This post (and my reply below) probably better belong in the “Ghost or Abandoned Lift Bridges over Rivers and Channels” thread here instead, at: http://cs.trains.com/trn/f/111/t/228224.aspx
Nevertheless, I believe the Montrose swing bridge is at these Lat. / Long. coords., just east of the Queen Elizabeth Way:
N 43 2.762’ W 79 7.199’
I believe Bridge 17 - a lift bridge - is at about these coords.: N 42 56.959’ W 79 14.991’
See: http://www.historicbridges.org/bridges/browser/?bridgebrowser=truss/forksrr/
And Bridge 15 - a swing bridge - is at: N 42 58.614’ W 79 15.354’
See: http://en.wikipedia.org/wiki/Welland_Canal,_Bridge_15
and http://www.historicbridges.org/bridges/browser/?bridgebrowser=truss/wellandrr/
See also the photos and maps of the Trillium/ Port Colborne Railway at:
http://www.trilliumrailway.com/pchrmap.php
http://www.trilliumrailway.com/gallery.php
- Paul North.