An Entertaining & Informative Vintage Automobile Internet Magazine

Look Ma No Hands: Packard Floats on Tempered Glass

Tempered glass is reported to have been first discovered circa-1902 in France. The Pittsburgh Glass Company (PPG) later developed its own “Herculite” brand of tempered glass and introduced it to the public in 1938. Unlike plate glass, tempered glass when broken transforms into small crystal-like pieces that are much less likely to cut or impale people seriously during an accident. This new form of glass was used in automobile side and rear windows.

The other type of glass for modern automotive use is laminated safety glass that is made up of a piece of clear plastic bonded in the middle to two sheets of glass. This form of glass was first introduced for use in car and truck windshields with the new Model “A” Ford in 1928 and is generally considered to be its first use in the US.

The lead image and the expandable version of it below contains a mid-to-late 1930s Packard sedan and five men carefully placed on two pieces of “Herculite” glass positioned by PPG on wood blocks to demonstrate the strength and flexibility of it’s product before it reaches the breaking point. If you are wondering how the company engineers may have put the Packard on the glass for the promotional photo, the building is equipped with a traveling bridge crane and a hoist, visible at the top left of the photo.

PPG later introduced “Herculite”curved glass for use in automotive side and rear photos.

Tell us what you find of interest in these photographs courtesy of the University of Pittsburgh Library.


19 responses to “Look Ma No Hands: Packard Floats on Tempered Glass

  1. I figured the only way that Packard got there was an overhead hoist. Still, that’s an AMAZING amount of weight for that glass!

  2. Based on the license plate, I think the image is probably 1938. From 1937-1942, Pennsylvania alternated between a blue state outline with yellow letters and a yellow outline with blue letters (there was no 1943 plate due to metal rationing, and 1944 was the yellow-on-blue that 1943 should have been, reversing the pattern of colors by year). Since that plate has a yellow outline with blue letters, it’s either 1938, 1940, or 1942. I can’t imagine this being a wartime promotional photo, so I’d eliminate 1942, and ’38’s more likely because of that being the year PPG introduced Herculite.

    The fluted bumper suggests a Packard Eight, but that third nubbin on the bumper is making me doubt my assessment.

  3. Love those old material strength demonstrations, especially when they include a favorite car. Handsome 120 with optional center grille guard and ‘donut’ chaser hood ornament.

  4. Photo may have been taken in the PPG plant in Ford City, Pa. I recall employees talking about manufacturing Herculite. Many of the buildings are still standing.

  5. The “fence” between the Packard and the building looks like it could actually be wooden shipping or storage crates aligned lengthwise with content tags affixed. If so, that’s a lot of glass!

    • They sponsored CART from 1980-1997, which used the IndyCar name from 1992-1996 under license from Tony George, the owner of Indianapolis Motor Speedway and the IndyCar trademark.

  6. The building’s Bridge Crane appears to be in the 5 Ton (10,000 lbs.) to 10 Ton (20,000 lb.) Class. It is operated by a: “pendant control box ” right next to where the load is lifted, lowered or transported. It has “Creep” or Fast speeds for all (6) movements . A Spreader “I” beam ” with balancing holes to equalize the “front -to -back” load and two more lateral beams (for each axle) with lifting Cradles that raise all four tires , simultaneously , are utilized . Large turnbuckles and choker cables, hooks & clevises are used to equalize tire cradle distances above the glass. After the Packard lands, the demonstration is “Proofed” before being photographed or seen by the public ., with the Crane & Rigging in “standby mode” (still ready to “catch the car”). Lastly, the Crane & Rigging are moved to the end of the building . “Tempered glass” requires a special cooling process . Edwin W.

  7. Sadly, the automotive glass division was sold off a few years ago. It is now called Pittsburgh Glass Works, and is mostly produced in China.
    They also sold their flat glass division to Mexico-based Vitro.

  8. Those center bumper guards were to prevent the “locking” of bumpers in a minor collision in traffic. The bumpers one one car could ride over those of the other and “lock” the cars together. Such protectors were often called “over-riders” and were common accessories.

  9. The Herulite PPG tempered glass was truly a quality high volume product. So much so, that Ford Motor Co. used it starting in 1941 and ran through 1948 for the unique cuved oval one piece “back light” on all the coupes and sedans, which represented millions of autos over those years. You will rarely if every see one in broken condition except for bullet hole or some massive object having struck the glass. Most restored cars of this series will have their original Herculite rear windows. They did not scratch easily either.

    Herculite was used on all of the huge military 60″ anti-aircraft “searchights” of WWII era. They were individual slice-of-pie panes in metal frames on the large 60″ round glass panel. The lights were on mobile trailers so glass had to be very tough. Good Job PPG!


Leave a Reply

Your email address will not be published. Required fields are marked *