Test Methods and Materials 2011 Glass Railing System Post-Break Performance Testing

In January 2011, DuPont Glass Lamination Solutions conducted a comprehensive technical testing program to characterize the impact strength and post-break performance of glass balustrades (railings) made with commonly specified types of safety glass.


The swing bag testing protocol involves controlled acceleration (by gravity) of a 45.4 kg (100 lb) shot bag, resulting in repeatable delivery of a chosen impact force on glass panels intended for applications such as railings, requiring barrier performance.
What does “safety glass” mean in a balustrade or railing system?
Tempered glass is often used in railings, but retains no barrier properties after breakage. DuPont tested tempered glass, applied-films, and laminated glass panels to compare and record post-break erformance.

“Swing Bag” Impact Tests Were Conducted on A Wide Range of Safety Glass Types Used in Glass Railings

Beginning in January 2011, DuPont Glass Lamination Solutions conducted a comprehensive technical testing program to characterize the breakage characteristics and post-break behavior of glass balustrades (railings) made with commonly specified types of safety glass.

An industry recognized “swing bag” test was conducted under controlled lab conditions, based on the protocol outlined in ANSI Standard Z97.1-2004. This protocol considers the impact loading created by a 45.4 kg (100 lb) shot bag, dropped from various heights. Because the intent of the test was to EXCEED the force needed to break the glass, a shot bag height of 5 ft was chosen for most of the tests, resulting in an impact in excess of 69 kg/m (500 ft/lbs).

Dozens of 107 cm x 122 cm (42 in. x 48 in.) panels were tested for deflection strength and breakage behavior in line-supported and 3-side-supported configurations. The cantilevered panels were mounted and dry-glazed in the channel of an R.B. Wagner PanelGrip™ railing system. For the swing bag portion of the test, care was taken to impact each glass panel at exactly the same location, in the middle of the panel at a consistent height above the floor.

A Variety of “Safety Glass” Types are Used in Balustrades
Safety glass panels tested in the railing system were typical for U.S. railing applications, and included:

Non-Laminated Glass Panels:

  • 12.7mm (½ in.) Fully Tempered (FT) monolithic glass
  • 12.7mm (½ in.) FT monolithic glass with 0.2mm (0.008 in.) applied PET film


Laminated Glass Panels:

  • 6.35 mm. FT | 1.52 mm PVB | 6.35 mm FT
    (¼-in. FT | 0.060 in. PVB | ¼ in. FT)
  • 6.35 mm. FT | 0.89 mm SentryGlas® | 6.35 mm FT
    (¼ in. FT | 0.035 in. SentryGlas® | ¼ in. FT)
  • 4.76 mm. FT | 1.52 mm SentryGlas® | 4.76 mm FT
    (3/16 in. FT | 0.060 in. SentryGlas® | 3/16 in. FT)


Conventional and high-speed video cameras recorded the swing bag impacts, as well as the resulting post-break behavior of the panels, from multiple viewing angles.


Learn more about the 2011 Glass Railing System Post-Break Performance Testing by downloading the case study: