Glass and railways: how to specify train glass
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What kinds of glass are used for train windows, windscreens and similar applications? Find out in our guide.
Most industries rely on glass in some way. However, the world of glass fabrication is so multifaceted that each industry uses different products in different ways.
The train and railway industries are no exception. Glass is used for train windows, windscreens, display screens and more.
Not just any glass will do, however. The most important distinction in this context is between safety glass and non-safety glass.
Both are umbrella terms that cover different products. But the key difference is the way the glass breaks.
Take the glass that glasses and tumblers are made of. If you drop a wine glass, it will shatter. Or take a pane of annealed glass, the kind that was predominantly used for domestic windows in the 20th century. Throw a brick at it and it will shatter into harmful shards.
In the industry, these kinds of glass don't count as safety glass. They wouldn't cut it, for instance, as the glass for an elevator or a balcony – or a train window.
No, these applications – and pretty much every application in the train industry – require something altogether tougher. Enter safety glass.
What is safety glass and why is it used for trains?
Safety glass covers different types of glass. But all these types have one thing in common: when they're subjected to force, they don't break into shards.
The two most common in the train industry are toughened and laminated glass. Above all else, these are designed to be strong and impact-resistant.
After all, train windows are vulnerable to all sorts of impacts: from branches to gravel, from birds to unwanted projectiles. If anything but safety glass is used, the safety of passengers – and on freight trains, stock – is put in danger.
Toughened glass (also known as tempered glass) is a common choice for train manufacturers. It's heated at a high temperature and then cooled rapidly. This quenching process excites the molecules in such a way that the glass sets with a higher tensile strength. It also means the glass won't shatter into jagged shards.
In the event of a collision, toughened glass will break into lots of small, harmless pieces. This keeps passengers and stock safe, as well as limiting the damage done to the train interior.
Sometimes, even toughened glass isn't tough enough. This is often the case, for instance, in high-speed trains.
For these,
laminated glass is used. This type of glass is created by bonding a plastic interlayer between two panes of glass.
If you've ever walked past a car with a broken windscreen, you'll have seen laminated glass. Unlike toughened glass, it's shatterproof. If you hit it with enough force, cracks like a spider's web appear across the surface but the glass retains its structural stability.
These types of safety glass, then, are industry-standard for train windows and windscreens. Sometimes, however, thermoplastics like polycarbonate are used – and sometimes chemically strengthened glass.
What is chemically strengthened glass?
Chemically strengthened glass is a super-tough glass that's typically somewhere between six and eight times stronger than float glass. When it breaks, however, it shatters into long, pointed splinters. This means it doesn't qualify as safety glass.
Its awesome toughness, however, makes it a popular choice for railways nonetheless. Often trademarked as Gorilla glass, it's strengthened with chemicals after production.
In the train and railway industries, chemically strengthened glass is often used for the side windows of bullet trains.
Smart glass windows
The glass fabrication industry is changing all the time. One of the most exciting recent advancements is
smart glass.
This is a type of glass that can be switched from transparent to opaque at the touch of a button. It's used in all sorts of domestic and commercial settings – from office partitions to medical privacy screens, from shower doors to car sunroofs.
The train industry is always innovating, too. So, it's no surprise that some train manufacturers have embraced the thermal, visual and acoustic enhancements that smart glass can provide.
Most trains, of course, still use simple blinds. But some are embracing smart glass, allowing passengers to dim the glass itself. Aside from enabling passengers to control the light coming into the compartment, it also gives them privacy when the train is stationary.
Some are even multi-zone windows. This technology lets you dim parts of the window but not others. It's a level of comfort and control that's sure to catch on as manufacturers become more aware of smart glass and its potential.
At ToughGlaze, we have our own range of
toughened smart glass that can be used for train windows and a plethora of other applications.
Panoramic trains
On some trains, the windows curve onto the roof, providing panoramic views. These use curved glass: glass that's fired in a mould.
Perhaps the most famous panoramic trains are in Switzerland. Take the Bernina Express. This is the highest train route in Europe, offering unobstructed views of the Alpine peaks between Chur and Tirano.
Some panoramic trains even have a glass aperture in the roof. This skyward view is available to passengers taking the Luzern Interlaken Express between Lucerne and Interlaken in Switzerland.
Outside of Switzerland, the most famous panoramic train is probably the Rocky Mountaineer in Western Canada. This covers more than 600 miles between Vancouver and Jasper.
Its oversized, curved windows cover almost the whole of the roof. Passengers can swivel and recline in their seats to maximise their enjoyment of the spectacular views.
The bottom line
When installing glass on trains, safety is paramount. For this reason, safety glass products like toughened and laminated glass are frequently used. Both of these can be "smart" or "switchable", changing from transparent to opaque at the switch of a button.
Sometimes, however, an especially tough non-safety glass like chemically strengthened glass can be used instead of toughened or laminated panels.
Are you looking for train glass? As one of the UK's most trusted glass processors, ToughGlaze offers
toughened,
laminated and
smart glass panels cut to your precise requirements.
Contact our experts today for a quick, competitive quote.
