RAMSHIELD w-beam guardrail safety barrier achieves a controlled redirection of errant vehicles by releasing the w-beam guardrail from the post at an optimal load to retain rail height, limit dynamic deflection and to allow the post to collapse without tripping the vehicle.
The separation of the w-beam guardrail from the post is achieved by a release tab incorporated into the post. The tab is designed to pull forward and tear from the post and remains connected to the rail to ensure there is no debris from the system that may otherwise present as a danger to other motorists.
RAMSHIELD uses standard state road specified w-beam guardrail and standard fasteners meaning there is very little risk of inadvertent use of non-compliant items.
RAMSHIELD w-beam guardrail safety barrier has been fully crash tested and evaluated according to the specifications for Test Level 3 (TL3) of the AASHTO Manual for Assessing Safety Hardware (MASH). The MASH specification is an update to and supersedes NCHRP Report 350 for the purposes of evaluating new safety hardware devices.
MASH is also the basis of testing procedures for road safety systems as stated in AS/NZS 3845.1: 2015 Road Safety Barrier System and Devices. Australian state road agency w-beam guardrail designs do not meet the MASH performance level.
RAMSHIELD w-beam guardrail safety barrier has been crash tested as follows;
- 2270kg pick-up truck travelling at 100km/h and 25 degrees. Recorded impact energy of 156kJ.
- 1700kg passenger car travelling at 110km/h and 25 degrees. Recorded impact energy of 142kJ.
- 1100kg passenger car travelling at 100km/h and 25 degrees. Recorded impact energy of 83kJ.
Two (2) impacts were performed with the 1100kg passenger car, which included a reverse direction impact.
The 1700kg passenger car impact at 110km/h and 25 degrees was performed with the RAMSHIELD posts installed just 200mm from the rounding point of a 2H:1V embankment slope. The vehicle was safely contained and redirected.
The most common Australian state road agency design comprises w-beam guardrail supported by c-posts and steel blocking pieces. This design has a reduced capacity limit when compared with RAMSHIELD. The only successful published crash test performed with c-posts and steel blocking pieces was undertaken with an 1850kg passenger car travelling at 100km/h and 20 degrees. The nominal impact energy was 83kJ and the published deflection was 0.7m. This impact is comparable to the 83kJ RAMSHIELD impact performed with the 1100kg passenger which recorded a deflection of 0.78m, a similar deflection result to the state road agency design comprising w-beam guardrail supported by c-posts and steel blocking pieces.
RAMSHIELD has a system width of just 180mm, the narrowest width of Australian approved w-beam guardrail safety barriers.
The finished w-beam guardrail height of RAMSHIELD is 730mm. This height is compatible with end terminal and transition designs.
The RAMSHIELD post is just 1560mm long and is embedded 880mm into the ground.
Yes. The RAMSHIELD post is driven directly into soil. There is no concrete required.
Yes. RAMSHIELD posts yield by bending near ground level. Restraining these posts below ground does not alter the yielding action of the RAMSHIELD post. This is a significant performance difference from the state road agency c-post designs which yield through post rotation in the surrounding soil. These c-post designs posts must be placed in augured holes filed with compressible fill material when stiff ground condition are encountered.
Positioning the top of the RAMSHIELD post below the top of the w-beam guardrail eliminates a snag point for motorcyclists.
No. RAMSHIELD is installed using standard w-beam guardrail panels and standard guardrail fasteners as per Australian state road agency designs.
Posts and w-beam guardrails are manufactured by Safe Direction in Australia using BlueScope Steel. Items are hot dip galvanised after roll-forming.