Bulk carrier grounds after dragging anchor

Lookout! Issue 34, December 2015

A dragging anchor left undetected for several hours resulted in 12 holes in the ballast tanks of a bulk carrier when it grounded on a rocky reef off a west coast port last year.
Bulk carrier vessel
Gerard Pollock ©2019
The bulk carrier that grounded off the west coast last year.

The Master managed to refloat the vessel without assistance but failed to report the grounding, as required by the Maritime Transport Act. He was fined $2000 after pleading guilty to a charge of failing to notify Maritime NZ. No spill of oil was detected but the incident posed a potential threat to the 21 crew, and could have had a serious impact on the environment.

The 177 metre bulk carrier had discharged cargo at Tauranga and Auckland – where a Port State Control inspection found no deficiencies – before rounding Cape Reinga on its way to the west coast. The vessel anchored 2.4 nautical miles, or about 4km, off the port in the late morning, and was scheduled to berth at midnight to unload a further cargo of soya bean pellets.

The starboard anchor was let go with eight shackles, or 220 metres, of cable in the water at a charted depth of 27 metres. The crew plotted the anchor position on the chart and a 370 metres radius safety swinging circle was drawn. New positions were plotted during the afternoon and evening, but the crew did not realise the ship was dragging its anchor in a south easterly direction, and was slowly closing on the coast astern.

At 4pm the chart shows that at the handover from the Second Mate to the Chief Mate the vessel was about 1.5 cables, or 280m, outside the safety swinging circle first plotted.

The crew had plotted the anchor position on the chart, and new positions were plotted during the afternoon, but they still did not realise the ship was dragging its anchor. The weather and sea conditions continued to deteriorate, with gale-force westerlies and swells rising to four metres. By shortly after 6pm, the vessel had edged a kilometer closer to shore from its first position.

The Chief Mate had set the anchor drag alarm soon after 5.30pm, but when the alarm sounded at around 7pm it was subsequently cancelled. A VHF radio call from the local Port Control at around 8pm was the trigger for the Master and crew to finally take action.

The Master arrived on the Bridge at the same time as the call from Port Control was being received. By that stage the vessel was 1400 metres closer to the shore – and was only 1300 metres from danger.

The Master ordered the anchor to be raised and the engine room to start readying to be able to manoeuvre the vessel away from the coast.

The Chief Mate went forward with the Bosun and two crew members to begin heaving the anchor. But in the heavy swell and worsening winds – and without the engine being operational to position the vessel for easy pulling – there was too much weight on the cable.

This resulted in further delay, until the engine was operational and the heaving could begin again at 8.20pm. Ten minutes later the Chief Mate reported four shackles were on deck, but that heaving had stopped because the windlass clutch level and pawl had slipped out of position.

Damage to bulk carrier hull
A hole gouged in the bottom plating of the hull.
Maritime New Zealand ©2019

A temporary fix had to be fashioned, using a chain block, before heaving could recommence a further 30 minutes later, at 9pm. The Master informed the vessel’s owners and charterers of the possible need to request tug assistance, and rang Port Control at 9.05pm to request a tug come to their aid.

With less holding power due to the reduced amount of cable in the water, the bulk carrier continued drifting closer to shore. The Master used the main engine to try and control the vessel while the rest of the cable and anchor was heaved aboard; but by then the wind speed had increased to an average 35 knots from the west, with the vessel rolling heavily in the 4m north-westerly swell.

At 9.22pm the cable and anchor had not been fully recovered and the Master requested a second tug for assistance. Fifteen minutes later the huge anchor was finally off the seabed, and the Master briefed Port Control and cancelled his request for tugs.

However, by this time, the echo sounder showed depths of less than a metre, and at 9.38pm the cargo vessel grounded. Lying port side on a reef, the Chief Mate reported the ship was taking on water in the fore peak tank.

The Master ordered “full ahead” at 9.40pm, but initially no head-way was made. Over the next few minutes the engines slowly managed to pull the 20,000 gross ton vessel off the reef. Once clear, the Master ordered soundings to be taken of all ballast, bilge and fuel tanks.

He took the vessel out to sea to assess the situation and held off berthing until weather conditions improved. Soundings confirmed that seawater had entered the fore peak and number 1 ballast tanks, and later confirmed water had also entered numbers 2 and 3 port ballast tanks. There was no indication that any of the fuel tanks had been breached.

The Master ordered the fore peak tank to be pumped out, and at 10.05pm advised the ship’s agent and Maritime NZ of the anchor dragging. He failed to report that the vessel had grounded and was taking on water. It was not until three days later that the ship’s agent forwarded an incident report of the grounding to Maritime NZ.

