To what extent would it be practically possible to implement a new third rail scheme on the basis of
* no staff accessing track without an isolation in place (LU aren’t far from this position nowadays)
* secure fencing throughout
* no footpath crossings
This would essentially leave the only points of access being at road/occupation crossings, and station platforms, the latter could be mitigated with fencing and gates on the ends leaving the only practical means of trespass being jumping off a platform edge.
*Could* a scheme be made to work in this way from an operational point of view? I’m not asking whether it *should* be or whether it would be the best option, just whether it’s conceptually possible.
One other question, are we at the point where battery trains can match the performance of current DC fleets? Or to put it another way, is there a battery fleet currently available that could match the performance/timings of Electrostars were Uckfield to be electrified and operated by something like a 375/377/387?
It depends what you mean by “could”. Yes, physically it could as you propose. But it would be expensive, and certainly more expensive than an alternative that involved BEMUs and no third rail. I have no doubt it would not pass the AFAIRP test compared to BEMUs.
In the cases we're discussing, there's an assumption that the batteries can be recharged in normal operation on the existing 3rd rail sections.
Correct.
The Uckfield line, when the class 379 battery trial was being undertaken, was not far off the theoretical limit of battery life, meaning that there was very little contingency for the impact of any delay.
That was 12 years ago. Anyway, as always, if battery capacity is a problem, the answer is a bigger battery.
As the line to Oxted is a sustained climb, with trains working at full current draw on the ascent, that raises the possibility that the battery charging will need to be earlier in the journey.
Trains up to Oxted do not draw full current all the way, far from it. And, of course, it’s downhill from Oxted tunnel for nearly 9 miles.
However, the basic laws of physics remain in place. The charge used off the juice will have to be replaced, and the fundamental energy equations haven't changed. Regeneration will of course help, but can only do so much.
Indeed so, but regeneration direct into the battery is much more effective than out to the con rail and to substations. Besides, I saw the modelling for a battery train on the Uckfield line 14 years ago, and again about 8 years ago, and it is very straightforward to do with existing tech.
I have made my point on the basis of one depot death and no running line deaths for staff in 10 years and 4 fatalities/year, both divided by 20 for the maximum extension proposed, probably downgraded for the rural nature of the routes.
Yes, but not public deaths, of which there are many, none intentional, not all of which were trespass, and many were ‘unknowing trespass’ (including for example, the student who put his ear to the rail to listen for a train coming as he did in his native India - he knew no different), and none would have happened if the third rail wasn’t there. That is the point.
EDIT:
I’ll lay it out in simple terms, with made up numbers.
Let’s say to electrify the Uckfield line with con rail - all costs (infrastructure, trains, operation, maintenance, renewal) on a whole life cost basis - costs £100m. But the statistical modelling of safety risk shows there would be one additional fatality every 20 years due to the electrification.
Now we compare to alternatives.
Alternative 1: OLE
This costs £200m, but reduces the additional fatalities to one every hundred years, and serious injury to one every ten years. Essentially £100m extra to save 4 lives in a hundred years. That is grossly disproportionate.
Alternative 2: BEMUs
This costs £50m. Fatalities nil. Obviously, cheaper, safer, you do it.
But what if the cost is £100m? Same price, safer, you still do it.
But what if the cost is £200m? As with Alternative 1 OLE, that is grossly disproportionate, you don’t do it, and put down third rail.
Therefore somewhere between £100m and £200m there is a line between being a reasonable additional cost to avoid those fatalities, and it being grossly disproportionate.
That is what the assesment has to determine, using the value of fatalities (and injuries) avoided.
It is my contention, based on my experience of project and rolling stock costs, seeing previous studies for use of BEMUs on the Uckfield line (and applying the principles elsewhere), and the curent state of battery train development… that it is extraordinarily unlikely that a case can be made that extensions to the third rail for Uckfield, North Downs or Ashford - Ore would be the lowest reasonably practical level of safety risk when compared to the alternative of deploying BEMUs.