The Double Top is a multi-use lightweight barrier top designed for use on the Wonderwall barrier.
All temporary traffic barriers must be able to withstand three classes of wind speeds with the use of ballast. The standard BSB442:2006 states the three classes as follows - Class A: 26.3m/s (58mph) - Class B: 17.7m/s (39mph) - Class C: 8.7m/s (19mph)
The BBS Wonderwall Barrier system was tested under strict conditions at the Full Scale Wind Tunnel at MIRA to determine which wind speeds the barrier can withstand.
Below are the results and guides as to the recommended ballast weight for each wind class:
Class C: Passed to 32.2mph - recommended ballast - 0kg
Class B: Passed to 47.8mph - recommended ballast - 15kg
Class A: Passed to 65.6mph - recommended ballast - 65kg
Boxed configuration: withstood to 65.6mph - recommended ballast 40kg
Height: 1m (2m with Wonderwall Barrier)
Base Width: 0.6m
*All weights are approximate