Thrie Beam Crash Barrier installation is similar to W Beam but with heavier handling and tighter tolerances at transitions. The sequence is setting out, post installation, rail mounting, transition treatment, and inspection.
1. Setting out: chainage-by-chainage marking with offset from carriageway edge as per drawing. Confirm transition points to W Beam, concrete parapets, end terminals.
2. Post installation: heavier section posts than W Beam, deeper embedment depending on soil. Hydraulic driver preferred; concrete encasement at rocky strata. Top-of-post level matched to rail centerline geometry.
3. Rail mounting: Thrie Beam rails are heavier and require either a small crane or four-man lift. Lap direction follows traffic flow. Splice bolts torqued in two passes to specified value.
4. Transitions: critical at junctions with W Beam (use approved Thrie-to-W transition pieces) and at concrete bridge parapets (use approved transition sections). Wrong transitions are the most common inspection failure point.
5. Inspection: post plumb, rail line and level, splice direction, bolt torque, zinc coating, transitions, end terminals, reflectors.
Auroguard supplies full installation drawings, transition pieces and field-coordination support with every Thrie Beam Crash Barrier order.