Mooring Operation On Ships

Mooring operation is one of the important tasks that seafarers have to perform on ship’s deck. Technically,
the operation may seem simple but there are several dangerous associated with it. As a seafarer, you must
have heard about “Death Traps” on ships and how crew members have lost lives during mooring operation.

Working on the ship’s deck is not an easy task. Deck crew has to consider various safety precautions and
understand working of deck machinery and systems, along with cargo operation equipment. When it comes
to mooring operations, additional precautions need to be taken to ensure personal and crew members’
safety.

1. Don’t Allow Any Extra Crew Member on the Deck: Ensure that no extra personnel are present at the
mooring station except those who are involved in the operation. Anyone who is not assisting in the mooring
operation must be asked to leave the mooring station for his/her and other’s safety.

2. Consider Weather Condition: Before planning the mooring operation, consider the weather condition by
taking factors such as wind and current. The ship’s master and responsible officer must have the details of
current and future weather data before commencing the mooring operation.

3. Have knowledge of Snap Back Zone and Rope Bight: All personnel involved with the mooring operation
should be aware of the snap back zones and rope bight.

What makes Mooring Operation dangerous?

There have been several cases reported in the past about accidents during mooring operation that has led to
severe damage or deaths of seafarer.
 The mooring area on a ship comprises of foreword and aft parts of a vessel where winches are installed to
pull the ropes from tug and jetty bollards.

The Mooring area is equipped with several equipment and systems such as winches, hydraulic motors,
bollards, piping valves, anchor chain etc.

Following factors make this mooring area and operation dangerous:

• Use of old and damaged wires and ropes

• Unclear mooring area with unused ropes and equipment

• Mooring ropes are not fastened but stored at winch drum end

• Mooring equipment are not maintained properly

• Undersized and untrained operating staff

• Supervisor of operation is involved with some other work as a result of less crew members

• The painting of mooring area is badly planned with all surfaces and equipment painted with same
colour not highlighting hazardous and tripping sights
• Over painting of drum including corners causing rope damage

• No warning marks painted

• Non slip deck is not available

• Crew not aware of Snap Back Zone

• Crew not aware of dangers of rope bight

• Personal Protective Equipment are not used

• Rope and metal line are joined directly without using thimble which may lead to parting of rope

• Inspection and tests of mooring machineries and ropes are not carried regularly

• Ropes are not arranged on split type drum correctly. The smaller drum must have 4-5 turns and rest
of it should be on larger drum

All the above points are considered by the supervisor i.e. Chief Officer or 2nd officer while preparing a
mooring operation beforehand.
From the above listed points, two important and dangerous phenomena which are responsible for maximum
causalities in mooring of a ship and which are also considered as death traps are-

1) Snap Back Zone:

The highest number of injuries and deaths during a mooring operation on a ship are due to parting of the
rope or wire hitting back to a crew member standing in the area of the rope. The area travelled by the parted
rope having a force enough to kill a person on its way is known as snap back zone.

When ropes are pulled straight then the snap back zone is minimal but if the ropes are turned in bollard or
roller then the snap back area increase. This is shown in the diagram below:

Ship has to be pulled by tugs or by ships own winches for making it close to the jetty for berthing. This
requires strong ropes and wire to be stretched in tension for pulling the ship. Every rope and wire has got its
own endurance limit above which it will fail and part off. The endurance limit will get reduce if the rope is old
or not maintained properly.

The rope will break or part when it is in tension due to pulling action and when these parted rope swings
back in its snap back zone and hits a person standing there, it can be a deadly blow.
The snap back zones in forward part of the ship undergoing mooring operation increases well in number due
to several restrains and turn points with lines in tension as shown in the diagram

The crew performing the operation must be thoroughly trained and qualified with the snap back zone. The
ship fore and aft parts must highlight the snap back zone with signalling paints so that the crew will be aware
not to be on that painted mark when the ropes are under tension.

2) Rope Bight:

Mooring ropes are long and heavy ropes stored on board ships in coil form. When these ropes are under
operation, they tend to form a coil or ring shape naturally known as rope bight.
 If a person involved in mooring operation comes under this rope bight, the pull of the rope can drag him over
the ship or smash him in the hard deck over machines. Several injuries and deaths have been reported due
to crew unaware of standing over bight and dragged by the rope.

The best ways to avoid accidents due to rope bight are:

• Crew must be aware of where he is standing while handling the ropes or when near them.

• Supervisor must concentrate on others action and should not involve himself/herself in the operation
as working hand.

• Inexperienced crew such as cadets and fresh ratings should bellowed to handle rope only under
supervision
• Only required crew should be present on mooring station. It has been commonly seen that those
people who are not involved in the operation (Engine crew or off timers coming on deck) visit the mooring
operation area. Thus, notice should be placed for restricted entry.

• Enough number of deck hands to be present on mooring station to perform the operation smoothly.

should be aware of the snap back zones and rope bight.

4. Check All the Mooring Equipment: Check all the equipment (mooring winch, drums, windlass etc.) involved
in the mooring operation for any kind of problem. Proper routine maintenance is the key to ensure smooth
running of mooring equipment and systems. Don’t forget to check the load sensors of mooring winches.

5. Check the Tail of Mooring Line: If the mooring wire line is provided with tail (short lengths of synthetic fiber
rope which are placed in series with the vessel’s winch-mounted wires to decrease mooring line stiffness and
thus to reduce peak line loads and fatigue due to vessel motions) ensure same size and material of tails are
used for all lines in the same service (breast, spring and head lines). Different tail size and material would
lead to uneven load in the mooring line.

6. Tend One Line at a Time: Only one line should be tended at a time during mooring operation. If this is not
done, it may increase the load in the other tended lines. If two lines are tended together it may lead to
overloading and breakage. Follow the orders of the master or responsible ship officer properly to avoid any
kind of mishap.

7. Keep a Check on the Mooring Line Load: Ensure that the allowable breaking load in any of the mooring
lines does not increase 55% of its Maximum Breaking Load (MBL). This is to prevent the line from breaking.

8. Avoid Mixed Mooring: Mixed mooring is extremely dangerous. Generally, mooring lines of the same size
and material should be used for all leads, if this is not possible due to the available equipment, all lines in the
same service, i.e. breast lines, spring lines, head lines and stern lines should be of the same size and
material. The use of mixed moorings comprising full length synthetic ropes used in conjunction with wire
should be avoided. If a synthetic rope and a wire are used in the same service the wire will carry almost the
entire load while the synthetic rope carries practically none.

9. Keep a Continuous Check: Load on the mooring lines must be checked continuously even after the
mooring operation is over. If there is any change in the ship’s ballast condition, the lines must be slacked or
tightened accordingly. The condition of the rope material should also be checked to foresee unfortunate
accidents.

10. Arrange Mooring Lines Symmetrical: All mooring line must be arranged as symmetrical as possible with
the breast line. The breast line should be perpendicular to the longitudinal centre line of the ship and the
spring line should be parallel to the longitudinal centre line.