The morning after the grounding, manhole covers – the last line of watertight integrity – were removed from the breached tanks and the tanks inspected by the Master, Chief Mate and Bosun; but the ship did not berth until two days later.

At that point, divers examined the hull bottom plating and found fractures and holes in 18 places across six tanks, and the operating lever of the starboard windlass clutch distorted.

A detention notice was issued by Maritime NZ and a decision made to charge the Master under sections 31 and 71 of the Maritime Transport Act 1994.

The Environmental Protection Authority decided to charge the Master and Mate under section 12 and section 338 of the Resource Management Act for damage to the reef resulting from the grounding.

Temporary repairs took about three weeks to complete to the satisfaction of the surveyor, and then the carrier sailed for Singapore to dry-dock for permanent repairs.

LOOKOUT! Points

  • The grounding occurred because a sequence of defences failed: The anchor did not hold; the results of the position monitoring were not comprehended and escalated up the chain of command; and the integrity of the failed windlass caused a further critical delay in remedial action.
  • Anchorages, however sheltered, can become untenable very quickly in sudden bad weather. It is imperative that at the first signs of deteriorating weather the main engine is put on immediate notice and the relevant crew notified.
  • Anchoring equipment is not designed to hold a ship off a fully exposed coast in rough weather. The International Association of Classification Societies advises such equipment is intended for temporary mooring of a vessel within a harbour or sheltered area, and in good holding ground conditions.
  • When at an anchorage, all navigational aids must be used to monitor the vessel’s position and the relative positions of other ships. In additional to electronic navigational aids, shore transit bearings should be used, whenever possible, as a quick means of detecting whether a vessel is dragging anchor.
  • Contrary to the Master’s Standing Orders, the use of visual fixing techniques, in particular the use of transit bearings, was ignored. These could have provided an early warning that the vessel was moving closer to shore.
  • The Standards of Training, Certification and Watchkeeping (STCW) for seafarers provides guidance for the Officer in Charge of the navigational watch at anchor. This includes that a proper lookout must be maintained; the ship’s position should be plotted regularly; and the Master notified, and all necessary preventative measures taken if the ship drags anchor.
  • In this case, GPS positions were recorded in the anchor position logbook every hour on the hour. Radars and Electronic Chart Display and Information System (ECDIS) were both operational and available to the Office on Watch. The anchor position was plotted on the chart at regular intervals, together with the maximum bridge swinging circle which showed the vessel was dragging anchor. However, it was not comprehended and acted on.
  • Neither of the Officers on Watch believed that the vessel was closing on the shore. Instead, they believed the third officer had probably incorrectly plotted the original anchor ‘let go’ position.
  • Alarms for the GPS and Automatic Radar Plotting Aid (ARPA) were not activated, so two of the more important navigational aids were incapable of providing the Officer on Watch with a warning. Although the Chief Mate set the anchor drag alarm on the radar just after 5.30pm, when it activated at 7pm no-one investigated the reason for it sounding.
  • This case underscores the need for the bridge crew to heed warnings; always cross-check sources of information; and escalate causes of concern.
  • Had the Master been called earlier, he would have had more time to develop a contingency plan – to proceed to sea, let out more cable, and/or drop a second anchor; as well as shorten the notice for the main engine.
  • The defective clutch on the starboard windlass shortened further the time the Master had to rectify the situation. This might have been avoided if more weight had been taken off the cable by using of the main engine to change the position of the vessel. Instead, heaving commenced before the main engine was available, and when the cable was leading across the bow. This significantly increased the load on the windlass and probably contributed to its failure.
  • The Master could have called for the assistance of tugs earlier in the evening as a precaution. However, in the prevailing wind and sea conditions, and with the close proximity to navigational dangers, they may not have been effective.
  • Given the seriousness of the situation, the Master could have considered other options to halt the drag. They include letting go the port anchor; or releasing the bitter end of the starboard cable, to allow the vessel to manoeuvre clear.
  • Any maritime accident, or incident such as this, must be reported immediately to Maritime NZ. Within minutes of the grounding the First Mate and Master were aware the vessel’s hull had been breached. The First Mate heard, and felt, air being forced out of the fore peak vent pipe, and reported it to the Bridge. Reporting the incident immediately can greatly reduce the reponse time for Maritime NZ to react to a potential environmental incident.
  • Had the radio call not been made by Port Control there is no evidence that the Officer of the Watch would have identified his vessel was dragging anchor; so there may have been a further delay in preventative action being taken, and a more serious grounding.

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