App 1 - TODS - Bridge Certification

Current Capacity: Our calculations indicate that the current capacity of the bridge superstructure
is suitable to carry 7.5 tonnes allowable GVM (single axle load must not exceed 3.75 tonnes). The
nature of timber is such that it will continue to dilapidate and lose capacity as time passes.

It is essential to impose a 10km/hr speed limit using signs, to reduce the “bounce” effect of the
vehicle load on the bridge.

Please note that the substructure of the bridge was not assessed during this Level 3 investigation,
as the depth of these supports are not visible. An extensive investigation would be required to
assess the substructure.

Short-Term Recommendations: We strongly recommend the following:
   • Installing and maintaining in-ground termite baits near each abutment.
   • We consider it essential to install 10km/hr signs at both ends of the bridge.
   • We consider it essential to install 7.5-tonne load limit signs at both ends of the bridge.
   • We recommend that a Level 1 (visual inspection) be carried out every six months until the
       next Level 3 inspection on/before 30 January 2022.

The Level 1 inspection shall be carried out by an experienced bridge technician/builder.

The Level 3 inspection shall be carried out by an experienced bridge engineer.

We are happy to provide detailed designs of repair/replacement works to allow for the bridge to
support a heavier vehicle load, under an extension to the original Agreement. At this preliminary
stage, the repair works is likely to include the installation of larger diameter replacement
girders/logs and load distribution boards under the decking.

Please note that due to the sizes and severity of defects of the existing girders, we suspect that it
would be more cost efficient to replace the existing superstructure rather than undertaking
maintenance on the bridge.


Yours faithfully,




Chris Dowding – R.P.E.Q. 8339
07 5449 9600 | [email protected]
TOD consulting engineers