The following should be born in mind when handling mooring lines/ropes:

1. Be constantly aware of what is happening around you.
2. Never sit on the bulwark or railing while waiting for something to happen.
3. When throwing a heaving line, never stand on the edge of the deck.
4. When waiting to send out a line, never stand on the edge of the deck. Stand amidships if possible.
5. Never stand in the bight of a mooring line.
6. Never stand between a mooring line and the edge of the deck.
7. Never step on or walk over a slack mooring line between a bollard and the lead.
8. Never stand on, walk over or stand astride taut mooring lines.
9. If you do fall in the water, be aware of the propeller(s).
10. If the ship is close to the quay and you fall into the water, get in between the shore fenders.
11. Do not hold onto the crown of a mooring line’s eye (ie the bight of the eye). If you do, there is a possibility that while pulling it over a bollard or bitt your fingers or hand could get jammed between the rope and the bollard. This could cause you a very painful injury or you could lose your hand.
12. If you have to place a second eye of a rope on the bollard/bitt that already has one around it, “dip” it under and through the eye of the first line. This will lessen the risk of the first line being jammed by the second one when letting go.
13. When carrying out the action under sub par l., always make sure that there is plenty of slack available and that the slack is being held by someone at least if it is a heavy line.

Snap-back zone.
Always keep clear of the snap-back zone. This is the area behind and to the side of a bollard which is
a danger area when the ship starts heaving in on a line. The “snap back” occurs when a line is
heaved up beyond its breaking strain and then parts. The shore side end then flies back viciously
and can seriously injure or kill anyone caught by it. Wire ropes are particularly dangerous as they snake backwards unpredictably. A reasonably safe distance from a bollard having a line tightened about it is approximately 10+ metres. A nylon rope parting around 10 metres from the bollard will fly back about 8 metres. Always make sure that the crew are out of the way when working with a head rope or towline. When the lines are taut, a sudden jerk on the line by the winch or the ship surging either forward or aft can cause the line to snake without warning or part. The snaking can also cause injuries to anyone near the line or bollard.

Mooring/berthing lines.
When ships lie alongside they are made fast with three basic sets of lines:

• Head and stern lines. These provide the main means of keeping a vessel in position and alongside. See 1 and 6 in sketch.
• Breast lines. They help to keep the ship securely alongside the berth with an off-shore wind. See 2 and 5 in sketch.
• Springs. Springs prevent the ship from moving forward or aft. See 3 and 4 in sketch.

The forces acting on a ship, which the mooring lines must resist are the following:

1. The wind. The wind will always have the greatest effect on a vessel, particularly when it is blowing against the side of the vessel. This will tend to either blow it bodily off or onto the berth. It will also be greatest if the vessel is light and /or has a high freeboard.
2. Tides. In South Africa the tides will have a relatively small influence on vessels since the tidal range is only 2 metres maximum. As the tide comes in, the ship appears to rise out of the water, thus stretching the lines and increasing the tension on them. This tends to pull the vessel closer to the quay. When the tide ebbs, the reverse happens.
3. Currents. When tying up in a river or other inland waterway connected to the sea, one must bear in mind the rise and fall of the tide must be taken into account. Special precautions must be taken if there is a chance of the river coming down in a flood.
4. Surges from passing ships or bad weather. Surge caused by passing craft will only occur if the craft goes past at too high a speed. This is particularly relevant with large or deep draughted vessels.
5. The change of draught due to loading/discharging cargo. As the vessel loads or discharges cargoes, the draught will either increase or decrease and in so doing will either cause the lines to slacken or become tauter.