooring and
berthing facilities and for controlling movements of mutlipurpose vessels or
work barges and the small craft required to service the larger marine plant,
to undertake surveys and support diver operations.
