After the devastating events of 2011, many properties had to be demolished throughout the city of Christchurch, including some very high risks areas that were susceptible to cliff collapse. New methods were needed to minimise risk to demolition crews working on these properties.

In a world first, Protranz have created the remote controlled excavator, whose sole purpose is to minimise risk to demolition operatives undertaking works on cliff tops or at the base of cliffs. Many of the properties that Protranz have cleared either have parts of the house on the edge, overhanging the cliff face or alternatively at the bottom of the cliff, with boulders ranging from a few kgs to 300 tonnes (the Sumner RSA) scattered/ crushed into the side of the structure.

The waste / debris is managed like most other demolitions, only that it is brought back to a safe area (under the discretion of the Geotechnical Engineers) and loaded into trucks / bins. The risk of asbestos is assessed up-front, and should the environmental scientist consider there to be significant ACMs in the building, then the call will be made whether or not it should be a completely dirty demolition.

Protranz work closely with Geotechnical Engineers on Port Hills sites, and their knowledge is the key to determining the factor of safety, and whether or not it should be a remote controlled demolition or regular demolition.