1 Provoked by the disappearance and loss of a
number of bulk carriers from mid 1970s onwards the international shipping
community has grown increasingly concerned that such ships are particularly
vulnerable to rapid loss. Consequently, IMO has been taking action
over the years to address this problem and to find appropriate solutions.
Among such actions, the Organization has adopted amendments to the
1974 SOLAS Convention, by introducing chapter
XII in 1997 (amended in 2002), and other related provisions
in chapter II-1, and has also amended the Guidelines on the enhanced
programme of inspections during surveys of bulk carriers and oil tankers
(resolution A.744(18)) on several occasions. More recently, a number
of formal safety assessment (FSA) studies on bulk carrier safety have
been carried out. From these studies, the Maritime Safety Committee
of IMO concluded at its seventy-sixth session in December 2002 that
bulk carriers do deserve continued special attention and a number
of measures were approved to address the issues identified, both structural
and operational.
2 Records of bulk carrier losses indicated, in
a large proportion of the cases studied, that ship's masters often
appeared to be unaware of the imminent danger they were in. Many lost
their lives together with the other seafarers on board as a consequence.
Ship losses were frequently so rapid that the ship did not have time
to send a distress signal.
3 The records studied show that in the event of
loss of hull integrity, in many cases, bulk carriers should be evacuated
as quickly as possible. EARLY ASSESSMENT OF THE SITUATION IS THEREFORE
IMPERATIVE, COMBINED WITH ALERTING A MARITIME RESCUE CO-ORDINATION
CENTRE, ALERTING ALL PERSONNEL ONBOARD AND MAKING PREPARATIONS FOR
EVACUATION. This is of particular importance for single skin bulk
carriers which may not be capable of withstanding flooding of any
cargo hold.
4 Companies should consider the following advice
carefully with a view to improving their own precautionary measures
and procedures for emergencies. The advice applies equally to ships
other than bulk carriers when carrying dense cargoes.
5 In most cases in which bulk carriers have been
lost, heavy cargoes such as iron and other dense ores are a common
factor. Ships are also vulnerable when carrying certain break-bulk
cargoes such as steel products. This could include other ship types.
The small volume taken up by the cargo in the ships' holds results
in a large unoccupied space. This provides potential in a flooding
scenario for large volumes of water to rapidly destroy the ship's
residual buoyancy and, in the case of smaller vessels, its stability.
Larger vessels are also highly susceptible to structural failure due
to increases of weights caused by the influx of water.
6 Heavy cargoes place high loads on the structure,
and structural failure is therefore more probable when subjected to
the additional forces associated with flooding.
7 Deterioration of structure through corrosion,
fatigue and damage is identified as a principal factor in the loss
of many bulk carriers. Failing to identify such deterioration may
lead to sudden and unexpected failure. Bulk carrier crews may be unaware
of the vulnerability of these vessel types. The consequential loss
of a ship carrying heavy cargo can be expected to be very rapid, should
a major failure occur.
8 Spaces forward of the collision bulkhead will,
in the event of flooding, significantly affect the trim of the ship
and reduce freeboard at the bow. In extreme weather this further threatens
the ship as green seas come inboard and impact on hatch covers and
other fittings that protect the water or weathertight integrity of
the ship. Shell plating in the region of the bow protects the fore
peak tank and other spaces as do air pipes and ventilators. If any
of them are damaged the ship's ability to resist further escalation
of flooding is compromised.
9 When it occurs or is likely to occur, masters
should quickly assess damage to their ships by being alert to water
ingress and its consequences. The following guidelines are given to
assist them in this assessment.
Unusual motion or attitude
10 If a ship takes on an unusual trim or heel,
or if her motions become changed, breach of the hull envelope should
be suspected immediately:
- Unusual collections of water on decks may be indicating trim or
heel abnormality.
- Sudden changes of heel or trim will indicate flooding or in smaller
ships with lighter cargoes it may indicate cargo shift.
- Jerky lateral motions can be indicative of large scale sloshing
as would be the case if a hold were flooded.
- On smaller ships, slowing of the ship's roll period may indicate
excessive water within the hull - a serious threat to stability. Ships
fitted with GM meters should be able to identify any unexpected changes
in GM.
- Increases of water boarding forward decks may indicate flooding
of a forward compartment. Trim and freeboard changes are notoriously
difficult to assess from an after bridge.
11
Methods of detection
- Hatch covers may be dislodged by pressure and/or sloshing from
within a hold if flooding occurs through side shell or bulkhead.
- Sudden pressurization of compartments adjoining those that are
damaged or flooded will indicate failure of internal subdivision,
most notably bulkheads.
- Spaces may be monitored, either using gauging or bilge/water level
alarms. Forward store spaces can also be monitored audibly using "talkback"
telephones that may be fitted in forward spaces. Anchor impacts and
water in the space can be detected using telephones of the type that
remain active until switched off from the bridge.
