Pro BannerSaver brackets have been independently tested in a wind tunnel to prove their capabilities of reducing wind loading. We detail the equipment used, testing method and results below:
Testing carried on a single lamppost column with:
- 2 Banners – 76cms x 203cms (3.08sq.m.)
- 2 sets of Pro BannerSaver Brackets
Methods & Apparatus used:
Distance traveled was recorded on two string pot sensors mounted on the test rig and were calibrated by wrapping the wire around two known diameters and calculating the circumference. Wind speed was provided by our test facility.
- All tests were conducted by our test facility with specialist equipment for measuring wind loading vs deflection. The test was carried out with double banners on a
single lighting column.
- Static conditions were recorded at commencement of test.
- Wind tunnel started and base wind speed, force on banner pole, and deflection were recorded. Wind speeds were held for two minutes while increasing wind
speed at 10mph increments.
- Procedure repeated on fixed arm banner system for comparative measures and the results shown on graph on following page.
Pro Banner Saver’s max loading of 63.42kgs @ 50mph (Based on 2 banners installed on one column total 3.08sq.m).
Linearity of the load cell is 0.57kgs max up to 63.42kgs. Load reduction starts occurring between 20 and 30mph. Wind force overcame the spring force of the system at the above speed, the BannerSaver bracket changed direction of the banner according to the direction of wind. The banner rotated to such a degree that at 70mph some of which started in a perpendicular position to the wind direction, billowed and turned, such that at over 70mph the middle of the banners were actually partially hidden behind the pole. This rotation was very significant in reducing the exposed area to the wind velocity and limiting the force to the pole.
Calculated Reduction in Area
Calculated using A = F / 1/2pCdu2, where reduction in area % was calculated at 90mph or 144.84kmph.
Load reduction starts at – 20 – 25mph.
Reduction in Loading Area: 87.98%
This means that from a total banner area of 3.08sq.m the BannerSaver effectively reduced the wind load area to 0.4sq.m. When this is applied to a single banner installation of 1.54sq.m (760mm x 2030mm) conformity to EN40 is achieved by reducing the wind load area to 0.2sq.m (EN40 stipulates that a standard lighting column must be capable of taking the maximum wind loading exerted by a standard rigid road sign of 0.3sq.m).