Twin Doosan’s make a little tug mighty.

When the Cook Islands Port Authority ordered a new tug, it specified that the boat be just 11m long, have a bollard pull of 10 tonnes and be powered by engines that are simple to operate and maintain.

A pair of Doosan L126TI (M) engines fitted the bill perfectly, and TCC Boats in Picton launched the new tug, Tiu Te Matangi, in February 2022. Matt Byrne, manager of TCC Boats, says the Doosan experience in mechanical engines was essential for the Pacific Island port.

“They didn’t want to deal with electronic technology and plug-in diagnostics, because they don’t have those facilities in Rarotonga,” Byrne says. “The whole idea was to keep it simple, so they can work on the engines with a crescent and a screwdriver.”


The 11m tug is small enough to manoeuvre around the ships in Rarotonga’s narrow harbour and, at 17 tonnes design weight, is light enough to be craned onto the hardstand for annual maintenance.

But in operation mode, the tug takes on an extra 20 tonnes of water ballast, nearly doubling its weight for ship manoeuvres. This increases the tug’s mass to 37 tonnes and deepens its draft to submerge the twin 1250mm diameter propellers. These are on straight shaft drives and built by Diverse Engineering in Nelson, NZ. 

The twin, turbo-charged, 6-cylinder Doosan engines develop 400hp @ 2100rpm, achieving a 10 tonne bollard pull. The M (medium) duty rating suits up to 3000 operation hours per year at up to 70% average load and up to 30% full load.

The Doosan engines of 1060kg each and 11.05-litre displacement allowed a compact installation in the 5.25m beam boat.

TCC are also building a 20.5m cray fishing boat powered by a 1200hp Doosan engine, destined for Invercargill. “The fishermen love Doosan engines because they’re so simple and reliable,” says Byrne.

“Doosan’s quality Korean engineering & design deliver unbeatable value, efficiency and reliability”, says Keith Hogan, Sales Engineer, Marine Products at Lees Group. For these reasons they’ve proved a popular choice for applications like this, including commercial fishing & pleasure craft.  Lees Group have been supplying Doosan engines in New Zealand for more than 10 years. Coupled with D-I Marine Transmissions, these are factory aligned solutions, designed & engineered specifically to work & perform together.


Specification of engines as follows:

Model: L126TI(M) 4-cycle, in-line, direct injection, water-cooled with turbo charger and intercooler

Rating output: 400/2,100

Low idling rpm: 725 +/- 25

No load, max rpm: below 2310

Starting system: electric start by starting motor

Cooling system: indirect sea water cooling with heat exchanger

Direction of revolution: counter clockwise viewed from stern side


For information on Marine solutions in NZ, contact:
Keith Hogan
 | Sales Engineer – Marine Products                                  
LEES GROUP, a division of AB Equipment Ltd

M: +64 27 2131495