There is an additional service each way in the peak for the Pompey Direct from December which should help a little
Anything additional is of course welcomed. The elephant in the room (in relation to the Pompey Direct) has always been that some commentators refuse to accept that the nature of the SW network is such, that most services on all the longer routes, PDL included, have to form a part of the overall integral service pattern, just to keep up with demand, as the infrastructure from Woking Junction inwards will not permit any one route being given cart blanche to run everything for the sole benefit of those who travel from/to the outer reaches of those routes.
Whilst some within the industry have allegedly (I have heard) used (abused?) their position to enhance service levels at certain station(s) over the years, Moley having highlighted one specific example of recent times which was also mentioned to me by someone (no name, no pack drill), the industry in general has to take a wider collective view of the overall situation, whereupon the word 'compromise', is something that the users of all routes must accept at some point or other.
Maybe there is an option for tighter turnarounds. Do units layover longer than they used to?
As HamworthyGoods has replied, end of !
To explain turnrounds in timetabling planning in simple terms;
The SW timetable is driven by the capacity, platform occupation and track layout/signalling at Waterloo. Once you have got your head around that and accept same, the rest falls in to place. Plan Waterloo to it's optimum, but legally (by the rules Networkrail have in place) plus a number of small 'firebreaks' (to use the phrase of a-another above I seem to recall?), you will have a fair base for the overall timetable.
Each group of routes (at Waterloo) had its own guidelines/rules, ie, Windsor lines, main lines, main suburban lines.
These rules included such things as minimal turn round times, line of route operation (ie: Weymouth in, formed Weymouth out etc), crew related matters (which I won't go in to here) etc.
After that, connectional opportunities, stopping patterns, frequency, single line sections, junction conflicts (I could go on) need to be planned, and accounted for along the various routes. The last thing that would emerge from all this, would be the turnround times at the country end termini.
Sometimes these would work out OK by chance, but at certain places, Portsmouth Harbour being the most notable in my time, one was met with similar headaches to get around, albeit on a smaller scale in one sense, but also added to by the presence of trains from two other operators, and their associated wishes for their own timetables.
To sum up, turn round times at some outer location may seem excessive to the layman, eg at Alton perhaps, but that is a result of the overall plan as above.
But that does also allow for late running on the DOWN, and also allows for any train (on that route) to be maximum formation (ie: 12 car 450).