Jökull - 01.12.1969, Page 117

Fig. 7.
Typical
ice formation
with model
stern to wind.
Estimated
ice weight
equivalent to
90 tons.
consequent reduction in the number of stays
and shrouds. Comparison indicated that be-
cause of its lower centre of gravity the loss of
stability in the latter type is approximately
two thirds of that of the conventionally rigg-
ed ship for the same ice accumulation. In the
conclusions of the BSRA report, it is also
emphasized, that while the removal of ice
catching rigging and deck rails will reduce the
rate at which ice will accumulate on the ship,
the same weight of ice will ultimately be de-
posited and thus the same loss in freeboard
will occur if the vessel remains in icing condi-
tions. Accordingly it is stressed that when icing
conditions are encountered the only safe pro-
tection for the ship is to withdraw from these
conditions as quickly as possible.
The results of this British research led to a
general alteration of tlie rigging of Britisli
trawlers. Fig. 5 gives a side view of a typical
British trawler from 1948, and Fig. 8 a side
view of similar size of trawler from 1958 and
later. The freeboard of these trawlers was also
increased, to give the vessels increased form-
stability. It is interesting to note, that when
it was decided to build lk small side-trawlers,
250 GRT, in East-Germany, for Icelandic own-
ers in 1957—58, is was decided to fit these
vessels with a tripod mast this being recont-
rnended by the Icelandic State Director of'
Fig. 8.
Rigging arrange-
ment of a British
trawler from 1958.
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JÖKULL 19. ÁR 113