- Hull Stress Monitors, where fitted, may be able to detect unexpected
longitudinal hull girder bending. Torsional stresses may also be detected
through differential changes between port and starboard strain gauges.
- Visual monitoring from the bridge using binoculars, where fitted,
by closed circuit television, can give indication of abnormal water
on deck and local damage. However, assessment of trim or freeboard
using this method is difficult.
- Assessment of trim changes can in certain conditions be detected
by noting the level of the horizon, when visible, against a known
reference point on the foremast.
- Draught and trim can be assessed using draught gauges. Changes
are much more discernible using this method than by visual means from
above decks.
Early readiness for evacuation
12 In the event of identifying or even suspecting
that the ship may have sustained damage, ship's personnel should immediately
be called to their emergency stations. A HIGH PRIORITY SHOULD BE PLACED
ON PREPARING EQUIPMENT FOR EVACUATION. Abandonment should however
only be invoked on the spoken orders of the master following assessment
of the risk.
13 Contact with a Maritime Rescue Co-ordination
Centre (MRCC) and/or owners should be made early if the master has
any suspicion that the ship is damaged. An URGENCY signal is justified
and this should be upgraded to DISTRESS if the ship is confirmed as
damaged.
14 Masters should place a strong emphasis on evacuation
training so that donning of protective suits and lifejackets, launching
of survival craft, and operation of EPIRBs and SARTs is a familiar
process to all ships' personnel. Also included should be shutdown
procedures for main and auxiliary machinery, which can, if left running,
hinder launching of survival craft.
15 Masters may wish to investigate any suspected
water ingress more closely but preparations for evacuating the ship
should be made WITHOUT DELAY and concurrent with any investigation.
Remote methods of observation are preferable to sending personnel
onto decks, particularly in bad weather and/or at night. Deck floodlights
should be used if necessary to try and identify abnormalities. Detrimental
effects on watchkeepers' night vision are of secondary importance
in such circumstances.
16 In circumstances deemed justifiable for sending
personnel onto decks that may be frequently awash with green water,
at least two personnel should go to investigate. They should wear
harnesses that attach them to a lifeline and to each other and should
be in constant (radio) communication with the bridge. Each harness
should be provided with two easily operated clips so that wearers
are always attached to the ship's structure, even when passing across
from one lifeline or structural attachment to another. Lifelines on
both sides of the deck should be rigged at all times and progress
along the deck should always be via the lee or sheltered side. When
weather conditions deteriorate is not the time to begin rigging such
measures. Fencing or shipside rails alone should not be
relied upon without attachment by harness.
17 When a loss of hull integrity is known or suspected,
personnel should not be sent onto decks that are being
regularly submerged or deeply awash. In such circumstances the ship
should be regarded as in imminent danger and priority should be given
to preparations for evacuation.
18 In the event of a collision, masters should
call the ship's personnel to emergency stations with a strong emphasis
on preparing to evacuate the ship. This is particularly important
and urgent in cases where a ship is loaded with dense bulk cargofootnote. Older designs of bulk carriers and small
ships with fewer holds are particularly prone to sudden progressive
flooding if the damage occurs abaft any strengthened bulkheads in
the forward part of the ship. This type of damage is more probable
resulting from collisions in dense traffic or overtaking manoeuvres.
19 In the circumstances highlighted above, particular
emphasis has been placed on being ready for early evacuation or abandonment
of the vessel. For ships carrying high-density cargoes this is of
importance while they are at sea. There may however be cases where
abandonment may be the worst option and for bulk carriers as with
other ship types this is most probably true in the event of grounding.
In close proximity to shore, and especially in bad weather, life-saving
craft launched from the ship are unlikely to save the occupants from
the perils of the shoreline and the process of launching the craft
probably carries much greater danger than remaining on board. Again,
early contact with a Maritime Rescue Co-ordination Centre is important
and the master should not hesitate to broadcast an Urgency or Distress
message. When aground and although the ship may be severely damaged
or broken in two, the accommodation blocks in such strandings usually
survive long enough for helicopter evacuation, as organized and co-ordinated
by the Maritime Rescue Co-ordination Centre, when weather conditions
abate.
20 Companies are reminded that the master is the
one who decides on whether or not the ship is to be abandoned. This
guidance is provided to assist the master in making that decision
and is based on the overriding principle that human life is more important
than property.
21 Companies are also reminded that emergency
contingency planning forms an integral part of the International Safety
Management Code required by SOLAS chapter
IX. They should therefore assess the actual risk to their ships
with consideration of the information given in these Guidelines and
provide in their Safety Management System appropriate advice to assist
the master in assessing the action to take in a situation involving
flooding of the ship.