The construction of the Heron Quays phase of the project presented us with enormous challenges. The site is surrounded on three sides by water, with two-thirds of the fourth side also in the existing dock and the remainder comprising the existing estate. This particular project included three 30-storey office towers, two 13-storey office buildings, two winter gardens, a retail mall and a large parking basement. The challenge was to build it all concurrently.

Hundreds of weekly deliveries had to be scheduled and controlled. In 2001 alone, over 225,000 cubic metres of concrete and 40,000 tones of structural steel were delivered to site. This was followed by over 100,000 square metres of cladding, miles of pipe, cable and duct, as well substations, transformers, over thirty chillers and dozens of cooling towers.

Our solution was to build a cofferdam in the dock, put a road on top of it and pump out the water. Earth ramps were constructed to get traffic to the bottom of the hole for the substructures, and once the basements were constructed, delivery trucks reached tower crane pick points and materials hoists via the cofferdam roads. To keep concrete production and delivery under close control, a batching plant was built on a barge anchored in the dock. Aggregates were delivered by barge to keep truck movements on the local roads to a minimum. Our extensive use of river traffic included sea-going barges from the continent for the delivery of large structural steel fabrications. Delivery trucks were all booked in advance and marshalled in a holding park until their allocated off-loading time, when they were called forward.

Having completed the buildings, the cofferdam was removed and the fill hydraulically pumped to excavation points for loading onto barges. Finally, the outer steel sheet pile wall was removed.