Has Dorking always had long signal sections?

[infobleep]

The Sussex route plan - from 2010 but signalling is very unlikely to have changed - here (pdf download, 1MB) declares in the appendix on page 32 that Dorking to Horsham has a signalling headway of 9 minutes. This probably isn't inaccurate[sup][Citation Needed][/sup].

However, I suspect it only has 2 aspect signalling (like the East Grinstead branch, which has an 8 minute headway). If I am right, this means that in practice you would not e.g. schedule consecutive 9 minute headway trains all day, as if any single one of those was even slightly late then it would delay every single train behind it for the rest of the day. Compare with a 3 or 4 aspect line where every signal can show yellows, allowing trains to start moving sooner behind a delayed train. You thus expect to run well below this capacity, to stop the schedule from falling apart.

4tph is the maximum I've ever seen scheduled down the East Grinstead line. To me, 3tph thus sounds like a reasonable upper bound for a reliable timetable via Ockley, although 4tph is conceivable if 9 minutes is accurate. When combined with power supply issues and finding enough train crew, enough trains and decent paths through Dorking, Epsom and Sutton it perhaps isn't considered necessary or practical to try and run this.

Has Dorking always had long signal sections?

 

[HarleyDavidson]

They were long even when SWT went down to Horsham.

Holmwood box was usually locked out & Warnham was only there to do the gates. IIRC there was an IBS somewhere along it, but I can't remember where it was now or even if it's still there as we don't go there anymore, which is a shame because it was a nice run and made a change.

The section down to Horsham from Dorking is very under utilised, with just an hourly service during the day and ½ hourly during the peaks, plus an early finish with the sole late one from Dorking @ 0026, the previous one being 2019.

Last service towards Horsham on a Saturday is 1824 & No Sunday services run.

 

[30907]

Has Dorking always had long signal sections?

Short answer is yes. The 1978 Sectional Appendix shows boxes at Holmwood and Warnham, the box at Ockley having closed, and doesn't list any Intermediate Block Signals. I'd guess the present signalling is effectively like for like? (Harley Davidson has beaten me to it!)

 

[infobleep]

They were long even when SWT went down to Horsham.

Holmwood box was usually locked out & Warnham was only there to do the gates. IIRC there was an IBS somewhere along it, but I can't remember where it was now or even if it's still there as we don't go there anymore, which is a shame because it was a nice run and made a change.

The section down to Horsham from Dorking is very under utilised, with just an hourly service during the day and ½ hourly during the peaks, plus an early finish with the sole late one from Dorking @ 0026, the previous one being 2019.

Last service towards Horsham on a Saturday is 1824 & No Sunday services run.

Thanks. Never knew South West Trains went to Horsham. Interesting.

However before the signal boxes were locked it of use, does that mean the sections were shorter? I'm thinking 60s and earlier.

 

[yorksrob]

Short answer is yes. The 1978 Sectional Appendix shows boxes at Holmwood and Warnham, the box at Ockley having closed, and doesn't list any Intermediate Block Signals. I'd guess the present signalling is effectively like for like? (Harley Davidson has beaten me to it!)

V Mitchell & K Smith's excellent book on the Epsom - Horsham route lists Lodge Farm crossing box between Dorking and Holmwood, which was an intermediate block post until electrification, and Northwood block post between Ockley and Warnham. Used peak times until 1927 and bank holidays until 1956.

 

[30907]

Dorking to Holmwood was the longest section, about 9 minutes for a 4SUB. Checking the pre 1967 timetable, there must have been a down IBS as the stoppers followed the mid Sussex fasts only 5 minutes later. Indeed, the LBSC 1910 timetable required one!
However, the Up timetable didn't require an equivalent (and of course Dorking doesn't have an up loop) - memory says it's noticeably downhill, so there was presumably less of a need, especially in steam days.

BTW Holmwood SB is Grade 2 listed, being a surviving platform level box.

And Yorksrob was quicker.

 

[infobleep]

Dorking to Holmwood was the longest section, about 9 minutes for a 4SUB. Checking the pre 1967 timetable, there must have been a down IBS as the stoppers followed the mid Sussex fasts only 5 minutes later. Indeed, the LBSC 1910 timetable required one!
However, the Up timetable didn't require an equivalent (and of course Dorking doesn't have an up loop) - memory says it's noticeably downhill, so there was presumably less of a need, especially in steam days.

