Bournemouth Electrification

[Southernman46]

Also worth being in mind that the damp string that is the BML electrification is, well, damp string. The substation at the junction may not have the capacity to support the 10s & 12s on the main line as well as an electric branch service.

It's not and it can

[lapford34102]

As someone who's used the Weymouth-Waterloo line at least a couple of times a year for the past 50 years I could drone for ages about various things, but will try not to.

As someone has said the current 1/2 hourly service  would have been unthinkable 50 years and if it had been in operation then more than a few would have likely asked why.  Travelling patterns have evolved and while end to end times haven't improved significantly neither have they increased. In the 60's and early 70's you could pretty much guarantee your own company by picking the seating bay nearest Weymouth's stopblocks which ever direction you were going. Not many got to the farthest coach at Waterloo. Most recent experience off-peak was pretty busy though I'd like a few quiet words with whoever rostered a 450.......

Best comfort 442, most fun ride REP/TC/33/1 (8TC+74 a contender for 3rd rail), the 444's are OK - the priority seats have already been mentioned, but do get a feeling or rather lack of it after a trip. Did anyone ever get a through trip on a CIG or a VEP after Wey got electrified?

Might be my memory but thought that originally access to Bomo TMD was going to be round the curve over the viaduct rather than Branksome and reverse but then the structural issues came to light.  Also Poole in 67 was a comparatively quiet smallish place but with  convenient sidings and run-round for Inter-regionals, kept them out the way and with easy access to TMD if needed.

Most evocative memory - the bark of the 33/1 as it went under the roadbridge at Branksome - in those days knew I wasn't that far from home :-)

 

Stu

[lmsforever]

Is the power turned on to Lymington as with a dmu in charge it would seem to be a waste of money in electricity.

[Foulounoux]

Is the power turned on to Lymington as with a dmu in charge it would seem to be a waste of money in electricity.

Electricity is only used when there is a demand And

The circuit isn't completed until a unit is powered up or a human completes the circuit !!

[phil-b259]

Electricity is only used when there is a demand And

The circuit isn't completed until a unit is powered up or a human completes the circuit !!

 

Not quite true I'm afraid as we have yet to invent a perfect insulator that will remain free from conductive environmental deposits - unless its kept in a vacuum. As such their will always be some current flowing round the circuit and power thus being used. On a wet day then it will probably be more than a dry day and it will obvious be relatively insignificant compared to a electric train completing the circuit - but its bad physics to ignore it completely.

Edited July 11, 2017 by phil-b259

[DY444]

The BML electrification was undoubtedly done at the lowest cost possible, but money was still found to electrify the Lymington branch (albeit with no substation beyond the junction). A strange decision considering that this was DEMU land, which could control and be controlled by the local EMUs.

 

Although the DEMUs had 27 way jumpers and EP brakes the jumpers were wired differently and were not compatible with any emus.  One DEMU was rewired much later to be EMU capabible but it was the only one.

[Southernman46]

Is the power turned on to Lymington as with a dmu in charge it would seem to be a waste of money in electricity.

There is a single High speed Circuit-Breaker that feeds the traction current to the Lymington Branch and it will remain normally closed unless arrangement has been made operationally by NR to remove the traction current from the branch - most of the cables down there are still 500mm copper and this would soon disappear if it become know that the traction is off - keeping the equipment on "soak" will prevent it degrading also - technically speaking just because SWT choose to operate a DMU does not mean that the breaker is open as any other operators' authorised electric traction can use the branch too at any time - SWT do not own exclusive rights to the SWD - despite what they may think ! 

BTW I think FG taking over is a complete disaster for the Wessex route - smacks of gving all the SR's west of Salisbury route to the WR in the sixties - I think we will see the WOE line get royally screwed ..............

[Ian J.]

I'm not aware there were any structural issues with the West to Gas Works Junc. viaduct. I thought it was removed from use due to the extra length needed in the carriage sidings?

[Zomboid]

It's not and it can

Anywhere with TCRs is a wet piece of string in my book.

[4630]

Also worth being in mind that the damp string that is the BML electrification is, well, damp string

There was quite a lot of investment in the electrification infrastructure in the early 2000s along the mainline to support the introduction of the 450s and 444s. They were described at the time by Roger Ford of Modern Railways as 'lard butts'. The beefing up of the electrical supply involved additional sub-stations at several places along the route.

[Southernman46]

Anywhere with TCRs is a wet piece of string in my book.

