[BoneCollector]

Indian Railways has introduced smart windows on Rajdhani Express first AC coaches of Howrah Rajdhani on trial basis. These can be turned opaque on switching off a switch and will become transparent once switch is turned on. It is based on Polymer Dispersed Liquid Crystal technology also known as Smart Glasses.

Link 1

Link 2

This has been introduced because of removal of curtains in COVID times.


I was wondering that if it can be introduced on cars too.

[saikarthik]

Originally Posted by BoneCollector

I was wondering that if it can be introduced on cars too.

It can be on public transport vehicles like busses and shuttles for passenger windows but not for cars.

Main reasons:
1. Cars run on roads where we are affected by the blind spots already, and the driver needs to look at the ORVM and IRVM, so eliminates the usage when vehicle is running. Trains run on track with no need to worry about the blind spots.

2. Costlier option when there are shades/blinds available.

3. Safety concern - These glasses work on application of electric current and if there is any electronic failure, wire cut or fuse blow, they go translucent and can cause an accident. Usually they are designed keeping this point in mind - Be transparent when electricity is removed still I won't trust these.

4. Replacement cost on damage might be dearly. Not to forget the crash safety considerations while design.

[nagr22]

Originally Posted by BoneCollector

These can be turned opaque on switching off a switch and will become transparent once switch is turned on. It is based on Polymer Dispersed Liquid Crystal technology

I was wondering that if it can be introduced on cars too.

This is same as the electrochromatic windows seen on Boeing 787 Dreamliner jets. There it also has multiple levels of opacity/transparency. This is a good initiative and will save Indian railways the cost associated with cleaning the window curtains (not sure if they were indeed cleaning them before).

As others mentioned, it's a safety issue in cars so it will most likely be not allowed. However, it may be allowed on the rear windows as that won't affect visibility and tinted rear windows are pretty much standard in European countries.

[Dr.AD]

These windows were first used in Boeing 787 Dreamliner, and they are very cool. I loved those during my flights in 787. Those windows can be turned from totally clear to very dark, and at any shade in-between, by rotating a knob.

Here is a good article: https://simpleflying.com/boeing-787-dimmable-windows/

For cars, apart from legalities, they would be very expensive.

P.S. Saw the above post after I typed mine and posted. The above post have covered it well. Sorry for the repetition.

[gkveda]

Originally Posted by BoneCollector

I was wondering that if it can be introduced on cars too.

Forget smart windows on car, with full opaque to full transparent conversion. I will be overwhelmed if the government allow simple sun film with 60% to 70% transparency.

I don't expect any citizen friendly decisions by supreme court in this regard. Inefficiency of police department to curb crimes inside car has resulted in this decision and all citizens are suffering because of this decision.

Now, introducing this smart windows, in no way reduces the crimes inside cars. So, no hope of getting permission by supreme court.

[GTO]

Mod Note: Thread moved to the CV section which is where we usually discuss trains. Thanks for sharing!

[itwasntme]

McLaren, Tesla and other luxury convertible makers are adding / have already added SPD glass as an option.

https://anthonyvolkglass.com/blog/wi...chnology-2019/

[vinu_h]

Would love to have this at home & do away with curtains + rods . Found a neat article on this subject.

[libranof1987]

Very interesting that Indian Railways are looking at technology to solve problems, rather fix something that isn't even broken in this place.

Incidentally, I just recently read on something similar. Some South Korean trains have automatically fogging windows, to aid privacy when the trains pass through residential areas.

Here’s a cool privacy feature on the new monorail train in Daegu, South Korea; windows that automatically fog when passing apartments that are close to the train. The technology is known as Smart glass and the glazing occurs when the window’s light transmission properties are altered through the application of voltage, light or heat to the surface.

https://twistedsifter.com/2016/07/wi...by-apartments/

[railfanwithk750]

Nice concept but :

• Will the switching still work when there are minor chips/dents to the glass? Most of the window glasses have chips and minor cracks from stone hits, debris and so on. The smart glass being just another variation of an LCD, is prone to stress and hope it doesn't end up looking like a battered mobile screen with streaks of transparency in the opaque layer.
  
