English: The founder of the railway, William Pettigrew, was born in Ayrshire, Scotland, in 1825 and came to Moreton Bay in 1849. Although a qualified surveyor, William Pettigrew turned his attention to the timber trade and four years later he built the first steam sawmill on the Brisbane River at William Street, Brisbane.

In October 1872 William Pettigrew travelled to Cooloola Creek where he proceeded to locate a suitable terminus and commenced surveying a railway. By January 1873 construction of the railway had started and this private railway ran from Tin Can Bay inlet about nine miles southwards, tapping valuable Kauri pine forest. In a letter to the Governor, dated 5 August 1873, William Pettigrew and Co detailed the work involved with the development of the railway line from Thannae to Tin Can Bay.

The Mary Ann was the first steam locomotive built in Queensland. It was constructed at the John Walker and Co's Union Foundry in Maryborough. The engine was named after the daughters of William Pettigrew and William Sims who were joint owners of the Pettigrew and Sims Sawmill at Dundathu. The Mary Ann was designed to haul pine logs from the Cooloola forests to Tin Can Bay along the line constructed of wooden rails laid on timber sleepers. The sleepers and rails were milled with a circular saw hauled by the locomotive. On 30 October 1873, after three miles had been constructed, an official opening was held.

A full size replica of the Mary Ann was built as a tourist attraction for the City of Maryborough in 1999 by Wm Olds and Sons Pty Ltd. The replica is operated by volunteers of the Maryborough Whistle Stop Inc on the 3 foot 6 inch gauge Queensland Rail tracks in Queens Park, Maryborough.

Within its collection, Queensland State Archives holds the letter to the Governor from William Pettigrew and Co, dated 5 August 1873, concerning the railway line from Thannae to Tin Can Bay. With the letter William Pettigrew enclosed the photograph of the locomotive engine the Mary Ann.