OCIMF_Mooring_Equipment_Guidelines_(Second_Edition)

1.7.4 Inslrumented Mooring Hooks or Visual Inspec/ion oJ Mooring Lines

The terminal should monitor [he ship's line tending activity by visual illspectioo of the mooring lines.
particularly during cargo Irao fer and periods of changing environmentaJ conditions.

In addirion to the above. and dependent on the physical environment at the berth. it may be desirable
[0 in tall mooring line load measurement apparatus where an apPTopriate need has been identified.
This equipment is now available and ha.s been installed at a number of large tanker berths and at
many LNG berths. It measures the line loads and has a central read-oUl in the terminal operation's
contIol rOOm. Should the line load become high or the lines become slack. the termina l operator can
advise tJle ship accordingly.

In many terminals mooring tension information is transmitted to a shipboard fixed or portable

display for direct acces by ships staff. In any case tbe termjnaJ should i_ns pect lines periodically. If

poor line tending by ships staff is ob ervcd. the terminal should notify [he ship.

1.8 SHIP MOORING MANAGEMENT

Good ship mooring management requires a knowledge of good mooring principles. information about

the mooring equipment i[lstalled on the ship, proper mai_ntenance of tbis equipment, and good,

seamanlike line tending.

Officers i.D charge of IiJ1C tending and personnel assigned to tend line· should be aware of the

capabilities of the equipment. in ta iled OIl their ship. Specifications should be available on the winch

drum to show the design holding capacity and the torque required on the hand wheel or lever to

achie e tbi _ S pecification of th e mooring lines should also be available.

Recommendation" concerning the proper direction of reeling of the wire on the drum should be

followed and the drum should be marked accordingly to prevent any possibility of error.

1.8.1 Line Tending

The object.ive of good line tending is to ensure that all lines share the load to the maximum extent

possible and to limit (he ship's movement off tbe benh or alongside tbe berth. Pretensioning of lines

(Ihat is loading a line with a winch prior to the application of eJ1virol1lllenlaJ forces) reduces ship

movement and improves the load distribution when lines of different lengths and elaslicilies arc being

used. Figure 1.1.1 demonstrates how prctensioning affects the load distribution and the movement of

the ship.

It is very important to tend spring lines differently from breast Lines. Tending head or stern lines

presents a special problem (which is one more reason why they are not recommended). They must

be tended Ijke eitller spring or breast line depending on whether longitudinal or tIansverse restraint

is more critical. For example, if a high 10ngitudinaJ current on the bow is expecled, the bow Hne

should be pretensiooed while the stem line j tensioned only 10 take up any slack. The following

general ruJes apply to line-lendins.

• Slack line, should be bauled i1l firsl. Slack lin.es may permit excessive movement of the ship
  when there is a sudden change in the environment.


• Only one line should be tended at a time. Any time a line is tended. ;t temporarily changes
  the load in other lines and may increase il. The simultaneous tending of two lines may therefore
  give erratic results or evco an overload.


• Whenever a spring Line is tended, the opposit.e spring must also be tended. Otherwise, rendering
  or heaving·in on one spring line may cause excessive movement of the moored ship along the
  pier face.