Comments on: A perfectly matched quartet of London-built F7’s lead by Wabash 725 clatters across the Dunnville Subdivision diamond at CN Canfield Jct. in May 1964. Doug is standing on the Dunnville Sub – Cayuga Sub. connecting track as 725-659-670 and a 4th engine take a patented Wabash Redball freight west, to St. Thomas and eventually the ferry connection at Windsor. A few years earlier the subdivision speed limit was 60mph for freight and judging by those stiff white Extra flags, the Engineer must be quite near that on a fine afternoon !

By: ngineered4u

ngineered4u — Fri, 24 Mar 2017 12:43:04 +0000

@mercer. Possibly the trains were much shorter and lighter and did less wear. In 68 the York Sub was also fairly new as Mac Yard was only a few years old then.
There is now only 1 diamond on the York Sub at Doncaster (30mph) the other 2 were removed. The former diamond at Brampton is not a true diamond anymore as it is straight railed for the CN and is good for 50mph as is the one at Carew which is good for 60mph. As I said before Melrose on the Strathroy is 25mph. Progress right.

By: mercer

mercer — Wed, 22 Mar 2017 12:55:03 +0000

I have to jump in now. You need to ask the question – why are those CN diamonds, today, only 30mph ?
I have a CN TORONTO AREA timetable from April 1968 and all three diamonds on the York Sub were the same as the overall subdivision speed limit – 50mph. The Cayuga Sub was laid with 100 or perhaps 110 lb. rail and carloadings through the 1960s were limited to gross 263,000 lbs. So the comparison to today’s railroading, at 122 lb rail and gross loading limits of 286,000 lbs is relevant. So again, how are we making progress if 50 years ago the diamond speed was 50mph and today it’s 30mph ??

By: ngineered4u

ngineered4u — Wed, 22 Mar 2017 02:31:47 +0000

Yes snake, thats why i think the diamond was rated for a higher speed.

By: snake

snake — Tue, 21 Mar 2017 13:34:09 +0000

Anyone consider that when these speeds were posted…locomotives and cars were much smaller and lighter…We’re talking the 40 foot box car era.

By: ngineered4u

ngineered4u — Tue, 21 Mar 2017 00:46:09 +0000

@ Stephen.Good to know. Funny that train speeds over CN’s diamonds are (were) slower now than before. So much for progress. Still 30mph and Doncaster and 25mph at Melrose!

By: Stephen C. Host

Stephen C. Host — Tue, 21 Mar 2017 00:09:00 +0000

Phil, From the October 26th 1975 Timetable, for the Cayuga Subdivision under “Interlockings” shows

“3.2 – Railway crossing at grade
Crossing Dunnville sub…..mileage 42.8….. automatic. Permissable speed 50 miles per hour.”

Even the TH&B Crossing at 34.3 (E&O Diamond?) and the Penn Central Double main track crossing near St. Thomas is listed as 50 MPH.

And that was 10+ years after this photo was taken!

By: ngineered4u

ngineered4u — Mon, 20 Mar 2017 23:59:14 +0000

@mercer… hey do you have a timetable from that era? I find it interesting that the diamond would be good for 50mph way back then. Modern diamonds on CN have had very slow restrictions until the last few years. It was not long ago that all CN diamonds in Ontario were restricted to 30mph. Only in the last 5 yrs or so has the diamond at Brampton been raised to 50mph and thats because its not really a diamond anymore, same with the one at Carew which is good for 60mph The Doncaster diamond is still 30mph and the diamond at Melrose is 25mph. Perhaps the speed limit in the timetable was for passenger trains? I know in some locations passenger trains are allowed faster speed than freights.

By: Stephen C. Host

Stephen C. Host — Mon, 20 Mar 2017 22:38:06 +0000

This is nothing short of amazing.

By: snake

snake — Mon, 20 Mar 2017 17:49:21 +0000

Hey if anyone knows…Mercer would..after all..this was your era too…Eh Bruce?

By: mercer

mercer — Mon, 20 Mar 2017 17:45:18 +0000

To Clarify, the overall Subdivision speed limit in the 1960 timetable was 60mph for freight. At specific locations the speed was lower and at such time the diamond at Canfield ( Cayuga/Dunnville) was 50mph, as per timetable Special Instructions.