5.1 Functionality
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Statutory Documents - IMO Publications and Documents - Resolutions - Maritime Safety Committee - Resolution MSC.74(69) - Adoption of New and Amended Performance Standards - (Adopted on 12 May 1998) - Annex 2 - Recommendation on Performance Standards for Track Control Systems - 5 Operational requirements - 5.1 Functionality

5.1 Functionality

  5.1.1 Steering modes

A track control system should be able to steer the ship from her position:

  • .1 to a single waypoint; or

  • .2 along a sequence of waypoints.

  5.1.2 Starting requirements

The system should allow the officer of the watch to start track control only if

  • the ship's position,
  • the difference between track course and actual heading,
  • the ship's manoeuvrability,

will result in a safe approach manoeuvre to the track.

  5.1.3 Primary position-fixing system

The primary position-fixing system used for track control should be an electronic position-fixing system (EPFS) approved by the Organization.

  5.1.4 Position monitoring

The ship's position should be continuously monitored by a second independent position source. This monitoring need not be an integral part of the track control system.

  5.1.5 Early course change indication

In the case of track control by a sequence of waypoints, an early course change indication should be given no later than 1 min before the wheel-over line.

  5.1.6 Actual course change and confirmation

  • (1) In the case of track control by a sequence of waypoints, an alarm should be given at the wheel-over line.

  • (2) The system should provide means for the officer of the watch to confirm the course change at wheel-over.

  • (3) With or without the confirmation, the ship should follow automatically the track.

  • (4) If the actual course change alarm is not confirmed by the officer of the watch within 30 s of wheel-over, a back-up navigator alarm should be given.

  5.1.7 Change of waypoints

In the case of track control by a pre-planned sequence of waypoints, it should not be possible to modify the TO-waypoint, the FROM-waypoint and the NEXT-waypoint while in the track control mode without creating a new track and until:

  • .1 the pre-planning of the new track is completed; and

  • .2 the starting requirements (Section 5.1.2) are fulfilled.

  5.1.8 Turn performance

The track control should enable the ship to sail from one leg to another by turns based:

  • .1 on a preset turn radius; or

  • .2 on a radius calculated on the base of a preset rate of turn within the turning capability of the ship.

  5.1.9 Adaptation to steering characteristics

The track control should be capable of manual or automatic adjustment to different steering characteristics of the ship under various weather, speed and loading conditions.

  5.1.10 Permitted tolerance

Means should be incorporated to prevent unnecessary activation of the rudder due to normal yaw or sway motion and statistically scattered position errors.

  5.1.11 Override function

A track control system should be able to accept a signal from the override facilities to terminate track control mode and switch to the override facilities.

  5.1.12 Heading control mode

A track control system may be operated in heading control mode. In this case, the performance standards of heading control systems are to be applied.

  5.1.13 Manual change over from track control to manual steering

  • (1) Change over from track control to manual steering should be possible at any rudder angle.

  • (2) Change over from track control to manual steering should be possible under any conditions, including any failure in the track control system.

  • (3) After change over to manual control, return to automatic control should require operator intervention.

  5.1.14 Manual change over from track control to heading control

  • (1) Any change over from track control to heading control should be possible under all conditions.

  • (2) The heading control system should take over the actual heading as the preset heading.

  • (3) Any switching back to track control should require operator intervention.

  5.1.15 Steering mode indication

Adequate indication should be provided to show which method of steering is in operation.

  5.1.16 Heading monitoring

Heading monitoring should be provided to monitor the actual heading information by independent heading sources. The heading monitor is not required to be an integral part of the track control system.

Parent topic: 5 Operational requirements
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