• How will it hold up with the aam-junta kind of misuse (curious and excited passengers messing around, kids repeatedly flipping the switches on/off, suitcases hitting the panes and so on)?
  
• Unlike a traditional curtain, there is no darkening achieved from the smart glass. Curtains were traditionally used to further darken the window if someone wanted an afternoon nap!
  
• What if the person sitting opposite wants to keep looking out of the window, but I want to block my privacy? This was doable by partially closing the curtain, now there will be more arguments to bear!

[gusfring]

Originally Posted by railfanwithk750

Nice concept but :

• Will the switching still work when there are minor chips/dents to the glass? Most of the window glasses have chips and minor cracks from stone hits, debris and so on. The smart glass being just another variation of an LCD, is prone to stress and hope it doesn't end up looking like a battered mobile screen with streaks of transparency in the opaque layer.
  
• How will it hold up with the aam-junta kind of misuse (curious and excited passengers messing around, kids repeatedly flipping the switches on/off, suitcases hitting the panes and so on)?
  
• Unlike a traditional curtain, there is no darkening achieved from the smart glass. Curtains were traditionally used to further darken the window if someone wanted an afternoon nap!
  
• What if the person sitting opposite wants to keep looking out of the window, but I want to block my privacy? This was doable by partially closing the curtain, now there will be more arguments to bear!

The first one... Well, we will know in a couple years maybe? Don't know how expensive it is, but a question here : are they retrofitting this tech onto the glass? Or should it be fitted in right during manufacturing?

Indian Railways isn't new to misuse by curious passengers (Tejas express knows this well). Thankfully they aren't something that can be taken home like those headphones. In fact IR would be better off not posting any signage for the same (sounds cruel, yeah, but atleast there won't be misuse). They've made it as a normal switch, and the majority would probably just assume it is another fan or light switch

The last 2 points are... unsolvable, unless they do two glasses for every of the single ones, and bring curtains back. Kinda defeats the purpose, but I guess it's time to learn to live in the new (soon to be) normal in AC compartments

[H0RSEPOWER]

It is surely an innovative touch. But the deletion of curtains & the opaque glass not being a dark one would make the passengers compromise with their afternoon nap
And as mentioned in the earlier comment, in this case, it would be better to have two separate window panes for two adjacent seats instead of one wide glass pane in order to make it parallel operational by both.

[iamahunter]

This is something brilliant and definitely not safe for cars. Probably more dangerous than the tinted glasses for side windows.

However, now-d-days when we Indians are so obsessed with sunroofs, this can be the best thing to get up-top.

[aashishnb]

Originally Posted by Dr.AD

These windows were first used in Boeing 787 Dreamliner, and they are very cool. I loved those during my flights in 787. Those windows can be turned from totally clear to very dark, and at any shade in-between, by rotating a knob.

Here is a good article: https://simpleflying.com/boeing-787-dimmable-windows/

For cars, apart from legalities, they would be very expensive.

P.S. Saw the above post after I typed mine and posted. The above post have covered it well. Sorry for the repetition.

Originally Posted by vinu_h

Would love to have this at home & do away with curtains + rods . Found a neat article on this subject.

I saw this technology a little more than a decade ago for user in the bathroom glass (one between the room and the bathroom) of a hotel room - replacing the curtains. Even the hotel chain did not really go ahead with wide implementation due to costs.

From what little I understand, this is 2 pieces of glass with some chemical on between which changes colour when current is passed. It is a fragile and expensive setup and may not be that beneficial. Any problem and one has to replace the entire pane.

[Holyghost]

Back in 2006, I used to work in a special access controlled room and the rear wall and the glass door was made of this switchable glasses. Since we were working for the legal counsels and had to review extremely sensitive documents, it was mandatory to keep the glass opaque while working, and leave it clear while exiting the room. It was fun since no one else had access to this room and no one could see what we were doing once the glasses were opaque. Even my Manager had to knock and wait outside until we open the door from inside.

The technology is simple and is similar to the LCD screens of our calculators. When you pass a current, the liquid crystals changes the orientation blocking the light passing through them.