There was an excavation in 2007, and this article has a picture of waht was found, very neat.
http://shubie.chebucto.org/documents/2007_09.pdf
"The purpose of the most recent investigation which took place in late July
and early August was to establish the precise locations of the two tracks of
the marine railway, uncover the upper features of the Turbine Chamber, along
with the remains of the Lock, within which it was constructed and finally, the
dig would uncover the stone-lined Tail Race which carried the water from
the stone Chamber returning it to the stream and subsequently the harbour.
Thanks to Bruce Stewart, lead Archaeologist from Cultural Resource
Management Group and his team of staff ,all of this was accomplished."