Bletchleyite
Veteran Member
Also the link you've provided says the survival rate is so low because of people suffering cardiac arrests in the US not getting CPR quite often due to bystanders not knowing what to do. So you've actually provided evidence that a driver (or passenger) suffering a cardiac arrest is more likely to survive a heart attack if the guard knows CPR.
There are a lot of misconceptions out there about what CPR is for. CPR generally will not cause someone's heart/breathing to restart or correct an incorrect heart rhythm, with a few exceptions e.g. drowning where it can force water out. You need an AED to correct an incorrect heart rhythm or (in very few cases) to restart it.
What CPR does is to keep oxygen going into the body and blood moving around so the brain does not die. On that basis it's really important that as many people as possible on that train, certainly the driver and guard[1], stuck in a snowdrift/landslip on the S&C in high winds[2] can do it, because it's utterly physically exhausting (as much so as going for a run) and generally must be carried on until help arrives.
[1] I know they need to protect the train/line as a primary responsibility, but once that's done.
[2] That's my entirely plausible scenario for rescue potentially being an hour or more away on a train.