Southern Railway - Electrified Branch Line Services

[Nearholmer]

Ah, the gearing only becomes an issue in a mixed rake. 

 

Empty beer and and pop bottles.

[Zomboid]

Presumably it's a control system issue more than anything else. And one that is still out there since 14x and 15x stock (75mph) can work in multi with 90mph 158/9 stock and 100mph 170s.

 

How are the camshafts in those old units controlled? Directly from the power handle position would probably cause the wrong notches to be selected in a mixed speed set.

[Nearholmer]

Resistance controlled trains progress through the notches according to current, next notch being taken as current falls to a given level. 

 

Because current draw draw is a function of back emf, which is a function of shaft speed, differently geared sets will progress through the notches at different rates, and will ‘top out’, to balancing speed, at different road speeds.

 

So, a mixed rake will surge and fight between sets - it’s like a three-legged race with a 4ft 6in chap and a 6ft 6in chap tied together, each attempting to run at their natural stride.

 

 

 

 

Edited July 1, 2019 by Nearholmer

[Oldddudders]

6 hours ago, Nearholmer said:

Gearing was an issue, in that main-line and suburban units had different ratios, but there were, IIRC, a few main-line geared EPBs that used to run out as far as Tonbridge ....... OD will correct me of I got confused.

At least 50% mainline stock was the required mantra.

 

As for express geared EPBs, right back to the late '60s, 5357 and 5358 - maybe others - were given 90 mph gearing. I think their diagram was 06.47 Eastbourne - London Bridge, ECS to Streatham Hill and then a Vic - Eastbourne working in the evening. I am less familiar with mainline-EPB workings on the SE, but do recall the 17.16 Victoria - Sheerness included a 4 EPB, which made for distinctly cosy accommodation for a courting couple after Sole Street, given that train's tendency to be held awaiting the road at Rochester Bridge Junction......

[Nearholmer]

Just found this, which gives some detail on express gearing of EPB, but is imprecise on dates of conversion to suburban gearing https://www.bloodandcustard.com/epbbr001.html

 

There were definitely EPBs stabled at Tonbridge in the Down sidings on the London side of the station in the mid/early 1970s, which I was told were express geared ones for use on some train that I think must have gone to London very early, then come back, and had a rest until doing the same again in the evening. Even as a spotty youth I thought it sounded a tad wasteful, but then there were other very weedy diagrams at the time, like the Hastings unit that made one trip to Eridge, and two to Edenbridge in a day, and a three-set of Mk1 that seemed to be used for one Reading - Tonbridge trip and return.

 

 

[roythebus]

On my drivers course we were told we could mix EP and main line stock, maximum speed was that of the lowest speed rated stock as with all railway stock. Different acceleration rates could be a bit jerky. We had mixtures of them on the Waterloo-Reading services as well as other lines.

[keefer]

This came up in a topic a while ago - I was aware that some HAPs were built with express gearing but didn't know about the EPBs. 

The Reading-Tonbridge via Redhill always only seemed to have whatever could be cobbled together - gaining the 'Tadpole' units as a low cost solution to keeping the service, before it eventually went over to WR DMUs

Edited July 2, 2019 by keefer

[KeithHC]

11 hours ago, Nearholmer said:

Just found this, which gives some detail on express gearing of EPB, but is imprecise on dates of conversion to suburban gearing https://www.bloodandcustard.com/epbbr001.html

 

There were definitely EPBs stabled at Tonbridge in the Down sidings on the London side of the station in the mid/early 1970s, which I was told were express geared ones for use on some train that I think must have gone to London very early, then come back, and had a rest until doing the same again in the evening. Even as a spotty youth I thought it sounded a tad wasteful, but then there were other very weedy diagrams at the time, like the Hastings unit that made one trip to Eridge, and two to Edenbridge in a day, and a three-set of Mk1 that seemed to be used for one Reading - Tonbridge trip and return.

 

 

 

I seam to recall there where 4 3coach fixed sets of BR MK1s retained for Reading Redhill Tonbridge services. Mainly used on the Reading Redhill section. There where also short workings from Redhill to South Godstone during school terms. I believe one set was also used at Brighton to strengthen the weekend Plymouth services.

 

Getting back to the original post there is also a modern example of mixed traction on a single line branch in SR region. That is the Lymington service which is EMU weekdays and DMUs on weekends.

 

Keith

[Nearholmer]

I think a lot depends upon exact date, with the loco hauled trains on the Redhill Line declining in number, then ceasing altogether, over a period of about ten years.

[DY444]

12 hours ago, Oldddudders said:

At least 50% mainline stock was the required mantra.

 

 

50% was certainly the case for EP stock control gear.  For 51 stock in multiple with 57 or 63 stock then at least 50% of the motor caches had to be the latter (with CIG, BIG and VEP motor coaches counting as 2) but I don't recall it applying to gear ratios, officially anyway.

[Geep7]

Can't believe i've only just found this thread.

 

When trying to justify why my own single track SR BLT is electrified, I pretty much invoked rule 1, but further investigation found the Sheerness branch does give a pretty good prototype.

 

It's double track from Sittingbourne, through Kemsley, to just before Swale station, where it goes down to single track to go over the Kingsferry Bridge, it continues as single track all the way to Sheerness on Sea, except for a passing loop at Queenborough.

 

OK, the train service isn't massively exciting these days, just a shuttle between Sheerness and Sittingbourne all day, with a couple of peak-time trains during the week running through to London. I'm not sure what the service was like back in the 60's, but was probably not much different, but perhaps with additional freight and parcels traffic.

 

Interestingly, I believe the Kingsferry bridge is not electrified across the lifting section, with trains having to coast across the gap. I'm not sure how long the gap is, but I wonder if there has been an occasion of a stranded train in the past?

[Oldddudders]

2 minutes ago, Geep7 said:

 

Interestingly, I believe the Kingsferry bridge is not electrified across the lifting section, with trains having to coast across the gap. I'm not sure how long the gap is, but I wonder if there has been an occasion of a stranded train in the past?

Mike Storey of this parish worked the patch a few decades ago - he may have some idea if it ever happened. 

[Wickham Green]

41 minutes ago, Geep7 said:

......... OK, the train service isn't massively exciting these days, ......., but perhaps with additional freight and parcels traffic. ........

No 'perhaps' about it ............ Sheerness Steel was very busy with rail traffic well within living memory - though not into the terminal platforms, of course.

[Zomboid]

4 hours ago, Geep7 said:

 

Interestingly, I believe the Kingsferry bridge is not electrified across the lifting section, with trains having to coast across the gap. I'm not sure how long the gap is, but I wonder if there has been an occasion of a stranded train in the past?

The span is about 40m long, so no risk at all of a 4 car getting stuck unless it's missing some shoes. You'd have to be really unlucky to get stuck in a 2 car.

[brushman47544]

On ‎28‎/‎06‎/‎2019 at 16:33, Joseph_Pestell said:

Not a branch terminus exactly, but more compact than many of those, was Reading South. I think that it has been modelled, many years ago. Electric trains from London, steam from Tonbridge/Redhill until 1965 (and even London via Redhill as a parcels working).

 

For many years there was an up morning and down evening through train between Reading and London via Redhill. The train joined/split at Redhill with the other portion going to Tonbridge - and beyond? I've seen photos of Schools V class locos hauling it towards the end.