A continuing trend of excellence



D&H Steel Construction’s ability to deliver exceptional workmanship has again received the highest praise  at arguably the most prestigious event in the steel construction industry.

The company was just awarded the 2019 SCNZ Supreme Award for Excellence in Steel Construction for its stunningly successful work on the AIAL International Departures Terminal redevelopment.

As impressive as this sounds, D&H Steel were actually finalists for two other projects at the 2019 Excellence in  Steel Awards.

The ETNZ refurbishment at the Viaduct Events Centre, Auckland was a finalist in the Under $500K category, and D&H Steel’s work on the University of Auckland B507 Park West, Auckland was a finalist in the Over $3m category.

D&H Steel CWB manager John Frederickson says the company feels truly privileged  and honoured to receive such a  prestigious award.

“It’s quite an honour to have been awarded the best project for the year by our industry body,” he says.

“We’re bit like the All Blacks in that when they score a try, they don’t show their excitement, but they smile on the inside. We’re really proud of our achievement and we smile about it on the inside.”

D&H Steel contracts manager for the AIAL project, Richard Hine says the award, understandably, means a lot.

“It was a large project even by international standards, involving most of the D&H  Steel staff at some point throughout its  long duration.”

Richard says “he has heard the project described as like doing open heart surgery and that he felt this description was accurate, as basically we had to open up the existing terminal, undertake work in the ‘heart’ of the building while it remained alive. The judges acknowledged the  depth of expertise required to achieve the final result.

“Winning the award demonstrates the skills of our team and our ability to develop strong relationships with long term clients and work dynamically with other consultants to troubleshoot and
find solutions. As always we found BECA awesome to work with.”


About the AIAL International Departures Terminal redevelopment

In 2015, D&H Steel Construction was appointed as the steel contractor by Fletcher Construction to deliver Auckland Airport its International Terminal Retail Expansion project.

The expansion is in line with the airport’s 30-year vision to make the airport future-ready by eventually increasing its capacity to 40 million passengers a year by 2040 from its current 14 million.

The $200m multi-faceted project involved nearly doubling the size of the international terminal departure processing zone, reconfiguring the landside farewell area, building a new and expanded security screening and processing area, along with building a new passenger lounge and duty-free shopping hub.It also included the removal of significant legacy structures, such as redundant mezzanine plant areas plus a bridge and stairs. The reconfiguration improved the flexibility of the terminal for future alterations and enabled higher ceilings  and unified public spaces.

The project was extremely complex, starting as phases 2 and 3 and fairly rapidly grew to capture phase 4. It encompassed a vast number of interfaces with the existing structure requiring numerous minor modifications and resulted in over 30 discrete packages of work.

All this activity was required to take  place against a tight construction  programme while the airport remained operational and minimising the impact on passenger movements or disruption to flight schedules.

D&H Steel has been involved with the airport’s development for almost 40 years and understands what is required when working in this challenging, unrelenting, operationally live environment. At the peak of the contract, D&H had over 40 staff on  site booking some 90,000 man hours, on  top of the 4000 man hours of work undertaken offsite over the 24-month duration of the project.

Auckland Airport’s acting general manager of Delivery and Development, Steven Crook, said the project is probably the toughest job the airport will ever do. “I want to thank everybody for the massive effort in out  there. Thank you for getting the job done. The delivery of the work was fantastic, and we’ve had rave reviews from all our customers so far.”

The project’s  three major components

1. New truck dock with immigrationprocessor above

The design of this area needed to support the functional brief of an immigration processing area with a low-vibration environment for the scanner operation above a space for truck turning movements.
Resotec, a constrained damping layer, was installed under the ComFlor decking resulting in improved dynamic performance by increasing damping hence limiting floor vibration and achieving a low-vibration environment.

The baggage conveyor, running through the centre of the site, needed to remain fully operational at all times. A large portion of the steelwork had to be installed in a carefully planned sequence, with floors backfilled later without crane access, etc.

2. Departures/Retail area

In the large retail area, the overriding objective of the structural design was maximising open space.

A complicated long-span trussed roof system (50 metre maximum span) was constructed from 15 trusses preassembled from 29 segments that are supported by the surrounding three existing structures.

Spans were deliberately configured to apportion load to existing foundations that had the redundant capacity. As a consequence, very costly and disruptive foundation strengthening was avoided.

This was an immense design, construction methodology and health and safety challenge as passenger pedestrian flows continued underneath the work area.

The new roof was constructed first above the existing roof which enabled a myriad of low height roofs and leaking internal gutters to be removed. Ultimately, this solution delivered a spectacular large unified departures area.

3. New large Level 3 plant room, lifts and balconies

The design had to consider the surcharge load on the existing foundations.

The original Ministry of Works designed terminal proved to be exceptionally flexible and analysis found it could cope with an additional level. In terms of the piles, these are extremely difficult to strengthen in an operating building, and the geotechnical engineers managed to demonstrate sufficient redundant capacity.

This was a tricky exercise due to there being no piling records. However, through collecting enough anecdotal evidence, such as interviewing the “senior citizens” who installed the piles, it was possible to demonstrate no strengthening was required if the weight of the new structure was minimised. This was achieved with the extensive use of optimised lightweight custom welded beams and columns.

Innovation in fabrication and construction techniques

Having in-house welded beam manufacturing enabled D&H Steel to fabricate custom welded beams to suit specific geometrical and  strength requirements.

The fabrication of the large trusses was critical to the overall program there was no time to leave anything to chance.

D&H Steel troubleshot the entire workshop process to identify potential bottlenecks  and developed unique material handling systems to manoeuvre the 4.5m deep trusses up to 26m long around the workshop and for trial fit-up.

Locations within the workshop were designated truss laydown areas. Every aspect of the fabrication process was meticulously planned, from resource scheduling to logistics management. The fabrication of 15 trusses went incredibly smoothly and delivered to site on-time over an eight-week period.

An equal level of planning went into the installation process and the methodology that was developed and adopted, which was also a major factor in the success of  the project.


D&H Steel Construction
42 Mihini Road
(09) 839 7250


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