Through the Windshield Together
How laminated automobile safety glass was discovered—by accident
One day in 1903 while working in his Paris lab, chemist Edouard Benedictus climbed a rickety ladder to fetch some needed elements off a high cabinet. In the process, he bumped a shelf lined with tipsy glass flasks, sending one tumbling to the floor. Predictably, the flask shattered. But much to Benedictus’ astonishment as he peered down from his perch the pieces didn’t scatter across the floor. Instead, they clung together, roughly retaining the original hollowed shape of the container.
Intrigued, Benedictus showed the broken flask to his assistant. The man informed his boss that the container recently held a solution of cellulose nitrate, a kind of clear liquid plastic. The pair deduced the water in the solution had evaporated, leaving a thin transparent film covering the inner walls of the flask. Because the container looked empty and unused, it had simply been replaced on the shelf without being washed. Entirely by chance, Benedictus had discovered safety glass.
In another of the many serendipitous coincidences with which history is filled, that same week a Paris newspaper ran an article about a new concern arising around the city — collisions involving motor carriages. Automobiles were new to Paris in 1903, and the intersection of overly enthusiastic drivers and unwary pedestrians was already proving disastrous. Upon reading the account of accidents involving automobiles, Benedictus was struck by one detail in particular — many of the most serious injuries involved drivers being horribly cut by the shattered plate glass of their windshields.
Benedictus had his eureka moment. As he would record in his diary: “Suddenly there appeared before my eyes an image of the broken flask. I leapt up, dashed to my laboratory, and concentrated on the practical possibilities of my idea.”
Benedictus spent the next 24 consecutive hours at work in his lab, feverishly coating one glass flask after another with various mixtures of clear plastic then smashing them around the room. Had any of Benedictus’ assistants walked in on their boss at the time, they would have likely concluded the man had gone daft from inhaling noxious chemical fumes. “By the following evening,” Benedictus continued in his entry, “I had produced my first piece of Triplex (safety glass) — full of promise for the future.”
Benedictus spent years improving his creation, adding a layer of gelatin to the film to bind two panes of glass together for greater strength. He finally received a patent for his invention in 1910.
Unfortunately, early automakers didn’t share Benedictus’ enthusiasm for his new idea despite the fact they had already begun producing models with fully enclosed passenger compartments. This meant they were surrounding occupants with glass windows that, in an accident, instantly transformed into a whirlwind of razor-sharp shards.
The reality was that safety glass was expensive and difficult to produce in mass quantities. To make cars more affordable to a wider market, automakers were desperately seeking ways to lower the price of cars, not raise them. Moreover, the prevailing attitude was that the primary responsibility for the safety of automobile occupants rested with drivers, not manufacturers. The role of carmakers was to help drivers avoid accidents with improvements like better brakes and handling. But they felt no obligation to help minimize injuries should drivers become involved in crashes.
So, for more than two decades after Eduouard Benedictus first stumbled upon its invention, safety glass was largely ignored. Meanwhile, automobile owners continued to shell out money for standard glass panes every time a stone got kicked up from an unpaved road, and occupants continued to suffer horrible injuries from shattered glass in accidents. It became so common for the throats of drivers to be fatally slashed after being thrust headfirst through their windshields that the phenomenon earned its own nickname: “wearing a glass necklace.”
It took two catalysts for safety glass to finally get the attention of automakers. The first was a world war — WWI, to be specific. Shortly after poison gas made its debut on the battlefields of Europe, both sides attempted to protect their trench-bound troops from its lethal effects. Unfortunately, early gas masks weren’t up to the challenge. Unable to withstand the rough conditions of combat, the standard glass lenses used in the masks often cracked, creating openings that rendered them useless. But mask manufacturers soon discovered that laminated safety glass was an ideal substitute. Having earned its stripes in combat, safety glass was soon adopted for other wide-scale applications that required a more durable type of glass.
The second impetus for carmakers to reconsider safety glass was a wave of lawsuits brought by motorists injured by glass in collisions. Remarkably, the most notable of these cases involved an injured driver by the name of Pane. That’s right — the question of whether automakers should be required to install safety glass in automobiles hinged on the 1917 case of Pane vs. Ford. Ultimately, the court determined Pane’s reckless driving was the cause of his own injuries and Ford won the case. Other automakers were exonerated in similar cases.
Despite winning lawsuits, carmakers were losing in the court of public opinion. By 1923, it was estimated that half of all injuries sustained in car accidents were caused by shattered or flying glass. The argument used by automakers — that they were holding down costs to make cars affordable for middle-class buyers — was proving to be, like their windows, a flimsy defense for continuing to use plate glass when a stronger, safer alternative was available.
It took a few years, but eventually Henry Ford would be the first to relent. By some accounts, Ford’s change of heart was the result of witnessing a close friend horribly maimed by a plate glass windshield in an accident during a test drive of his new Model A. It also didn’t hurt that new production techniques were narrowing the price gap between making standard plate glass and safety glass.
As the demand for vehicles with fully enclosed passenger compartments continued to soar, Ford began producing its own safety glass at the company’s colossal Rouge River plant. Working in partnership with a British glass manufacturer, Ford perfected a process for producing laminated safety glass on a massive scale. Ford called its variation of safety glass “Indestructo Glass” and incorporated its use in the windshield of the company’s much-anticipated Model A, which premiered in 1927. Within years, the newer, safer glass became standard in all Ford automobiles.
In reality, “Indestructo Glass” didn’t live up to its name. The glass still shattered when stressed or impacted in accidents. But its fragility actually worked to motorists’ advantage. When occupants were hurled into a windshield during a collision, the thin cellulose layer inside the glass stretched to provide a sort of cushion effect, not unlike an airbag in reverse. More importantly, the elastic film prevented occupants from penetrating the glass and coming to rest on the razor-sharp bottom edge, the cause of the worst injuries in accidents.
The greatest contribution of Indestructo Glass to car safety, though, was that it set a new industry standard. Ford was by far the leading automaker of the day and had featured laminated safety glass in its flagship vehicle. Competing car companies felt compelled to follow suit. By the mid-1930s, nearly all cars produced in America were equipped with windshields made of laminated safety glass, greatly improving safety for drivers and passengers alike.
Still, it had taken almost 25 years for the auto industry to embrace an innovation that could have prevented the horrific maiming and deaths of thousands of motorists. Even then, automakers only used safety glass for windshields. They continued to use cheaper plate glass in side and rear windows, putting vehicle occupants at unnecessary risk, until tempered glass was developed in the late 1930s. In stubbornly refusing to incorporate safety glass in cars for so long, automakers had set another standard for their industry that would last for decades: whenever safety concerns collided with sales goals, safety would always lose.
