2.3.1 During the free-fall tests, the boat is
launched from the free-fall certification height a number of times.
The purpose of these tests is to evaluate the strength of the lifeboat
during repeated launches as well its performance and safety under
different load conditions and angles of roll and pitch. The demonstration
of strength for repeated launches from the certification height is
necessary because during its life the boat would be dropped many times
from this height for training and lifeboat drills. It is imperative
that the boat be fully operational and that no major flaws develop
after repeated launches. Also, because the free-fall certification
height is considered a normal operating height, there should be no
damage to items that are primarily non-structural (inner-liners, handrails,
etc.). Ancillary equipment such as compasses and searchlights (and
their mountings) should also remain intact and fully operational.
If the reserve strength test was conducted prior to this test, damage
to structural and non-structural components that may have occurred
during the reserve strength test probably should be repaired to the
original condition. This would provide the best basis for evaluating
the lifeboat during the free-fall tests.
2.3.2 At the judgement of the inspector, some
minor damage may be permitted during the free-fall tests. Regardless,
laminate cracking, delamination, and permanent deformation would usually
not be considered acceptable. The extent of damage, if any, that occurs
can be evaluated in many different ways. A visual inspection should
always be conducted. Permanent deformation is almost always indicative
of serious damage. Depending upon the damage observed, other evaluations
may be required. Ultra-sonic testing and infra-red cameras are non-destructive
methods that can be used to determine the existence and extent of
delamination in FRP lifeboats. At the location of cracks, the lifeboat
could be cored. These cores can be examined to evaluate the depth
of observed cracks and, to a more limited extent, the existence of
delamination. Another way in which possible delamination in FRP boats
can be observed is through the use of unpigmented gel coats when the
lifeboat is manufactured. When such a gel coat is used, the hull or
canopy appears to be cloudy at areas in which delamination has occurred.
Normally the hull and canopy would be translucent when such a gel
coat is used.