4.4.3 Discarded des ign choices
Several design choices can be discarded before the final
assessment.
Transshipment solution: grab crane
A grab crane requires a high structure and large moving
parts. This creates a very hazardous working environment
for both people and machinery. This method would
also require that a large vessel is moored onto a relatively
small platform, which is actively discouraged by a field
expert (Mammoet Salvage). This method was therefore
discarded.
Transshipment solution: belt conveyor system
This solution was discarded for the same reasons as
those for the grab crane.
Transport problem: push boat
Push boats and barges have been actively discouraged by
a field expert (Mammoet Salvage). These combinations
are just not suited for use on large open waters, due to
the large impact forces that occur between the pusher
and the barge. This solution is therefore discarded for
safety and durability reasons.
4.4.4 Assessment
In this section the best solutions are determined for the
basic functions. First, all of the presented concept solutions
are shown in a morphological scheme (Table 4.12).
After that, promising concepts are set up and assessed
for the applicable criteria.
Since a SWATH vessel platform cannot hold a buffer, it
always requires an external vessel to act as a buffer. Although
the buffer is exchanged when it is full, the transshipment
to the buffer can only be done safely by using a
slurry pump. For each platform type, two possible solutions
can be selected.
The chosen concepts are assessed for each of the remaining
basic functions, which are drawn from the prerequisites.
Not every criterion is used for every assessment,
since they do not always apply. Factors are weighted to
represent the relative importance of the criteria:
• Less important
• Normally important
• Very important
The concepts will receive grades for each criterion, varying
between 1 and 5:
• Bad
• Poor
• Average
• Good
• Excellent
Since all of the solutions share the same transshipment
basic function, no assessment is required for this function.
The only remaining assessment is that of the transport
function, which is shown in Table 4.14