Del Park Road bridge 4501 — timber bridge modelled from point cloud

A historic timber bridge in Western Australia, rebuilt piece by piece over its life until the record drawings no longer described it.

Location
Australia
Our services
Scan to BIM · As-built model · Comparison against record drawings
Point cloud of the timber bridge at Del Park Road, Dandalup River, Western Australia
Point cloud survey
As-built BIM model of a historic timber road bridge, Del Park Road bridge 4501
The model built out from the survey
Timber trestles and bracing beneath the bridge deck, Del Park Road bridge 4501
Timber substructure of the bridge over the Dandalup River, Western Australia

We modelled it from point cloud, compared the model against the existing plans, and delivered a record that matches the structure as it stands.

No single as-designed state

Members have been replaced piecemeal across decades. Parts have been added, changed and taken away, and each alteration was made to the bridge as it stood at the time, not to the original design. No one drawing describes the whole of it. So the model was built outward from the survey, and the drawings were used only as a check against it.

Timber geometry

Sawn hardwood is not prismatic and does not stay where it was put. Members twist and sag, joints were cut and fitted on site, and no two bays repeat. Every member was modelled in its measured position and orientation against the point cloud and checked back to it, rather than modelled once and copied along the bridge.

Compared against the record drawings

The existing plans were set against the model and every difference recorded — members that are not where the drawings put them, sizes that have changed, elements added and elements gone. That comparison is a deliverable in its own right: it tells the asset owner which parts of the archive can still be relied on and which cannot.

An accurate record

A dimensional model of the bridge as it stands, with survey behind every element. It can carry inspection and condition information, support planning of repair or strengthening, and serve as the record set the archive no longer provides.