Seamen were left scattering for safety as an out of control container ship threatened to drive into the Port of Tauranga this week.

Kota Lukis close to the Mount Maunganui wharf. Picture and video: Scott Lloyd-Jones.

The Port of Tauranga recommended the evacuation of the salvage tug Resolve Commander and the nearby fishing vessel Adelaide Star on Tuesday when containership Kota Lukis lost power shortly after leaving the Sulphur Point wharf at 8.20am.

The tugs pulling the 50,000tonne containership off the wharf slipped their lines when Kota Lukis' main engine failed. The engine failure meant hydraulic steering was also lost, leaving the unpowered ship heading towards the Mount Maunganui wharf.

Port of Tauranga tug masters and the port company pilot positioned themselves on either side of the ship's bow to try and stop the fully laden ship.

The collision was prevented by the tug pilots turning the ship, which came within 40metres of the wharf, and the pilot ordering the anchor to be dropped.

The main engine was then able to be re-started and the Kota Lukis continued to an anchorage outside the port where the engine controls were inspected and data was taken by a Maritime New Zealand inspector.

Resolve Commander crew member Scott Lloyd-Jones praises the work of the tug masters and says after being alerted by the tug's captain they loosed the lines in case they had to move from the wharf quickly.

'We did it very quickly, in about one minute.”

Port operations manager Phil Julian says main engine failures are not typical, but they do happen on occasion.

'Pilots and tug masters are trained to always consider the possibility of this occurring and to employ contingency planning to minimise the risk. Tug and anchor use are the main contingencies in these situations.

'The grounding of the Hanjin Bombay in June 2010 was caused by an engine failure and this incident has been a major influence on the development of our training program, particularly the use of manned models.”

The log carrier Hanjin Bombay ran aground in Tauranga Harbour on June 21, 2010 and was later floated free without damage.

On October 23, 2011, the 133metre ship Schelde Trader ran aground between North West Rock and North Rock after losing power when departing the Port of Tauranga. She was also saved from serious damage by quick anchoring.

In order to be licensed to handle a ship of Kota Lukis' class, Port of Tauranga pilots must complete a minimum of 840 individual shipping movements.

The training programme also includes full mission computer simulation training and training at an Australian ship model simulator where emergency anchoring is practised.

'Scaled models are used in a scaled pond to simulate actual sized vessels and their manoeuvring characteristics,” says Phil.

'This means that our pilots have the opportunity to practise emergency anchoring procedures and experience how vessels will react in these situations. Port Ash focuses on the use of anchors in much of their training and pilots come away from these courses with a heightened understanding and awareness of anchor use.”

Port of Tauranga tug masters are each involved in up to 1700 shipping movements each year, making them among the most experienced in New Zealand, says Phil.

They are all experience mariners, the majority of them having more than 20 years' experience.

Tug movements are coordinated by the pilot, who deploys them where they will be most effective.

Kota Lukis is 236 metres long and weighs 50,689 deadweight tonnes unladen. She can carry 4253 20foot container units.

The ship is powered by an eight cylinder in-line two-stroke, slow speed, marine diesel burning heavy fuel oil that produces 36,560kw or 49,680bhp. The cylinder bore is 900mm, the stroke 2300mm.

The engine is started by compressed air and the heavy fuel has to be pre-heated by steam before it can be used in the main engine. Steam is generated either by an auxiliary boiler, or by hot exhaust gases from the main engine passing over the tubes of an exhaust gas economiser in the funnel uptakes.

Maritime New Zealand's Steve Rendle says the Kotu Lukis' engine control computer had 'some sort of issue”.

'When the fresh water cooling pump was turned on it sounds like there was a drop of pressure of some kind and in response to that the computer directed the engine to slow, but because it was at dead slow already, it stopped the engine.”

While at anchor they tried to recreate the scenario, but were unable to repeat it, and the ship was allowed to leave. Technicians will be inspecting the ship in Singapore.

The Kota Lukis has since sailed for Port Kelang.