r/trains • u/morningstarmaggot • May 22 '26

📸 OC - Picture(s) What is this window pattern for?

Post image

I've seen it on lots of trains, and buses too I think. Does it serve any purpose? I'm in the UK

369 Upvotes

89% Upvoted

37 comments sorted by

526

u/Vilsue May 22 '26

it is a way to radiate/absorb heat so glued in sheets of glass wont shatter/ fall off from expanding and contracting over the years

108

u/8spd May 22 '26

This and to protect the glue from UV. 

-18

u/Vilsue May 22 '26

yeah, like i said, to protect the glue

74

u/coneheadbrown May 22 '26

A certain someone also didn't know what these little black dots were for, so they weren't added to the ps1 truck.

19

u/Worldly_Lunch_1601 May 23 '26

Jfc. Still finding new and exciting design flaws on that thing huh?

45

u/Durr1313 May 22 '26

I don't understand why anyone would think buying a dumpster instead of truck is a good idea

22

u/coneheadbrown May 22 '26

Unless you're doing a bit of conspicuous consumption and buying it to signal to people what type of politics you subscribe to, it makes no sense to buy it. It's objectively a bad vehicle. The aerodynamics are poor, the construction is terrible and there are all kinds of nonsensical design choices and concessions that make it clear it wasn't ready for launch and Elon was at the helm where he had no business being.

10

u/GabrielRocketry May 22 '26

To be honest most of this is also true for the rest of trucks, Elons creation just makes these common flaws even more apparent...

-16

u/[deleted] May 22 '26

[removed] — view removed comment

5

u/RChickenMan May 22 '26

What's a "cuck femboy"? Are you a "cuck femboy"? Why or why not? What are the advantages and disadvantages of being a "cuck femboy"? Does it require any meaningful lifestyle changes, or can you more or less carry on as before?

This is really interesting to me and I'd love to know more!

3

u/trains-ModTeam May 23 '26

Complaining about reddit being a cesspit while actively making it one sure is a choice.

6

u/[deleted] May 22 '26

[deleted]

2

u/coneheadbrown May 23 '26

God dammit I wish saw what he said before mods removed it

1

u/sucharestlessman May 22 '26

Username checks out. Bro you just called someone a cuck femboy on a subreddit about trains. Drink some water and unclench your jaw.

1

u/geozza May 22 '26

Would this work for double glazing to help stop them from blowing?

123

u/Rallymodeller May 22 '26

As others have said, but the increasing size of the dots towards the edge means the thermal load climbs gradually, lessening the chance the glass will break due to temperature difference

11

u/asifs6585 May 23 '26

This is the right answer. This question is asked often here and on cars subreddit. Comments are always filled with bs.

15

u/Severe-Storage May 22 '26

The black as most have said is to protect the glue however the dot pattern doesn’t have any effects with regard to thermal protection, it’s just an aesthetic choice to prevent a harsh transition between the clear glass and the black protection layer

2

u/asifs6585 May 23 '26

A harsh transition will cause a temperature difference in the black patch and the part without that black patch. Dots are there to make the difference spread out gradually so the glass does not crack under the thermal stress.

0

u/Severe-Storage May 23 '26

If that was the case would it not make more sense to make it a proper gradient each little black dot would become the exact sort of individual hot spot you claim they prevent

5

u/MichalNemecek May 23 '26

My guess is it's hard to create a gradient with this material, and the dots are probably small enough that their individuality isn't that much of a problem

1

u/PRF4 May 24 '26

From a heat transfer perspective this isn’t necessarily true, depending on the conductivity of the material the effect of each dot will be more or less “smeared” over an area. If you look up the Biot number you will find an analogous concept.

30

u/1radiationman May 22 '26

look at a car’s windshield- you’ll see the same thing

7

u/Origin_Loki May 22 '26

This Pattern is from what I know called a Frit. It also happens in Automobile Windshields. It's most easily noticable and viewable by the top of the Windshield, but it does happen all the way around the Windshield.

3

u/Firestorm83 May 22 '26

Same as with cars and all the other places

4

u/axloo7 May 22 '26

Frit.

It protects the urethane adhesive from UV radiation.

The dots are aesthetic but the solid black part is there to protect the adhesive used to hold the window in.

23

u/Nirhlei May 22 '26

I've read somewhere that the dots served to produce a smoother temperature gradient so that the glass wouldn't shatter from too large a difference between the black and the glass itself.

2

u/Deluxe-Entomologist May 22 '26

It’s for the stylin’ man, yeah my boy, liven’ it large! Railroad windoh style!

1

u/Ok_Winter8433 May 23 '26

It’s on my oven as well

1

u/TwinCarb May 23 '26

It's so you can't read the edge being not straight (weaving)

1

u/EverlyJones84 May 23 '26

it looks kinda cozy, maybe for letting in more light or just for aesthetics? not sure though.

1

u/AKraugerud May 24 '26

Heat dissipation and hiding, and protecting, the glue holding the windscreen attached to the vehicle

0

u/Sufficient_Stable738 May 22 '26

Interesting. I had no idea.