Sure enough, that horn I had heard indeed was another train. Running on the wrong side of the platform, it was a CN (Canadian National) oil tanker train, also running through with out stopping. I was wondering if this was one of the trains I had seen in the large railroad yard at Niagara from the helicopter! Locomotive is CN # 4701 (paired with another whose number I could not note), class EMD GP38-2, Bo-Bo, 2000 hp, built in the early 1980s.(Niagara Falls, Ontario, Canada. Nov. 2015)
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/77742560@N06">shankar s.</a> from Poona (pune), India, India
CC BY 2.0
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/shankaronline/27283466304/">Sure enough, a CN tanker train zips past</a>