TT-Line and European shipbuilder Flensburger Schiffbau-Gesellschaft (FSG) have signed a letter of intent for the construction of two new ships to replace the current Spirit of Tasmania vessels.
Accommodating 2,000 passengers and crew in 284 cabins and 195 recliners, the vessels will be 212 metres long with 31.5-metre beams.
The 2,519-lane-metre vessels will have a capacity of 1,714 passenger vehicles.
TT-Line chairman Mike Grainger said the companies would begin contract negotiations and agree to final design specifications.
"As previously announced, we expect to place an order for the new vessels in the first half of the 2018 calendar year and for them to be delivered in time to commence operations on Bass Strait in 2021," said Mr Grainger.
