Great Western Coffee Shop

I read that Network Rail reckons it would be more cost effective to convert
existing 3rd rail electrification to 25KV overhead when the fixed DC
installations fall due for refurbishment/renewal. This conclusion is
based on detailed studies of the Basingstoke-Weymouth and East
Croydon-Preston Park lines.Conversion could commence during CP5
(2014-2019). http://www.rssb.co.uk/SiteCollectionDocuments/pdf/reports/Research/T950_rb_final.pdf
Thoughts.

I wonder if this is influenced by the HSE not liking 750v DC at ankle height...?! :o

No I do not believe so.

From experience of my day job renewing / enhancing is an expensive and complex task.   Basingstoke - Weymouth has power limitations especially west of Bournmouth, it was electrified to a tight budget the high voltage distribution is 11kV to increase capacity would need this increasing to 33kV which means all new switchgear, transformer rectifier units and aux power transformers also converting the track paralleling huts to substations, for this section of railway conversion to 25kV is also made more practical as there would be only 1 ac / dc interface it also make the potential of electrifying the Salisbury - Exeter line more appealing.

East Croydon - Preston Park this route has had a number of power upgrades the latest being done by Thameslink future dc options are becoming more challenging however this line is more problematical with more ac /  dc interfaces required also Balcombe Tunnel has limited head room.

In both cases and I suspect a number of others it will be cheaper to install a new style of electrical contact system that enhance the existing one; 25kV will also allow an increase in line speed third rail has a practical limit of 100mph

I am amazed that this idea is still being pursued.

Replacing the Third Rail would be a massive waste of money - yes, it's not ideal, but neither is overhead electrification.  There is little need for more than 100MPH running on the third rail system, particularly given the frequency of stops on most routes.

Of course, you can't replace the odd bit of third rail equipment as it becomes life-expired, you have to replace the whole system over significant sections of track.

In my view, there will always be much better things to spend the available money on than to replace one OK, but not perfect system of electrification with another.

Electrification of the entire Manchester and Leeds suburban systems, plus the Welsh Valleys, would be a start.  After Pacer replacement, of course.....and much more.

The Basingstoke - Weymouth line has severe electrical capacity limitations the substation equipment is rapidly becoming life expired although west of Bournemouth is new than the Basingstoke Bournemouth section it is limited in power and the equipment was put in by BR to a "budget".  It cost ^1M to renew a substation  and even more to build new additional ones, it is possibly more economic in both money and time to re-electrify the the line than to renew / enhance the existing.

The Brighton Mainline also has major power supply limitations which will limit the length and frequency of trains.

Both these routes have roiling stock that is ac / dc compatible the stock that is not can be cascaded to other routes

All this is fair enough but they either have to live within the constraints of the line or fully fund the alternative.   In the case of Basingstoke - Bournemouth, Waterloo - Bournemouth services would have to switch from third rail to overhead at, say, Basingstoke as the prospect of converting Waterloo to Surbiton has to be completely prohibitive.  Similarly Victoria - Purley.  Think of the massive disruption for a start, never mind the huge expense.

The railway would be seen to have gone mad and have no recognition at all of value for money if it continues to pursue this idea and particularly if taxpayers' money is expected to help fund it.  There are so many better causes.

Very interesting dilema for Networkrail.

I can see a case for Basingstoke Weymouth if it were coupled with Basingtoke Reading Oxford Birmingham, Birmingham Leeds/Doncaster. This would enable Cross Country to run at least their Bournemouth services with electric trains. Plus Basingstoke Exeter and Southamton Eastleigh Romsey Salisbury Westbury Chipenham/Bristol would enable the Bristol South Coast services to be electric..

As for the Brighton Line it's an interesting reversal of History the orignal LBSC overhed electrification got to Coulsdon North now it's proposed the wires start at Purley. Plus ca Change. Also with the Brigton Line I do think Uckfield Lewes should be reinstated and electrified. Although I gather it might be cheaper to do 25Kv from Oxted as the power supply would be cheaper.

If this change is to be seriously considered then I believe that a comprehensive plan to fully electrify South of the GWML via Badminton and Eastwards from Exeter. Including Castle Cary to Dorchester! Coupled with the CC links would save an awful lot of diesel oil.

The trouble is there are no Brunel's about the "Bean Counters" have knocked the stuffing out of British engineering.