Caption: The Ottawa and New York Railway ran from Ottawa to Cornwall, where a set of railway bridges across the St Lawrence River connected it to the New York Central System.

O & NY was majority-owned and operated by the New York Central Railroad from 1905 through 1957.
Construction of the St. Lawrence Seaway in 1957 required the removal of the Cornwall railway bridges, severing the connection with New York state.
The line was not viable after that.

The data for my negative/positive places this scene of ALCo RS-3 NYC 8262 in Ottawa on 23 September 1952.
Its train consists of a 1912 Russell steam crane with tender, 2 gondolas and caboose.
Crane NYC X126 was 40 years old at the time. Its 10 ton capacity was not for heavy lifting.

Perhaps the location can be identified more precisely; the configuration and quantity of signals suggests a diamond crossing or significant junction.

Information Sources:
Wikipedia article "New York and Ottawa Railway"
https://www.nyc-ottawadivision.com/
https://www.canadasouthern.com/caso/NYC-MODELS-MOFW.htm (NYC crane roster)