The Belpair square firebox was an easily identified feature of the CNR S2 Class Mikadoes---here's #3529 at Leetown.However there were differences among the S2's especially the addition of the Elesco Feedwater System which gave those locomotives a very different front endĀ appearance.I think the Vanderbilt tender also improved the overall look of these locomotives.
P1410277 (4) by Ed Creechan, on Flickr
P1410277 (4) by Ed Creechan, on Flickr