Great Western Coffee Shop

...in this mornings HLOS:

http://assets.dft.gov.uk/publications/hlos-2012/railways-act-2005.pdf

To be 25kV OHLE as generally expected, but the extra surprise is that it carries on to Southampton, as part of a major north south electrified freight route. Change from DC to AC to be used as a trial section for a progressive update of the rest of the 'Southern'...   :o

Paul

The concept for has been in development for over a year.  There are a number of reasons other than a trial conversion the third rail traction substation equipment and high voltage supply network Basingstoke to Bournemouth is life expired, although installed in the 1960 some of the kit had been in storage for a number of years before it was used (originally intended for the East Grinsted electrification) also it does not have the capacity as it stands today for much in the way of electrically hauled freight and increased electric traction (cross country) passenger services

What does this mean for services out of Waterloo heading to Southampton, Bournemouth and Basingstoke I wonder?

Presumably all SWT's Class 444 Desiro's (and some of their 450s?) are going to get a pantograph and dual traction equipment fitted and will run 3rd rail London to Basingstoke, 25kv from Basingstoke to Southampton and back to 3rd rail from there to Weymouth?  Or will there be a new build of dual traction EMUs?  Either way it begs the question of what will happen to the many trains that don't currently stop at Basingstoke, as presumably they won't be able to change traction on the move?

444 and 450 are from a dual system family therefore they could be converted, equally they could be cascaded and new stock used.  My guess, the wires will not stop at Southampton, the 1980's electrification west of Bournemouth is weak to enhance the traction power supply (TPH conversion to substations) would require upgrading the 11kV supply network to 33kV which is costed at ^2m per site converted and that does not include any works required at Grid feed sites and installing high voltage cables along side the track.

It's not really a question of 'conversion', they are already wired and just need the relevant big lumps of hardware fitting.  There are clues in the cabs already, such as the control switches for raising the pantograph.  More a case of finishing them off completely...

Paul

Agreed, it is likely to be a little more than bolt a pan onto the roof, I am not sure if they have transformers fitted and there are a few other items that need bolting on and then the traction control software Ctr-alt-del  ;D

Ah, that's good then.  I knew that one of the coaches in each set already had a recess in the roof for a pantograph, but didn't realise that cab controls were fitted.  Any answers to my Basingstoke conundrum though?

AC / DC change over where needed.  With modern signaling and fiber optic telecoms and the right location they are quite simple to implement

Changeover on the move is possible, and at fairly high speed.  Eurostars did it at about 90 mph when they left CTRL/HS1 for the route round to Waterloo - Fawkham Jn I think. 

However it may be easier to do it during a stop anyway - probably cuts down the length of the dual section as well.  LO 378s are now routinely doing moving changeovers on the WLL by the way.

In the specific case of Basingstoke, it is only 1 train each way per hour non-stops, so adding that stop wouldn't exactly kill the timetable...

Paul

Point taken, though I doubt SHRUG will be too impressed!  It's also more than 1tph in the peak hours where in one hour no less than four up trains don't stop there.  Perhaps a high-speed changeover on the move can be installed as you suggest?