Extending the Aratere

In April 2011, Interislander sent its busiest ship, the Aratere on a journey to Singapore for an extreme makeover of epic proportions .The ship was literally cut in half with a new mid-section added to allow it to carry more passengers and freight.

The ambitious project was the equivalent of cutting an eight storey, 150 metre-long building in half, moving the pieces apart, inserting a new piece 30 metre section and joining it all up again.

While undergoing the extension the ship also got a new bow to improve its handling and performance as well as a major internal refurbishment with the creation of new lounge areas.

Extending Aratere – the facts

  • Four months to complete with 800 labourers working around the clock and over a million man-hours expended
  • 30 meter long, 1,500 tonne mid-section added
  • 6,500 pipes and electrical connections cut and then restored
  • Room for 300 more passengers, 28% more rail lane metres and 32% more commercial vehicles.

The timeline

  • 13 April 2011 - Aratere leaves New Zealand
  • 29 April 2011 - Aratere arrives in Singapore
  • 25 May 2011 - Aratere cut in half and two sections are moved apart
  • 4 June 2011 – Prefabricated mid-section inserted and reconnection of sections begins
  • 9 September 2011 Re-Delivery to Interislander and vessel prepares to leave Singapore
  • 23 September 2011 – Aratere arrives back in New Zealand

The Project

Why stretch the ship?

Freight volumes are increasing and we needed more capacity in our fleet, fast.

The quickest and most cost effective way to do this was to extend one of our ships as buying a new ship simply costs more and takes longer to build.

Aratere, the youngest and busiest ship in our fleet was the logical choice for extension.

The red blocks highlighted in the drawing below shows the areas of the ship that would be worked on.

Cutting a ship in two

The extension project was a huge undertaking, from the planning in New Zealand, the work programme in Singapore and the return of the ship to New Zealand.

Once in Singapore the shipyard workers used circular saws for internal small pipework and cables and gas torches to cut the ship at the designed cut line. They cut through everything - the outer hull that was made from steel, the watertight inner hull, cables, pipes and the ventilation system. The cutting process took 12 days.

A large team of workers were involved, at times there were almost a thousand labourers on board, working away in sweltering hot conditions.

Once the cutting was complete the two sections, sitting on lubricated Teflon pads were slowly moved apart by a hydraulic ram.

The new mid-body was inserted into the gap and more than 6,500 pipes and electrical connections were restored.

At the same time new interiors were completed, including the luxury premium plus lounge, children’s play area and food court.

Two new generators were also installed as well as new propellers and a new bow to allow smoother crossings in rougher weather.

Aratere was also fitted with a new 'duck tail' which is a slightly different profile from the old stern. This, plus the new bow and stern help to reduce the ships wake by around 25% which is better for the environment and safety.