Snow1964
Established Member
There is quite a balancing act on how much time is saved.810s will run on overhead power from St Pancras to just North of Cricklewood station the run on Diesel power to Bedford in down direction , into London Up , pan down at Bedford until just North of Cricklewood , 5miles 30ch to be exact where line speed changes from 95 to 110 mph with a 100 mph restriction for EMU.
ApCo Balise ( automatic power control) gubbins and signage will be installed to mark raise/ lower pan area.
this will be the case until catenary is upgraded, around 200 locations require adjustment for higher speed electric operation.
St Pancras will be diesel free.
Most likely first revenue use of 810 will be before this work is completed even with some large weekend possessions in 2024 .
Very roughly it is 44 miles from Cricklewood to Bedford, but few bits are never going to get to 125mph, so let's call it 40 miles max. A train doing 120-125mph could cover it in 20 minutes, more realistically 21-22 minutes as needs to accelerate to top speed once get on fast bit.
At 100mph, the 40 miles will take about 27 minutes, so about 5 minutes longer than 22 minutes. However there are few bits with speeds between 100 and 125mph due to curvature etc. Slowing down bit and then accelerating back to 125mph few times, is going to eat into another 1-2 minutes. So the upgrade to 125mph only really gains about 4 minutes.
I do not know if 810s can change system at 100+ mph on full power, I suspect in reality likely to be 20 seconds of coasting, during which bit of speed will be lost. To put it into perspective that 5 minutes, doesn't even restore the extra walk time to tube or road in front of St Pancras which was added when trains were moved outside the Barlow shed.