Page 44 - CHIRP annual digest 2016.pdf

CHIRP Maritime

minimum safe CPA it is incumbent on the other to act
accordingly and to give way if they are the give way vessel,
EVEN IF THEY CONSIDER SUCH A DISTANCE TO BE SAFE
FOR THEM TO STAND ON.

Round turns
Round turns to avoid collision are not specifically
prescribed in the COLREGS in action to avoid to collision.
They may however be effective as an action of last resort.
Caution needs to be taken however. A large vessel making
way ahead with pivot point in a turn forward will always
put her stern closer to the vessel she is turning away from
rather than her bow. Inevitably the CPA will therefore
always therefore be closer than the original ARPA
prediction, especially in all aft vessels where the radar is
mounted on her mainmast as with most vessels. This
manoeuvre always puts the ship’s engine room and her
most vulnerable part closest to the vessel she is turning
hard away from. This is especially so at close range when
the hard over round turn is an action of last resort. The
manoeuvre also reverses the course which may have
implications with vessels astern, such as in a TSS, that may
well be at short and now rapidly closing range. The transfer
distance in a reciprocal course turn will be high and may
therefore impinge in TSS boundaries if applicable. A round
turn is therefore a single last resort decision… It may well
be a sound decision with no other option… However the
decision will always be subsequently scrutinised and the
question ask as to what else could have been done sooner.

We have all done round turns … Our professionalism will
always question what we may have otherwise done
beforehand to avoid having it as the only option left.
Experience tells us when you need to do one it is always
means being closer to another vessel than we would have
ideally wished… However when the circumstances are
suitable, and it is safe to do so for buying valuable time
and distance in a close quarters situation, it can be a
valuable manoeuvre well undertaken.

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