D Stock ventilation system

[Deleted]

Hello all!

I've been curious about the two ventilation vents inside the D stock. I could see they re-did the vents itself on the refurb as I can see the shiny foil lining inside. However, I have never felt any ventilation coming through these things.

Are these vents supposed to pull air from the carriage and blast it outside into the tunnel or is it the opposite? I heard an unusual noise from the ceiling of a refurb D Stock once but I still couldn't feel any air.

[Oracle]

The original 73TS units had ceiling fans when delivered I remember but when new they made a lot of noise but seemed to do b.a.

[TMBA]

This one goes back a few years for me, anyway the Axial fans that are at the ends of the car on the D stock are meant to run when the train goes of juice they are Battery fed from the UNDM car, they are meant to run as an emergency measure.

The fans that run along the whole of the carriage are suppose to run all the time when the thermostat in the second car tells them to, but all things being the way they are the thermostat never works properly and it normally tells the heaters to come on instead even at 25 degrees

Unfortunately when the D stock first came to being on the district in 79/80 they never had any drop down windows to vent the cars and peeps were passing out all the time so the were sent back to M/C and had the drop downs installed, BUT the wiring that controls the Axial fans and the normal fans is around the wrong way so hence you probably hear more of the Axial fans then the normal ones.

Remember though that the Axial fans run purely off the batteries so under normal running conditions you could in effect end up with flat batteries real quick if the juice goes off.

Ive put many a memo into certain managers to no avail and I still carry a certain handout round with me from a certain well known Traffic Manager that clearly states that the fans are wired up wrong.

Can anybody add to this for me or correct anything I might have got wrong?

[Colin]

Being no expert on stock (just ask Solidbond ;D), all I would add is:
The fans which run off the thermostat will only work if the "Heat/Vent on" button is pressed. More often than not in the summer because [as mentioned] most trains don't work as they should, the system is not actually turned on.

[solidbond]

The major problem with the D stock heat & vent is, as hinted at by TMBA, to do with the opening windows. When the D stock were built there were no opening windows, except in the end car doors. When the opening windows were added, it improved ventilation, however one of the problems was that the thermostat for each car was located in the middle of the car - right next to the opening window Hence the problems of the heaters being on in the summer You've probably noticed the metal cylinder just next to the windows by the bay seats on a D stock? Well that is the thermostat. What happens is that passengers get on in the summer, and automatically open the window for ventilation. Trouble is, the air that comes in is (comparatively) cold, so the thermostat decides that the heating should be on Only solution is to switch the heat & vent off
Just to add to TMBAs comments, the Axial fans have mostly been disconnected, by having the fuses removed, due to the problems that TMBA states. If anyone wants further info on how the vent SHOULD have worked from build, let me know and I'll get a copy of the original info.
Note that with the refurbs the thermostat has been relocated to the ceiling area so the above problems shouldn't happen, and so far so good. Thus you may hear the ventilation fans finally start doing their stuff ;D ;D

[TMBA]

After nearly 30 odd years service and refurbishment it would be nice to think they might have got it right now wouldn't you.

[Deleted]

on some deep tube stock you can lower the car end door window for ventilation. Why not the side windows or other windows as well as this?

[Colin]

rob said:

on some deep tube stock you can lower the car end door window for ventilation.

That is the same on all LUL passenger stock, not just deep tube.

rob said:

Why not the side windows or other windows as well as this?

D stock has 'hopper style openings' along the sides - though i'm not 100% sure, I think you'll find all other stocks have no side opening windows.

[c5]

colin said:

rob said:

on some deep tube stock you can lower the car end door window for ventilation.

That is the same on all LUL passenger stock, not just deep tube.

rob said:

Why not the side windows or other windows as well as this?

D stock has 'hopper style openings' along the sides - though i'm not 100% sure, I think you'll find all other stocks have no side opening windows.

The A Stock is the only other oe with "hopper" windows, but only where there is not door accomadation.

[Deleted]

Just like to post a huge thanks to those who replied. Very insightful and technical!