Recent content by edwin_m

It was related to the shape of the electromagnetic field produced by the loops - known as "side lobes". This didn't matter at normal speeds but when they tried to use it for buffer stops (which it was never designed for) it wasn't possible to get the timing accurate enough.

Mk2 aircons and Mk3s get their power for lighting (and everything else) from the train supply which is jumpered through from the locomotive or power car. I assume they also have a battery for emergency lighting when no supply is available.

Data centres are static targets and Ukraine knows where they are - apparently Yandex only just wiped their co-ordinates from the Web. So Ukraine can carry on hitting them, although without near-real-time updates on locations of air defences fewer drones will get through. Ironically for Trump...

Can the 222s keep to time on 4? Are 221s also routinely running around on 4? They are older units and these particular ones have spent time out of use, which usually isn't good for reliability. They can't multiple with 222s and if either unit fails it's virtually impossible EMR will have two...

They may go back to Central Rivers for servicing. This avoids some of the engineering issues - they have totally different bogies from 222s for example - and I imagine Etches Park has its hands full already without taking on a new class. Also a risk that they might not meet 222 timings, as the...

But it's an interesting discussion point. Should management have agreed to make the informal start/finish times official to avoid the distraction of copying the records?

There is the option of digging out the surface and leaving the rails in place with a temporary speed restriction, and replacing a section of rail each night. But that may not be possible depending on the trackform. Another option is temporary crossovers, but they would be difficult or impossible...

In fact doing the paperwork contributed to the accident by distracting the signallers.

Abermule is a good example of a chain of human errors, any one of which would have prevented the accident if it hadn't happened. The OP has clarified their field is healthcare, where there are relatively few engineered safegards so one with a strong human factors content is probably better. It...

It is also structural. Note the gap between the top of the abutment and the bottom of the span, so the "pilaster" part is actually supporting the beam. Most likely this concrete span replaced an older one that sat on the edges of the abutment.

There's a shorter version here that includes all the key facts and informed speculation about the incident itself, but doesn't attempt to go into the politics:

I sort of recall a separation between units (158s at Glasgow Queen Street?) that led to a rule that after coupling Sprinters the driver should attempt to drive one away with the brakes applied on the other. Presumably this can only be done after physical coupling but before the control circuits...

There was a keyhole but also two buttons.

The change to LED aspects does of course reduce ownership costs for signals, hence also the benefit of removing them.

There were separate buttons for on and off, but these only controlled the coach they were operated in. The key switch controlled the whole train. Mk1and all mk2 had these on a cast metal panel and Mk3 had a steel plate.