Forcible Entry Demonstrations
Air-blast Resistant Window Systems
7.3.1. Annealed Glass
Times recorded for the four-sided attached film on annealed glass were comparable to
those for the daylight film on annealed glass.
Figure 6: Test 6
7.3.2. Tempered Glass
The film created a delay compared to typical break and clear times expected with
untreated tempered glass, especially on the second floor where the time to first break was
26 seconds and the time to clear was 64 seconds.
The times to first break and vent were greater for the second-story tempered glass than
for the second-story annealed glass (tempered 26 seconds to break and vent and
annealed four seconds to break and ten seconds to vent), though the final clear times
were comparable (64 seconds for tempered and 71 seconds for annealed).
Figure 7: Tempered Glass
4-Sided Attached Film with
Laminated, Single-Paned Glass
The laminated, single-paned window panes became a flexible mass when broken,
especially the tempered glass panes. This allowed the firefighter to use the weight of the
tool to push the entire unit out of the framing system rather than requiring them to chop
around the entire window perimeter, as was done for the attached window film systems.
This tended to decrease the time for venting and clearing of the windows.
Hinman Consulting Engineers, Inc