Jacobite 2025

Always assumed that pressure ventilation is a result of a train moving ? not electric fan driven...

 

Short summary: aircon chills the air in the space and keeps it there. Pressure ventilation forces air changes.

Given this isn't "the National Building Services" website, probably this is a blind alley, but here is a version from a third party
https://www.airmatic.co.uk/knowledg...nce-between-ventilation-and-air-conditioning/
(It says ventilation means getting the air from outside, aircon is treating the air inside).
This chimes with my understanding. The xp64 stock was pressure-ventilated not aircon, mkIII are aircon). Of course if you have working aircom, opening any window is a bad idea as you risk dumping the cold air out and letting warm air in.
At the time, it feels like a good idea as the breeze feels cooler, but over time, it's better to let the air cool. Of course, it's very hard to notice that which is why people block doors open etc.

I suspect the "natural" ventilation of a moving train with open windows could be called pressure ventilation, but generally wouldn't be as it's a by-product rather than a planned actiom

 

Speak for yourself. In the present weather it's bad enough being in a train with opening windows and no aircon. People who were stuck on trains recently with neither opening windows nor working aircon are reported to have forced doors open, and I for one don't blame them.

 

What exactly does that achieve?

 

Last weekend, potentially the difference between a medical emergency and not. It's not relevant to this thread, but the railway industry has for at least 15 years had a significant problem with managing train failures and the potential for passengers to self-evacuate, which has featured in more than one RAIB report.

 

Has it actually avoided a medical emergency? And if so, why wasn't the emergency handle used?
How many self-evacuations were actually justified? IIRC the one on the tube recently was more becuase of a failure to understand what was going on.
Are they that more common? When the trains got frozen up on the third rail in the late 80s early 90s my father tells me of people opening the doors and climbing onto the track. Which again was utterly counter-productive as everything needed to be stopped in order to get them off the tracks...

 

One of the Jacobites is now formed up with 5229, 5453, and 5487 (all pressure-ventilated) as the 2nd, 4th, and 6th vehicles of the formation.

 

The trains were stuck in full sun on a viaduct - that's why self-evacuation happened.

As for absolute frequency, it's hard to say - but your father's story reinforces my view that the industry have failed dismally to get their act together about managing timely evacuations in response to incidents.

 

My father's story is over 30 years ago, so suggests it's not a recent thing, and made the wait longer for everyone and more risky for those who got out.

Being cooked in a train is not nice, but is it the fault of the railway company if they keep people in the safer place? The time taken to sort it out is clearly poor, but that to my mind is a slightly different question

 

They are separate questions, but the linkage is the willingness of people to remain cooped up. The response plans need to consider the passengers aboard as independent actors, not as mere passive vehicles for the decisions of controllers.