The plan is another piece in the puzzle of finding the lost convict coal mines, which lie buried under Fort Scratchley.

In August this year, research by the University of Newcastle's Coal River Working Party confirmed that the convict coal mines beneath Fort Scratchley in Newcastle were not only the first coal mines in Australia, but were the first coal mines in the southern hemisphere.

Working Party chair Dr Erik Eklund said the plan was originally rediscovered by Doug Lithgow off a microfilm copy in the Mitchell Library in Sydney.

"The original was found in London after an exhaustive search by Rose Mitchell from British National Archives. Now the University's archives rare books and special collections have obtained a high quality digital reproduction," Eklund said.

"This plan represents an important document of Newcastle's European heritage."

Eklund said the map will be passed onto engineering and surveying specialists to use on the planned drilling program, supported by Newcastle City Council and commercial partners Coffey Geosciences and Monteath and Powys.

The original plan was made in July 1804 by Lieutenant Menzies and sent by Governor King to Lord Hobart in England. It shows the drives, headings and crosscuts made at the coal mine at Newcastle.

The document can be viewed at http://www.newcastle.edu.au/coalriver