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Thrie Beam Guardrail

Guardrail designed for high-centre-of-gravity vehicle containment.


  • Guardrail manufactured to state road authority specifications
  • The additional corrugation in the rail element stiffens the guardrail system
  • The higher mounting position of the rail increases its ability to contain larger vehicles with a high centre of gravity
  • Can be used in verge or median locations
  • Hot dip galvanised in accordance with AS/NZS 4680
  • Thriebeam Guardrail FAQs

What is the difference between Thriebeam guardrail and W-Beam guardrail?

Thriebeam guardrail is a stronger version of the w-beam guardrail systems. The additional corrugation in the rail stiffens the system, making it less prone to damage during low speed and moderate speed impacts. It also allows higher mounting of the rail, which increases its ability to contain larger vehicles under some impact conditions.

How does Thriebeam guardrail function?

Safe vehicle containment and re-direction is developed through a combination of the flexural resistance of the thriebeam guardrail and the bending resistance of the supporting posts.

Upon impact, the posts absorb some of the crash energy through post rotation in the surrounding soil prior to separation from the thriebeam as they fully yield. The blocking pieces, positioned between the thriebeam guardrail and posts, minimise vehicle snagging and reduce the potential for the vehicle to vault over the barrier by maintaining rail height during the initial stages of impact.

Once the thriebeam guardrail separates from the posts, the rail forms a re-directive ribbon, guiding the vehicle away from the nearby hazard.

What configurations are available?

Thriebeam guardrail may be installed using standard or modified blocking pieces.