Back in the day when we first developed them they were a necessary evil - nowadays electronics have developed enormously detection circuitry & Mitre relays etc. have enabled better and more robust protection - in those days all we had was magnetic flux and CT's ..............  - now the BML 1988 electrification beyond Branksome I agree is ............... operational restrictions at the Weymouth end due to lack of 11kV capacity from Redlands Grid etc. ....... bit like the Hastings line beyond Tunbridge.

[Southernman46]

There was quite a lot of investment in the electrification infrastructure in the early 2000s along the mainline to support the introduction of the 450s and 444s. They were described at the time by Roger Ford of Modern Railways as 'lard butts'. The beefing up of the electrical supply involved additional sub-stations at several places along the route.

Indeed - a bit like as with the Networkers - the traction infrastructure is eventually catching up with the trains and I now believe regen working is possible between Woking & Basing

[Zomboid]

Back in the day when we first developed them they were a necessary evil - nowadays electronics have developed enormously detection circuitry & Mitre relays etc. have enabled better and more robust protection - in those days all we had was magnetic flux and CT's .............. - now the BML 1988 electrification beyond Branksome I agree is ............... operational restrictions at the Weymouth end due to lack of 11kV capacity from Redlands Grid etc. ....... bit like the Hastings line beyond Tunbridge.

They were a very good solution to the problem at the time (and a fantastically simple thing inside the box), and you're right that with modern kit they'd be unnecessary in most places.

Anyway, this might be straying a bit far into techie stuff...

[lapford34102]

 

I'm not aware there were any structural issues with the West to Gas Works Junc. viaduct. I thought it was removed from use due to the extra length needed in the carriage sidings?

You may well be right, said memory was suspect :-)

Anecdote re Bomo TMD. Late 60's on Sat we used to regularly jump into mates car after pubs had closed and drive from Wey to the 10 pin bowling at Branksome (i know, times have changed and so have attitudes) One night we came out when it shut - 2.00 am ? - and went to the car. There was a 33/1 idling beyond the fence which my dad just happened to be driving..........

 

Stu

[Foulounoux]

Not quite true I'm afraid as we have yet to invent a perfect insulator that will remain free from conductive environmental deposits - unless its kept in a vacuum. As such their will always be some current flowing round the circuit and power thus being used. On a wet day then it will probably be more than a dry day and it will obvious be relatively insignificant compared to a electric train completing the circuit - but its bad physics to ignore it completely.[/quote

 

 

 

I was trying to keep it simple. :-)

[jim.snowdon]

Although, in terms of practical engineering, the losses due to leakage across insulators are sufficiently small as to be considered insignificant in the overall scheme of things.

 

A contributory factor is that not only does the electricity have to leak out from the positive, but is also has to leak back in to the running rails in order to get back to the rectifier from which it came, as its negative terminal is not Earthed. (The running rails are not at Earth potential, but float at a voltage above or below Earth, the magnitude dep[ending upon the load being drawn, where the various loads (trains) are and the distances involved.

 

Jim

[AberdeenBill]

It's not EMUs in general that's the issue, it's that SWT don't have one available M-F to run the branch service. They'd have to hire in something specially which would be different from the rest of the fleet, which doesn't make sense when they also have a DMU spare.

It may go back to daily EMU operation if the 707s free up a 450 (but I have no insider knowledge of that).

Also worth being in mind that the damp string that is the BML electrification is, well, damp string. The substation at the junction may not have the capacity to support the 10s & 12s on the main line as well as an electric branch service. Weekend loading is lighter, so there could be headroom then.

 

Back in the late 1960s and early 1970s the summer Saturday service was pretty intense, with two 4-Rep + 2 x 4TC per hour both up and down on 91s (fasts) and 92s (semi-fasts) and a 4-Vep on the 93 (slow) and often a 12-Vep or 74 + TCs working reliefs in both directions.   Add to that an 8-Cig on the Waterloo to Lymington Pier direct service... 

 

Bill

[phil-b259]

I'm not aware there were any structural issues with the West to Gas Works Junc. viaduct. I thought it was removed from use due to the extra length needed in the carriage sidings?

 

A look at the current depot site on satellite imaginary tends to support this view as the place where the east curve comes into the depot is mid way down one of the carriage sheds. Had the entire railway formation (including the actual site of Bournemouth West terminus) been used then retention of the east curve may have been possible - but that would have clearly had an impact on BRs ability to sell off surplus land and / or the ability to route a new road through the West station site.

Edited July 12, 2017 by phil-b259