Following the 7.1 magnitude earthquake which struck Christchurch on September 4, 2010, and the thousands of subsequent aftershocks, the New Zealand logistics industry began rethinking their storage approach.

When an earthquake occurs, ground acceleration can increase the horizontal loadings on storage systems by a factor of 10 or more. Rack frames and beams respond by swaying to and fro, and the total mass within the racks – the stored pallets – begins to move in relation to the ground, creating inertial cross-aisle (transverse) and down-aisle (longitudinal) forces within the rack structure.

Why ColbyRACK?

While some rack suppliers make use of vertical and horizontal bracing to stabilise the rack in the longitudinal direction, this can be problematic since the bracing is prone to damage when putting away and retrieving pallets, possibly reducing its effectiveness under load.

Colby avoids the use of down-aisle bracing at the rear of rack frames whenever possible, preferring instead to opt for the use of “standard” racking uprights and beams, increasing in size as necessary to accommodate the seismic loads.

Colby also uses chemical anchors and special seismic baseplates, designed to behave in a predictable manner in the presence of uplift forces, along with heavy-duty cross bracing, super-strong 4-tang beam connectors, and a full range of rack damage protection designed to eliminate day-to-day damage which can weaken the structure.

Seismic Racking Case Study: Countdown Christchurch

Countdown’s ColbyRACK storage system, designed to cope with the extreme forces generated during seismic events, coped efficiently with ongoing aftershocks following the 7.1 magnitude earthquake which struck Christchurch on September 4, 2010.

The storage system, designed and manufactured in Australia by Colby, has been engineered to sway in a controlled manner in response to ground movement.


From planning and design, right through maintenance and your annual rack inspections, Colby can provide the services you need to get the most out of your storage investment.