BTW Holmwood SB is Grade 2 listed, being a surviving platform level box.

And Yorksrob was quicker.

Good to hear that the box has been able to be left in place. Some listed boxes get moved. Such a Barnham. I understand why the need might exist to do that.

 

[The Planner]

6 minute headway following a non stop, 9 following a stopper.

 

[physics34]

alot of rough rides on the route though. I sign the route......

 

[Deepgreen]

Thanks. Never knew South West Trains went to Horsham. Interesting.

However before the signal boxes were locked it of use, does that mean the sections were shorter? I'm thinking 60s and earlier.

As far as I know SWT per se didn't serve Horsham (I think the Waterloos ceased prior to privatisation), it was BR(S)(SW division) - usually 4 or 8SUB/EPB with headcode 15.

 

[tsr]

alot of rough rides on the route though. I sign the route......

So do I! One or two speed restrictions were also making life awkward last time I went down there. I was due to head down the line a few times over the next month or so, but not any more; but even without popping down the "Back Road", I can imagine that the 2tph diversions over Christmas have not exactly improved matters.

Regarding signalling, one of the issues is that even with acceptable headways for (say) 4tph, should demand exist, then you could potentially end up with trains stuck in some quite awkward locations without potential for crossover moves, should anything go wrong. For example, if you dispatch off a single yellow on a Dorking starter signal going Down Portsmouth, you will potentially end up stuck at CBK7 at Betchworth Tunnel; this is not at all helpful and as a result platform staff will now recommend that control or the signaller advise if there is any sort of obstruction on the line before continuing further. I can recall at least one occasion when a driver has asked to wait on the Down platform at Holmwood rather than drawing up to the starter beyond the platform (which is permitted) as they did not want to have to make a wrong-direction move should anything have gone awry on the line ahead. All this can potentially waste time and strand passengers (sometimes briefly, sometimes for longer) in the event of an incident.

I much prefer better spacing of trains between Dorking-Horsham simply because it allows a smoother service to run, and better chances for trains to hold in stations should there be any problems. There are admittedly few options for replacement transport from the intermediate stations if the buses are too large, but it does make life a lot more practical in general. 2tph is fine, but 3tph can be pushing it, and even if the power supply was there, 4tph could have trains stacking up very quickly if anything went the shape of the pear (and welcome to Southern in rush hour, by the way...).
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Dorking to Holmwood was the longest section, about 9 minutes for a 4SUB. Checking the pre 1967 timetable, there must have been a down IBS as the stoppers followed the mid Sussex fasts only 5 minutes later. Indeed, the LBSC 1910 timetable required one!

As above, you now have a signal (Red/Green) on the Down at Betchworth Tunnel, with the tunnel between it and the axle counter section, and further R/G signals as Down Starters at Holmwood and Warnham. The Down Starter at Holmwood is obscured and therefore guards may dispatch towards it at red, if no other instruction is received (again, as above).

(For examples on the Southern network where this does not apply, see Clandon (beyond the crossover on the Up), South Bermondsey (slightly beyond the platform and visible to driver only) and Burgess Hill (visible in the distance but you must not draw forward).)

However, the Up timetable didn't require an equivalent (and of course Dorking doesn't have an up loop) - memory says it's noticeably downhill, so there was presumably less of a need, especially in steam days.

Dorking effectively has 2 Up loops. Platforms 2 & 3 are bi-directional. Both can be used for through passenger traffic in either direction. Platform 1 is for Up traffic only in passenger service; a Down shunt into the platform is available.

BTW Holmwood SB is Grade 2 listed, being a surviving platform level box.

There's plenty of stuff still in there, but it's in a terrible condition. Not exactly at the levels that Eridge was before it was demolished, but it's completely unusable and sadly looks very unloved.

 

[HarleyDavidson]

As far as I know SWT per se didn't serve Horsham (I think the Waterloos ceased prior to privatisation), it was BR(S)(SW division) - usually 4 or 8SUB/EPB with headcode 15.

Oh yes we did! I used to sign it. Then they turned their eyes onto West Croydon which was a waste of time as it followed a CSC (as it was then) all the way to West Croydon.

I'd still like to return to Horsham some day.