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That would would have a lot of consequences. though I see they sometimes terminate short at Three Bridges anyway. I am thinking that reverting to the relationships in the previous timetable might have fewer ramifications. Don't know where I can find it though. Seems to me the down Cambridge...

And? The ROC was specced in 2012 and opened in 2014 or therabouts. With generator backup. The battery power station technology would not have been competitive or mature at that time and there would be no reason to retrofit it, assuming the genny could be maintained in good order. In any case it...

Why would that be the case here? 1. if SPENW had cleared the fault in 90 secs that was presumably by switching something e.g. a faulty cable in/out, there was little time to do much else and none to change out any equipment, so why would/could that result in one phase being dodgy? 2. as the...

So were the battery chargers at my employers. If the FM had done nothing at all the battery would have been trickle charged and the system would have worked when called on for real. I recounted this story bc many failures of automatic systems are caused by a misguided intervention or someone...

Been looking at this a bit, hadn't realised how tight it is. Here is the regular pattern at Welwyn North (for last Wednesday) and here are the same trains by the time they leave Hitchin for Cambridge, taking 7, 14 and 13 mins so no overtaking going on. The intermediate stops mean that...

Still get repercussions of three phase faults though. On one occasion we had serious overvoltage that was said by DNO to be an imbalance caused by a neutral fault at a higher voltage level. We were away and came back to a failed solar inverter, it was replaced under warranty or I would have...

I was talking about the switch back to mains not being automatic for reasons explained by a previous poster.

Something like that. It's been said upthread that it is usual to require manual intervention to switch back to the mains, in case it is out of spec or not stable. To my mind this is not entirely sensible once the battery is about to give out, if the generator is not available there is not much...

I think I will have to find the time to plot it on all a Marey Chart. That seems to be the name in academic circles but was new to me, what are they called IRL?

As a point of detail (see under) two of them came from the same substation(!) But if it was a fault at a higher voltage two miles away then bringing a truly independent supply from a different s/stn might have been disproportionally expensive. And wouldn't have helped anyway as it was back on...

The big problem as someone has already said (?@Magdalia ?@MikeWM) is that the King's Lynns are not timed so they have the best chance of the window between slow(er) trains on the stretch from Hitchin to Shepreth Branch Junction. Finding them a better slot in the hourly cycle would improve the...

Someone upthread said 1 minute to full load. Also it might not be presented with the entire load all at once e.g. the aircon might be staggered. Well I think there are some deductions we can make. The UPS battery must surely be sized to last until you can be sure of the genny, so a few...

Maybe. There is some saving to be had by using a four-quadrant inverter which serves both as the charger and the output inverter depending on what the control circuits are telling the power FETs to do, this is how the Victron marine/domestic battery systems traditionally work. But where the...

As you said in post 150 they are separate 6.6kV feeders from alternate busbars in the same substation. Not what I would call truly independent though it might save you from a rogue pneumatic drill (if the routes are sufficiently well segregated). Also this.

BBC lunchtime news has confirmed equipment had to be replaced as per this item: Following the power cut, some of the systems controlling the signalling were damaged, so parts had to be replaced. That's why it's taken so long to fix the problem. Maybe they weren't working before, that's why...

Well in the extreme you would have a battery that could take the whole load for several hours. But at current prices and certainly when the ROC was equipped it is/was much cheaper to have a diesel generator to switch over to once its output is stable, then you only need a UPS/battery rated for...

We are there already. To use batteries effectively you need the means to charge them and also to invert their DC output to usable AC mains. And provide the controls for detecting grid failure and taking over the load mid-cycle. The combination of all this is what a UPS is.

You also need to have the lights on and the phones working. You don't need aircon for the first few minutes and you probably don't want to hit the genny or a UPS with all the aircon compressors trying to start at once so a sequenced recovery may be needed. (I have a whole house...

We don't know the generator didn't work. As @Annetts key says, it takes about a minute to start and be ready to accept your load. Maybe switching in a feed from the traction supply would be quicker but you still have to do it on a break-before-make basis or your traction supply is now feeding...

No such assumption. Only that there would be a functional UPS that would keep all the plates spinning meanwhile, which clearly didn't happen. Once that isn't the case every piece of equipment is going to need re-booting, ideally automatically on restoration of supply (but I expect a lot of...