The Port of Tauranga is set to receive two new tugs next year after it signed the contracts for the construction of two 70-tonne bollard Rampart tugs.

The first tug will arrive in Tauranga in February next year with the second being delivered in April 2015.

The Port of Tauranga tug Kaimai.

The new tug design.

Both are being built by Cheoy Lee of Hong Kong and have a design life of 25 years.

'They will replace the Kaimai and Te Matua, and greatly enhance the Port's towage capacity and ability to handle the next generation of large ships," says Port of Tauranga Commercial Manager Leonard Sampson.

Operations manager Phil Julian says the whole tug project is worth about $20 million.

It is a departure for the Port of Tauranga, which until now has built all its tugs in Whangarei. The last one was Sir Robert – now 12-years-old.

In part the decision was based on manufacturing capacity but cost is also a factor, says Phil. Much of the componentry is manufactured in bulk in China.

'This is a tug in a series of 70 built already, and that all adds to production,” says Phil.

'These guys specialise. The tug company we are building with has built over 70 tugs – not of that design - but they have a huge amount of experience, knowledge and capability. It's a highly sophisticated tug and these guys are good at building them.”

Cost had a bearing on builder choice says Leonard, but other factors including experience and the amount of exposure Cheoy Lee has on and international basis is also significant, says Leonard.

The tugs have the same configuration as the Sir Robert, with an azmuth stern drive and power delivered through shrouded propeller housings on stalks that can be rotated through 360 degrees, meaning the tug can move in full power in any direction.

It's a style the port is familiar with, and is a highly manoeuvrable and very powerful tug for its 24m size. The new tugs will have a 74 tonne bollard pull, whereas the Sir Robert has a 50 tonne bollard pull.

The new tugs will replace the 20-year-old Voigth Schnieder impellor powered Te Matua and the even older Kaimai, a Schottel driven tug similar to the Sir Robert.

Yet to be decided are the names and the colour. They could be yellow, the same as the pilot boat.

At present the tugs are known as 5077 and 5078.