Inferno at historic Tasmanian railway deemed accidental

A large fire at an historic railway in Tasmania has been deemed an accident as the premier vows to rebuild the tourist attraction.

A blaze broke out at the Don River Railway in Devonport about 4am on Tuesday.

Three warehouses containing carriages and wood working equipment were engulfed in flames, according to the Tasmanian Fire Service.

Police and fire investigators have determined the fire was accidentally lit with the likely cause being restoration works on a carriage within the main workshop.

An online fundraiser set up by a volunteer stated some heritage carriages and a carpenters' shed had been destroyed.

The railway is operated by volunteers and offers trips along the banks of the Don River.

Tasmanian Premier Jeremy Rockliff said he was devastated by the fire and committed to making sure it was back on track as early as possible.

"That is an iconic heritage rail tourism destination and my heart goes out to all the many, many volunteers over decades that have built that beautiful iconic heritage rail," he told reporters on Tuesday.

"We need to of course assess, take stock and then rebuild."