2011X08 Berthing Damage

 Berthing Damage
- Tasmania.
- Official Report No. 7028.

The Official Report this month contains extracts from an investigation which was carried out by the Marine Investigation Unit of the Australian Department of Transport into the damage caused when the bulk carrier "CHENNAI NERMAI" made heavy contact with a concrete pier in Burnie Harbour, Tasmania. Copies of the report can be obtained from PO BOX 594, CANBERRA ACT 2601. Tel 06 2747324 Fax 06 2746699.

On the approach to the pilotage area, the speed was gradually reduced and at 1942 the engine was test run on "slow astern" for approximately one minute. On the bridge were the Master, Mate, a deck cadet and a helmsman, the Second Engineer was in charge of the engine room. The Pilot boarded at 2000 when the vessel was 1.62 miles north of the breakwater light and the Master advised him that the gyro compass error was 2 degrees low, that the vessel did not have very good stern power and that the draught was 7.5M even keel. The Pilot acknowledged these facts, advised the Master that the vessel would berth stern first at No 5 berth, then ordered "slow ahead" and brought the ship onto the leads (2130). The Mate left the bridge to go to forward stations.
The predicted time of high water was 2012, with a height of 3M above datum, providing a depth of 13M in the turning area inside the harbour breakwater. The Pilot's intention was to swing the vessel to starboard using the forward tug, the transverse effect of the propeller going astern and the effect of the wind on the starboard side of the accommodation block, although he did not discuss these plans with the Master.

At 2011, as the vessel entered the red sector of Round Hill leads, at a distance of 7.75 cables (1426M) off the breakwater, the pilot ordered "dead slow ahead" and altered course to starboard, to bring the ship on to fixed green Port Entry leads. When on the leads (2600), at 2014, he ordered "stop engines". However, the effect of the wind on the starboard quarter caused the vessel to fall off to starboard and at 2015 he had to order "dead slow ahead, wheel hard to port" in order to maintain the correct heading. He ordered "stop engines" again after about half a minute.

The south eastern end of Island Breakwater was abeam to starboard at 2018 when, with the bow entering the lee of the breakwater and the stern still exposed to the full force of the wind, the vessel veered to starboard and the Pilot again had to order "dead slow ahead, wheel hard to port". At 2019 as the vessel passed the tanker berth, the Pilot, bearing in mind the Master's advice about astern power, ordered "full astern", rather than his usual slow or half astern. He expected to have to reduce power to "slow astern" after about 1 minute. At this point the vessel's bow was 440M (just over 2_ ship's lengths) from the dolphin of the bulk berth and 500M from McGaw Pier. A 40 tonnes bollard pull tug was made fast to the port shoulder at this time and the Pilot gave instructions for it to "push full", to commence the swing. The Mate on the forecastle advised the Master that the bow was 300M from the wharf ahead and the Master passed this information to the Pilot, then instructed the Mate to keep him informed of the distance off the wharf.

A 26 tonnes bollard pull tug was made fast on the port side abreast of No 5 hold at 2020, at which time the Mate reported the distance from the wharf ahead as being 100M and decreasing rapidly. The Pilot became concerned at the continued forward speed of the vessel, noting the lack of vibration and transverse effect normally experienced on going full astern on such vessels. He noted the engine revolution indicator was showing 55 rpm astern and at approximately 2020.5 asked the Master for more power but the Master said that the engine was on full astern. The Pilot repeated his instruction to the forward tug to "push full" on the port bow to clear McGaw Pier. He contemplated letting go the anchor but decided against this as he did not wish to stop the bow from swinging to starboard. The second tug, normally only used for pushing vessels alongside at the berth, was lying alongside the vessel, effectively being towed and was not in a position to be able to assist the swing. According to the Master, he had requested the Pilot to ask the forward tug to push on the port bow and had then gone to give a double ring "full astern" but the ship had struck the wharf before he was able to do so.
Conclusions

It is considered that the contact with the Pier, brought about by the ship not stopping and swinging as the Pilot expected, was primarily the result of three factors:

1. The on board practice of manoeuvring the vessel at engine speeds lower than the speeds indicated in the vessel's manoeuvring data.

2. The fact that the Master did not give a double "full astern" to obtain full astern power when the Pilot first asked for more power.

3. The lack of communication between the Master and the Pilot in that:

The Master did not provide the Pilot with a duly completed pilot card and did not explain the on board practice of manoeuvring at lower than listed engine speeds and that "normal full astern" could readily and quickly be achieved by a double ring.

The Pilot did not request a pilot card or seek clarification of the poor astern power and did not discuss port entry, vessel swing and berthing operations with the Master.

It was further considered that:

4. The drag effect of the second tug, towed alongside to port, may have been a contributing factor to the vessel being slow to turn.

5. The underkeel clearance of 5.5M in the turning area was sufficient not to adversely effect manoeuvrability.

6. The encroaching darkness was unlikely to have affected the Pilot's judgement.