Thanks - I'm not familiar with the connections for Mk5s and didn't realise that the jumper is separate from the coupler.
So when ECS runs to Euston/GLC under normal operations, does the ECS loco detach and move forward before the "train" loco starts to provide power to the train?
Yes, after arrival the ECS loco detaches and moves forward a few feet. The train loco (usually brought in Dead on Rear) is then connected up ETS-wise prior to boarding.
For ECML diversions at Wembley is there a temporary lack of train power and reliance on batteries whilst the swap is done?
Yes - although it's a negligible time period. The train(s) arrive in Wembley Yard, draw-back loco detaches and the train loco on the rear/south end (already attached) is hooked up.
Also worth noting the issue is more to do with the 61-way (data/comms) jumpers being attached at each end and stray currents flowing into the loco and frazzling electronic components that can render it a failure (and are also very costly to fix). The sleepers have run without the 61-way cables attached since the incidents over the first weekend in February when there were some high profile Class 92 failures in Scotland causing significant delays. There's been no similar issues since. Will let people draw their own conclusions on that one (and note that was with just one loco attached).
This just implies that the jumper standard wasn't really suitable for operation in the first place.
It should not be possible for connecting two locomotives to a jumper system (originally designed for multiple working in the Nightstar era) to cause damage.
Agreed - the 92s were designed to operate TnT in remote multiple (both locos working on full power) on the Nightstar stock and were successfully tested as such. So it seems Brush/Met Camm were able to achieve this in the mid-1990s. Fast forward to 2019/2020 and CAF aren't able to design/produce a similar arrangement that doesn't blow the loco's electronics. Progress...?!
This is very interesting reading. Yes, in normal circumstances the brake pipe is a fail safe system. It is obvious these were not normal circumstances.
I am curious as to what coach information is available from the 92 via the 61 way connector. If there is a 'master' computer located in the 92 it should be possible to have a pressure transducer on each coach that can report the brake pipe pressure, with an electronic brake pressure gauge able to show the rearmost coach's brake pipe pressure. I am also wondering whether there might be a consideration for a 'running brake test button' to temporarily cut the rheostatic braking for the running brake test.
I think the most mind blowing thing for me, is that the technology exists to monitor these systems and flag faults, and it has existed for years. on new stock the lack of monitoring system just seems crazy. At least the coupling procedure has been changed to mitigate circumstances in future.
Assuming the 61-way jumper cable is connected, the information available in the 92 consists of some basic visual/audio alarms on the central window pillar for key issues such as window failures, fire and HABD (Hot Axle Box Detector). There's also a kick-button to over-ride passcom activation if required (note the 10 second delay mentioned in the report) and there's also a handset for comms with the Train Manager.
Detailed coach information is only available on the full TCMS screens in the coaches.
The friction brake on a 92 is pretty powerful too, so not sure disabling the rheo brake for a running brake test would really increase the chances of identifying a fault that much (as the friction brake just comes into play then) - only real way would be to disable the loco's brakes entirely somehow, which is probably not advisable.
There's that many electronics and alarms already going off on modern stock - half the time spuriously, one wonders if it'd actually be better to have less of these and allow the crews to focus on doing the basics properly without all the distractions. Also removes the false sense of security ("it's OK the computer will tell me if there's a problem") and/or the cry wolf issue ("yet another alarm... probably just another computer fault... I'll ignore it...").
The Mk5s are a good example of this - lots of fancy electronics and computerised bits that don't appear to work very well, and then the basic design of crucial components like the Brake Pipe Isolating Cock are somewhat lacking.
