TRIVIA - Places where the mainline is slower than an alternative route

[duffield]

Nottingham to Birmingham, bypassing Derby using the freight line from Sheet Stores junction to Stenson Junction - as used for diversions during the recent Derby resignalling. Probably about 10mins quicker, avoiding reversal at Derby.
Hopefully might get used one day for an extra 'express' service from Nottingham to Birmingham, in addition to the 2tph currently via Derby.

 

[Big Chris]

Would the Queen Adelaide balloon loop qualify, Thetford to Peterborough is quicker via the balloon loop than via Ely, not sure if that is enough of a deviation under the OP's rules?

 

[Taunton]

The Catford Loop from Bromley to London Victoria seems to fit the criteria, the Main Line is via Herne Hill, but fast trains are regularly sent round The Loop (often with zero notice) to get there quicker, typically because they would be delayed by a stopper in front on the Herne Hill line, and in fact then commonly arrive at Victoria even ahead of the stopper.

 

[yorksrob]

Assuming Fawkham Junction could be used, which I'm not sure about, Ashford to Charing Cross via HS1, Fawkham Jn., St Mary Cray, Chislehurst would perhaps be marginally quicker than a non-stop train via Tonbridge. Probably only by about 5 minutes, if that.

Now that would have been an interesting route. The old Javelin route retention train used to go to Vic. Perhaps they could try a version via this route to Charing Cross (although my preference would still be an express via Tonbridge !).