Great Western Coffee Shop

Network Rail Route Plans 2009 for Reading to Penzance (via B&H) mention a project for 2011/2012 to provide "Unified linespeeds between Reading and Exeter" the output aim being "Improved reliability, capacity and journey times".

What will that "unified speed" or in reality perhaps "speed range" be?  (A diagram in the document indicates a current range of 80-105mph from Plymouth to the Reading side of Westbury and 110-125mph from there to Reading)

What an interesting question.

Whilst I could probably envisage 125 from Westbury to Reading 105 from Plymouth to Westbury seems very ambitious given the gradients and curves between Plymouth and Newton Abbot then the sea wall from there to Exeter. 105 from Exeter perhaps?

Perhaps they should have said a higher lower speed for the range. 

Possibly it may mean a lowering of line speed in places, to make trains more fuel efficient and to diagram paths consistent a unified speed make this easier than a lot of variables along a route.   There may be some engineering that can be done to increase line speed in places but this has to be balanced against the gain.

Passengers often want a reliable arrival time they really are not interested if they are traveling at 100 mph or 110

The maximum line speed on the Berks and Hants is 110 mph.  This consists of a 110 mph section around Newbury and 2 110 mph sections between Pewsey and Westbury.  There are no 125 mph sections.  Due to the curvature of the route in many places significant speed increases are not likely.

The Main Line (MLN) from Bristol to Exeter would be much more suitable for any speed increase.

That's why IEP should have tilting, to enable 125 running on more curvy sections of line. Yes, we all know that the line to Bristol does not need tilt. But further West/South it is.