Baulderstone Hornibrook Nepean Dam Project

Dam Isolation Inflatable Packer

48” dam scour pipe valves on the downstream face of a 1920’s constructed dam needed to be removed, repositioned and re-installed at a later date. With 75m water pressure acting against the valve and the only access being approximately 100m below the dam service road, the job required a custom designed and manufactured tool.

AGE designed and manufactured a dual seal inflatable packer system complete with roller housings and

counter weights to balance the system horizontally when submerged in water. The packer system was weighted, balanced and installed via a crane located on the dam wall whilst being directed by divers below. The final packer design was 1140mm OD and had an effective rubber length of 1200mm.

Once the dual packer system was inflated, the monitoring ports provided the confidence for personnel to enter the confined valve access area downstream of the packer supporting the 75m head of pressure.

Inflatable Packer Installation The packer system alone finished the job of holding back the entire dam contents under the head pressure for six months whilst the downstream pipe work was modified.