EXCLUSIVE: Multi-million dollar works on 11 rail tunnels from the Toowoomba to Little Liverpool ranges have started, creating 100 jobs over the next 12 months.

State Transport Minister Mark Bailey said the $48 million project would lower the heritage listed tunnels and expand freight potential from the Darling Downs to the Port of Brisbane.

The works will include a scheduled track closure at the end of the month, and will see the tunnels, built in the 1860s, lowered to allow 2.9m high freight shipping containers direct access from the Darling Downs to the Port of Brisbane.

"The first tunnels will be lowered during a major track closure in April," Mr Bailey said.

Toowomba Range Early Works
Toowomba Range Early Works Contributed

"This project has the potential to help reduce the quantity of heavy vehicles required to transport freight on the highway from South West Queensland to the port, improving safety and reducing the impact on our roads.

"This project is a huge vote of confidence in the future growth of agriculture in the Darling Downs and South West Queensland regions which currently produces around a third of Queensland's agricultural output and is a major area for cotton."

InterlinkSQ CEO Michelle Reynolds said the funding and works were catalysts towards a reinvention of the rail freight industry.

"The tunnel upgrade forms an important building block in the future of rail freight," she said.

Works are expected to take 12 months on the nine Toowoomba and two Laidley tunnels, with Queensland Rail to work with BMD Constructions.