Page 34 - CHIRP annual digest 2016.pdf

CHIRP Maritime

4. COLREGS

and Navigation –Various

Article. 27 It is usually bad practice, when overtaking another ship,
Overtaking to approach her from dead astern, if only because this
may put the overtaker in the other’s ‘blind arc’. Again –
What did the reporters tell us?
The reporter’s ship, a VLCC, sights an overtaking vessel always think: ‘what if I/she had a machinery break -
down?’. A CHIRP Maritime Advisory Board mem ber,
astern at 3 nm closing on an apparent collision course in
open sea. VHF calls elicit no response. The other vessel when reviewing this case, recalled an occasion at sea
when a ship ahead experienced propulsion failure. Our
makes a small alteration to port and eventually passes the
VLCC at a range of 5 cables, having crossed her stern. expert altered course, overtook, slotted in ahead. His
own ship then suffered a mechanical breakdown.
Extracts from the information passed to CHIRP. ‘The In this example it is not impossible that both ships were
(other) vessel was overtaking at a speed of 18.7 knots (own
heading for the same waypoint, or converging on a
ship 11.1 knots) and appeared to be heading directly for my likely point of shipping concentration. If so the over -
own vessel’s accommodation block. At this point, (the other
taker should have been aware of the fact, and doubly
ship) was approximately 3 miles away. Attempts to contact alert. ‘Red-line-itis’ may also have been in play: ‘follow
(the other ship) to ask for their intentions were met with
the planned track regardless’. Likewise dependence on
no response. We engaged hand steering and put the second bridge electronics may have dulled the judgement of
steering motor on in preparation for any required action on
CPA which would have resulted from visual assessment.
our part. (The other ship) was then observed to make a
small course alteration to port, meaning she would pass CHIRP Suggests
close astern. Final CPA was 5 cables, which in open sea is Don’t approach from dead astern when overtaking. Make
both dangerous and unacceptable’. your intentions clear in plenty of time. Avoid introducing
doubt. Allow ample room. What would happen if either
The lessons to be learnt ship experienced a steering or propulsion breakdown? If
A burdened vessel (in terms of the COLREGS) fails to a close quarters situation is the answer, too little room
make her intentions clear, thus introducing doubt into has been allowed. Keep a good lookout all round, includ -
the minds of those on the other bridge. Though the use ing astern, and be aware of blind arcs. Monitor all vessels,
of VHF radio is not generally recommended in collision especially those whose intentions are unclear.
avoidance, the fact that the reporter’s VHF radio com - The above article was published in MFB42
munication call went unanswered would have added
further concern. Such doubt entered the mind of the Article. 28
ship being overtaken that she took steps to be ready for A Crossing Situation – Collision
an emergency manoeuvre.
Avoidance
Safe distance. The overtaking Rule (13) requires the A container vessel reported failure of a give way passenger
overtaking ship to ‘keep out of the way’. Even the ship – on the reporter’s port bow with a closest point of
passing distance (after course alteration) of 5 cables approach (CPA) ‘close’ on the starboard bow – to alter
under standably seems too close to the reporter. This is course to starboard for him when requested. A VHF
often a matter of judgement and experience; a more exchange showed that the passenger ship considered the
objective way to think about it is to visualise what CPA safe. The reporter (having maintained course and
would happen if either ship had a machinery or steering speed) remained concerned, made a 360 degrees turn to
breakdown. Would a close quarters situation be avoided starboard, and continued on his track, passing under the
by virtue of distance? If not, the CPA is too close. stern of the other vessel.

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