THE CONTRACT AND PROJECT MANAGEMENT - The Westerschelde Tunnel: Approaching Limits - page 255

Introduction
In June 1996, Minister Jorritsma of the Ministry of Transport, Public
Works and Water Management on behalf of NV Westerschelde T unnel
(public company in the process of formation) and KMW building consor-
tium, signed the contract for both the design and the construction of the
Westerschelde Tunnel as well as the access roads with the correspond-
ing engineering structures. In addition, the contract obliged the contractor
to carry out tunnel maintenance for a period of ten years after it was put
into operation. The contractor also bears the risk of shortcomings and
defects during this period. The completion date of the tunnel was deter-
mined in the contract as 15th November 2002.
The agreement with the building consortium was a so-called design,
build and maintenance contract. The 800 pages of the contract, the result
of a negotiation procedure that was set up right from the first tender in
1992, reflects the extensiveness and complexity in both the technical and
legal sense.
Assumed advantages of the DBM contract
A design, build and maintenance contract (DBM) can have several major
advantages for the client - as was the assumption - compared with the
more traditional methods of putting out to tender:
- the design process is focussed on implementation and because of this,
can result in shortening the implementation period, reducing the loss of
time due to delays and result in effective organization of the engineering
(more efficient way of working);
- the choice of design within a design, build and maintenance contract is
also determined by the possibility of an efficient implementation;
- the design takes into account good accessibility for manpower, equip-
ment and materials (logistics);
- better use of the creativity of the market;
- unambiguous definition of liabilities;
- link between maintenance (M) with design and building (D&B) has the
potential to produce a high quality structure.
A disadvantage compared with more traditional types of contract is, how-
ever, the smaller number of possibilities for the client to influence the con-
struction process. In addition, the pricing is established at an early stage in
the project. As a result, the client has less insight into what such a project
should actually cost.This last disadvantage can, however, be an advantage:
the client knows at an early stage what the price ticket is.
Reason for choosing a DBM contract for the Westerschelde
Tunnel project
A reason for choosing a DBM contract for the construction of the Wester-
schelde Tunnel was the lack of expertise that existed in the Netherlands on
bored tunnels. The building consortium had (and has) this expertise and
therefore it was natural to conclude such a contract. In addition, political
reasons also strongly influenced the choice: the politicians wanted to be