Penrose Old Control Building Demolition

Safety is paramount on every Cassidy work site, but even more so when we were given the job of demolishing an asbestos-riddled 1930s-era substation for Ventia on behalf of Transpower.

The Old Control Building (OCB) was located directly adjacent to SH1 within the live Penrose Substation, which supplies electricity to a large portion of Auckland – so the stakes were high if something went wrong.

We began by steadily and methodically removing the asbestos – a complex process in the live substation environment, requiring daily air monitoring and constant consultant inspections. While this continued, we erected 3.6m-high protective hoardings around sensitive transformer assets to protect them during the demolition phase.

Once the site was cleared of asbestos, we infilled three large pits with more than 200m³  of concrete to create a stable platform for demolition, then brought in a 30 tonne excavator fitted with a cracker jaw, which chewed through the building in a matter of days.

In keeping with our sustainability policy, timber sleepers were recovered and donated to a Transpower employee for woodworking projects.

With demolition complete, we shifted focus to more than 1600m² of reinstatement works, including asphalt surfacing, 150m of vehicle barriers, new access lids, bollards, channel grating and surface drainage infrastructure and a concrete vehicle ramp within the 220kV switchyard.

We worked closely with the client on design elements and happily accommodated amendments as they occurred. We even managed to add a new toilet block housing long-needed facilities for the substation team.

All work was carried out under stringent health and safety controls, and an external audit delivered excellent feedback on our safety approach.

“I’ve been working with the fantastic team at Cassidy Construction. I’ve been really impressed throughout, but the highlight so far was observing one of the best prestart conversations I’ve ever seen. The team talked about the work they were doing, how STCKY risks would be managed, and ensured everyone was clear on the most important controls. This is what a good prestart can look like! Let’s see more of this on our construction sites, please!”

Paul Robertson, BlackSwan Safety