There has been much in The News about a faster service to Waterloo from Portsmouth. Of course, unless the trains run non-stop there is little to be done about the time it takes.
The main reason is the topography of the countryside between Havant and Woking. It is all up hill and down dale with many curves.
There are also speed restrictions to contend with through Rowlands Castle, up and down Buriton Bank and through Witley.
There could be trains capable of running as fast as a Eurostar, 180mph+, but they would still have to keep to the limits, down to 60mph in sections.
One must also remember the Portsmouth line is no more than a branch off the main line from Woking junction.
The fast lines are down the main line to Basingstoke and Southampton.
For several weeks in the autumn of 1963, the main line services were diverted from Southampton to Woking via Fareham and Havant because of engineering work. A schedule was made for one of these services and how the train ran is shown here.
The normal running time for a modern train, say the four minutes past from Havant, is 41 minutes calling at Petersfield and Haslemere.
The 1963 trains were scheduled to hit 52 minutes non-stop for the journey and, as can be seen, ran within the allotted timings.
Unless new tunnels are built and cuttings made to keep the line on some type of level, the only way to increase the speed between Portsmouth and Woking is to run non-stop.