For the record, the speed limits of the various switches in CN usage are fairly variable, in the sense if they are used back-to-back (to form a crossover) they are allowed a certain speed:
#20 - 45mph
#16 - 30mph
#12 - 15mph
Thanks for that information. Since we're on the topic, according to the GO Transit Track Standard Plans, the maximum recommended speeds through turnouts is the following (where L = lateral and E = equilateral):
- no. 8 L: 15 mph, not to be used outside of yards
- no. 10 L: 15 mph
- no. 12 L: 15 mph, unless all welded: 25 mph
- no. 16 L & E: 30 mph
- no. 20 L: 45 mph
- no. 20 E: 70/55/50 mph
- no. 8 L: 60' 11" (18.57m) or 67' 10 3/4" (20.69m)
- no. 10 L: 81' 6 1/2" (24.85m)
- no. 12 L: 98' 1" (29.90m)
- no. 16 L & E: 118' 5" (36.09m) or 139' 1 1/2" (42.41m)
- no. 20 L: 156' 0 1/2" (47.56m)
- no. 20 E: 167' 0" (50.90m)
Additionally, the design manual states the following:
8. On main track, only number 12 lateral and number 20 lateral turnouts shall be permitted, unless authorized by the CM Senior Manager of Track and Structures in writing.
a. Equilateral turnouts may be installed in select locations upon approval in writing from the CM Senior Manager of Track and Structures.
I should add for everybody's benefit that the numbers cited above are merely reference designs. They do not necessarily reflect any given turnout, most of which were designed and installed by other railways over many decades. Also, I'm a signalling engineer, so track geometry is at the boundary of my knowledge area: please take this with a grain of salt.