TASPORTS has withdrawn its conditional approval for icebreaker Nuyina to sail under the Tasman Bridge to refuel in Hobart.

A non-standard vessel assessment has found the Australian research vessel does not meet the minimum safe criteria to transit the bridge.

TasPorts last year gave Nuyina conditional approval to sail under the Tasman Bridge to refuel at the Selfs Point wharf.

The all-clear followed risk assessments and simulation exercises but was still subject to satisfactory completion of a marine pilot familiarisation and a sea trial program at the Port of Hobart.

Simulation exercises at the Australian Maritime College would also ultimately determine whether the ship could safely transit the bridge.

Tasmanian harbour master Mick Wall said the non-standard vessel assessment was carried out at the request of the Australian Antarctic Division. A collaborative review was undertaken by the office of the harbour master and AAD.

“Ensuring TasPorts’ team of highly qualified and experienced marine pilots were familiar with the bespoke vessel and the way it manoeuvred was pivotal to providing a final assessment for clearance the bridge transit,” Mr Wall said.

“The RSV Nuyina’s non-linear and rounded hull, designed for ice operations, does not have a standard parallel bodied under water area and, as observed on a number of occasions during on-water trials, does not possess the same level of directional stability found in other standard hull form designs when undertaking dynamic turns in windy conditions in confined waters.

“This means that the vessel would exceed the safe minimum clearing distances from the bridge pylons if the RSV Nuyina attempted to transit the bridge.”

Mr Wall said protection of human life, marine assets and the environment were critical considerations for all vessel movements in Tasmanian waters.

Sailing under the Tasman Bridge is a complex operation; important parameters are in place for any vessel that passes under it.

Nuyina was designed and built to fit underneath the bridge to refuel between its voyages to Antarctica.