Starting from 1 Nov 2021, bulk carriers, tankers and container vessels can pass through Torres Strait with a maximum draught up to 12.5 metres, using AMSA’s under keel clearance management (UKCM) system.
ccording to the Australian Maritime Safety Authority, vessel transits of Torres Strait at drafts to 12.50m cannot be guaranteed every day whereas nearly every day there is sufficient tidal rise to allow transit windows for vessels with drafts up to 12.2M.
This was to ensure the minimum under-keel clearance of at least 1 metre between the bottom of the keel and the seabed was maintained.
…said Conrad Adams, AMSA’s Principal Advisor for Coastal Pilotage Operations.
As in the past, vessels may be required to anchor or slow down to await a tidal window that will permit a safe transit. These waiting times can vary depending on weather and sea conditions experience at that time.
Vessels would also be required to proceed at slower speeds to minimise squat and ensure minimum permissible UKCs are maintained.
As a general guide, vessels can transit Torres Strait at 12.20m draft almost every day of the year. There may only be one tidal window available per day for the deeper transit and vessels may be delayed waiting for the next tidal window and therefore suggest vessel operators and Masters engage with the chosen pilotage provider early for passage planning purposes.
For the records, this latest AMSA change follows extensive sea trials conducted since 2018, in collaboration with the UKCM system vendor, OMC International. The goal of the trials was to verify the accuracy of under-keel clearance (UKC) predictions generated by the UKCM system.
The successful trials enabled AMSA to progressively amend the Torres Strait vessel draught regime accordingly.
All vessels with a draught of 9 metres or above must be piloted by an AMSA-licensed coastal pilot, and all pilots must use the AMSA-approved UKCM system to ensure they maintain the minimum under-keel clearance.
Competency in the use of the UKCM system is individually verified by AMSA, prior to allowing pilots to be assigned to such transits.
Operators of vessels with draughts greater than 12.2 metres will need to plan the timing of their transits in close collaboration with coastal pilotage providers.
Depending on conditions, vessel operators may also need to change transit schedules for Torres Strait so the minimum UKC is maintained, in line with legislation.