| The safety philosophy
pursued
here is based on the principle of giving
way to natural forces or at least
resisting them as little
as possible. By way of illustration, we compare
the
Eco- Trimaran with a “semi-submerged catamaran or “Small
Waterplane Area Twin Hull” (SWATH),
which reflects an entirely contrary philosophy.
The semi-submerged catamaran (seen
from the
front in the illustration) has two long, streamlined floats which are
each
joined to the main hull by a narrow “neck”. The “neck” spans almost the
entire
length of the float. The amount of buoyancy is calculated
so that the floats remain in deeper water below the waterline, out
of the
reach of waves. This makes the vessel stand “as firm as a rock” even in
rough
seas. Mechanical stress results from the interaction of forces between
the submerged
floats, which act as “fixed points”,
and the main hull, which is
exposed to
environmental forces. The Eco-Trimaran, in |
contrast, offers only
little
resistance to wind and waves. Both can simply flow past it, even
under
the main
hull. The tubular float axles located there are only a minor
obstacle. The
floats hardly protrude above the waterline, so that
breakers are able to roll past them. And since the floaters are
movable, they
are able to adapt to the particular wave and current conditions.
To
answer the question of whether the
Eco-Trimaran’s movable components enhance safety more than detract from
it, it
is helpful by way of comparison to refer to the
suspension of land vehicles. Even though a suspension system requires
additional
engineering effort, it reduces stress on the materials used in the
structure as
a whole and so enhances safety. Or, conversely, without a
suspension system,
the parts of the body supporting loads would have to be designed more
strongly
and more heavily in order to achieve the same level of safety.
|
upward. If the
spaces in
the ship where the pressure
vessels are stored
have vents opening upward which are always open, no hydrogen gas
can collect
inside the hull (refer to the hydrogen safety
report on this
point ).
The following can be said
about the
risk of the pressure vessels
bursting as a result of the high pressure
(700
bar): first, it is planned to distribute storage volume among a number
of
individual tanks. Second, the vessels are to be fitted with a
jacket of
carbon-fibre composite material. This absorbs pressure and, in the
event of
damage, would prevent the metal tank inside from flying apart in
fragments.
Such damage would only shred the fibres and the gas would escape
gradually. This is also important, insofar Hydrogen gas
gets
warm by decompression; this is limited by slowing down decompression
process. |
Engineering 
You are here
Overview
Publishing
information