Their profile does not fit in oxted, neither does and mk3 based stock
As an educated guess - The sharpish reverse curves are probably a big part of the reason
Their profile does not fit in oxted, neither does and mk3 based stock
Maybe the signalling could be another hurdle. The type of track circuit changes as the line ducks under the redhill-tonbridge's due to the D.C traction interfering with the non electrified Uckfield lines.
Not sure on signalling vs electrification costs mind..
Not sure I understand the question you finish with. I hate to think how much the platform extensions cost. Today's railway seems to fall into the 'Stick an extra zero on the bill" category.
Benefits of redoubling? Put it this way - a single line sectioned railway is half a railway twice as likely to go wrong. Electrification benefit? Is it not a benefit to integrate a busy commuter railway into a predominantly 3rd rail network thus doing away with the need for route specific trains thus releasing diesels to lines that need them? Neither of these jobs are difficult and if there is more hands on project management by NR, costs will hopefully fall.
Platform extensions? Well I would have put them 3rd in the list of priorities. A longer platform accomodates longer trains and you can't walk through a 10 car 171 and the extension cuts out the need for selective door opening.
Putting it simply:
Platform extensions cost (from memory) around £15-20m. And enabled an immediate beenfit to passengers in the form of longer trains, ie passengers had a much better chance of a seat indeed a much better chance of actually getting on the train.
Redoubling and electrification, by themselves, offer little benefit to passengers. As capacity on the network is limited through Croydon and into London, doubling would not offer any additional trains. It would offer a small performance benefit, but that is at the margins. Meanwhile electrification would offer many benefits to the rail companies (lower maintanence costs, lower fuel costs) but little benefit to passengers. Unless of course the platforms were extended. And the cost of redoubling and electrification would easily be £200m.
So, spend £20m on something that provides noticeable benefit to passengers, or 10 times as much on something that, frankly, doesn't.
Do you know what the impact on journey times would have been?
Well they're both quite expensive.
But then again, NSE seemed to manage third rail electrification during the 'dark days' of BR, so perhaps not so much.
A lot of late BR schemes (especially Weymouth) appear to have been cobbled together largely with existing manpower and plant equipment.
And the only new rolling stock items purchased were the Mark 3 bodyshells/interiors (in the Weymouth case).
And in some cases (Merseyrail) appear to have ad no new rolling stock purchased at all.
Can't do anything like that in the 'modern' railway.
A subtle hint:
the the first pair of questions lead to a good BCR and fairly low cost, the second pair of questions lead to an abysmal BCR and high cost.
Hence why the platform extensions were the first on the list.
Putting it simply:
Platform extensions cost (from memory) around £15-20m. And enabled an immediate beenfit to passengers in the form of longer trains, ie passengers had a much better chance of a seat indeed a much better chance of actually getting on the train.
Redoubling and electrification, by themselves, offer little benefit to passengers. As capacity on the network is limited through Croydon and into London, doubling would not offer any additional trains. It would offer a small performance benefit, but that is at the margins. Meanwhile electrification would offer many benefits to the rail companies (lower maintanence costs, lower fuel costs) but little benefit to passengers. Unless of course the platforms were extended. And the cost of redoubling and electrification would easily be £200m.
So, spend £20m on something that provides noticeable benefit to passengers, or 10 times as much on something that, frankly, doesn't.
As an educated guess - The sharpish reverse curves are probably a big part of the reason
Yup they are pretty sharp basedon this pic: https://500px.com/photo/116554929/oxted-tunnel-1-by-adrian-backshall
Re earlier posts about mooted costs of platform extensions etc on the Uckfield line.....£20 million or so just to extend platforms, up to £200 million to electrify and restore to twin track? Really? 30 years have passed - but BR electrified Hastings Tonbridge with associated infrastructure work for around £25 million. I hate to think how much NR would pay for that today.
How many trains per hour pass through there? Would it be low enough to make singling the track through the tunnel, to allow a more types of train? Where is that approx on Google Earth? Looking at the track south of Oxted it doesn't seem that sharp. Would it cost tens of millions or hundreds of millions to alter the tunnel itself?
How many trains per hour pass through there? Would it be low enough to make singling the track through the tunnel, to allow a more types of train? Where is that approx on Google Earth? Looking at the track south of Oxted it doesn't seem that sharp. Would it cost tens of millions or hundreds of millions to alter the tunnel itself?
£BIGNUMBER
...does anyone know why it was built in such a manner in the first place? I can't imagine you'd do something like that unless you had to.
Ah, good old BR days, when cost accounting was a little, shall we say, adventurous.
How many trains per hour pass through there? Would it be low enough to make singling the track through the tunnel, to allow a more types of train? Where is that approx on Google Earth? Looking at the track south of Oxted it doesn't seem that sharp. Would it cost tens of millions or hundreds of millions to alter the tunnel itself?
The northern part of the tunnel
I'm sure I read somewhere that Oxted tunnel is a rebore. The original tunnel wasn't finished due to serious geological issues or something like that. So geology is likely to have played a major role in how the tunnel was re-bored. Either that or Victorian surveyors were crap.
Anyway I suspect someone will confirm/correct me!
You're basically correct. It was something of a project of several parts, by accident of history vice intention. The design was modified to make it shorter (originally Marden Cutting, beyond the north portal, was meant to be in tunnel too, apparently), then partly dug, and then finished some time later, with a rebore through a section which was deemed less than ideal. To make matters more complicated, there are also hidden rooms and shafts in the vicinity of the tunnel, according to my esteemed colleagues who have worked on it.
Ah, good old BR days, when cost accounting was a little, shall we say, adventurous.
Meaning?
Now that EMU's are apparently available like candy from a sweet shop, electrification would at least allow DMU's to be cascaded to strengthen the Ashford - Brighton service.
Redoubling and electrification, by themselves, offer little benefit to passengers. As capacity on the network is limited through Croydon and into London, doubling would not offer any additional trains. It would offer a small performance benefit, but that is at the margins. Meanwhile electrification would offer many benefits to the rail companies (lower maintanence costs, lower fuel costs) but little benefit to passengers. Unless of course the platforms were extended. And the cost of redoubling and electrification would easily be £200m.
So, spend £20m on something that provides noticeable benefit to passengers, or 10 times as much on something that, frankly, doesn't.
As for rolling stock issues, surely Southern could use Electrostars down there in the event of electrification with either power source? Be it 387s or even a swap for some of SEs never touched the AC 375s?
Meaning that whole tracts of cost were not accounted to the project. Design? In corporate overhead costs. Engineering trains? Same. Often the gangers doing the work were costed to the local renewals / maintenance budget. Lost revenue? A reduction on the income line.
All of which means that a cost reported of, say, £25m in 1987 is very unlikely to have been the actual cost of the project. This suited BR very well, as it enabled more projects to be put through the DfTs rules on investment. Back then, any project over £2m required Secretary of State approval, and would only get that approval if it generated a cash return on investment of 8% or more. Socioeconomic and environmental benefits could not be counted. I know of some junction renewal projects where the cost reported was basically the cost of the materials; everything else was accounted for in operating budgets or overheads.
Also back then, DfT involvement in the detail of running the railway was almost non-existent. BR had cash targets to meet, but these were basically based on the previous year. There was a huge corporate overhead, which covered al sorts of stuff that should have been allocated to projects, but wasn't.