New tube for London stock

Why didn't the Central line problems show up on the prototype 1986TS? Isn't that what they were for? But LU haven't bothered with prototypes since, all done with computer modelling and a pre-production build.

Funny really.

You used to be able to open widows on trains

Now we are recommended to open windows to prevent the spread of any virus

But now trains carry massive extra weight, and use extra electricity, to provide air conditioning because
some people think it is better to spend money on this than have windows that can be opened

I wonder if in view of what has happened, future carriage designs will have to have windows that can be opened

Various points:

1) Normal laminated glass used for train window glazing is heavier than aluminium for equivalent strength. There is work going on in the light rail industry for light weight glazing. This is probably based on the sort of gorilla glass used on mobile phones as a tough outer layer for some sort of plastic core. If/when this is developed, it would have to pass the stringent fire safety standards for tube stock. As has been seen with building cladding, a composite material with a flammable core can produce some very undesirable results in a fire.
2) The car ends on 1992 tube stock were aluminium fabrications and aspects of the fabrication failed necessitating replacement. This was not as a result of body distortion.
3) The 1986 tube stock body ends were made from fibreglass and the connections between these and the bodies were poor. That's why aluminium was specified for the car ends of 1992 tube stock
4) The large curved glass windows were bonded to the body. The preparation of the metal frame and the quality of bonding was absolutely critical to the integrity of the bonding, and many failed leading to the glass falling out. A mitigation was a so-called shoulder test carried out during maintenance. This led to all the windows being replaced by framed windows where the glass is held in place with rubber mouldings and an aluminium trim screwed to the frame.

Sealed windows were introduced with the first Victoria line trains, with indirect ventilation provided instead. They allowed stabling trains to regularly work through the acid wash machine on their way to depot. On other lines car washing was labour intensive, with someone walking through each train to close all windows, before a stabled train could be worked through the wash machine to the depot shunting neck, and then back to its stabling road. This limited the number of trains that could be washed each day.

Is there a need for windows on Tube stock?

I'd prefer windows, but I wonder why they don't have them in most lifts.

What about the Waterloo & City?

I really don't like closed-in lifts; they are just so uninteresting.
With gates, you could see everything going on. Travelling in the lift wasn't just routine; it was an education.
Just what a wide-eyed kid needed, an outlook on the workings of the world!

Bus operators manage to cover windows with adverts, which prevent seeing in but not passengers seeing out. There could be a fire risk underground, perhaps?

Not wishing to take this off course, but people of a certain age may recall "visions of the future" on TV or in the cinema, where any form of transport, on land sea or air, had windows, or was a transparent bubble, even if it passed along underground tunnels at vast speed. There must be something in the human psyche that expects to be able to see, as well as sense, movement. I'm sure there's a way of fitting advertising to tunnel walls that can be read as a train passes through, something like a "flick book" combined with those oddly shaped ads on sports fields that look perfectly rectangular when seen on TV.

In 2005 I took a train from Frankfurt airport into the centre of the city. On the tunnel walls there was an advert (for some sportswear company I think) that kept pace with the train (it was an animated running figure running alongside each window). Based on the advert style I'd guess this was using LED technology but I don't know for certain.

Are we in danger of going 'off piste' when we are supposed to be discussing train stock here?

I am convinced that any advertising revenue gained by advertising inside trains where we would expect to find windows, will be wiped out with more revenue lost than gained,
because many people will not travel in trains without windows. Many women will feel unsafe, and in view of a recent news story, - - - - - Do you really want a backlash from women travellers?,

How can you possibly say "For something like the Waterloo & City Line"?

There isn't anything else in London "like" the Waterloo & City Line.

That's the point, we're talking about new stock for 'ordinary lines', not the one exception that proves the rule.
So you would design and build new, separate, non-interchangeable stock for the W&C? Because you won't be able to use it anywhere else.

I know its not exactly the best of views, but passengers are used to seeing the passing tunnel walls and prefer this to no windows!

Also, as has been said already, windows on trains are useful at stations - not just to know where you are (which admittedly can be found out from electronic information inside the train, if it is working!) but for orientation such as seeing the platform exit, where people are waiting on the platform, and so much more.