Steel rises to an enormous logistical challenge

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The $25million Newmarket Rail Station, Auckland’s second busiest train station after Britomart, is due to open by 2010.
Newmarket Rail Station is a critical part of “Project Dart”, Ontrack’s $600 million upgrade of Auckland’s rail network and the Auckland Regional Transport Authority’s programme for improving rail stations.

At the gateway to Newmarket’s fashionable Broadway, this spacious world-class facility is a resolutely modern public building.
The concourse structure is 5m above the track and the southern concourse roof is between 12.5m (centre) and 14m (outside edges) above the track level.
The length of the building is approximately 37m. The architects, Opus International Consultants, have reflected the futuristic urban appeal of highly efficient city rail transport services.

“Highly efficient” is also a hallmark of the construction of the building. A professional integrated approach to project management, the flexibility of steel construction on a challenging site, and the precise art of steel fabrication really came to the fore.

Steel constructors George Grant Engineering, Hawkins Infrastructure project managers and Opus engineers worked closely together with Ontrack for safety around trains. 
The degree of collaboration on quality, environment, and health and safety management was exacting and impressive.
With all the high spec requirements, and the unusual challenges of a site with live trains running underneath, steel was a logical choice for many reasons.

For strict earthquake and environmental safety standards alone, a steel structure has many significant advantages. The strength and lightness of steel framing, its ductility, and the processes of fabrication mean steel can be engineered to meet precise requirements.
The limited access to the site by day, space restrictions on site, its closeness to live tracks, and with residential apartments within a stone’s throw on either side presented many organisational challenges.

The engineers, architects and construction team developed a unique scheduling plan. Work had to be carefully phased, and pieces of the steel structure brought in in segments.
The versatility of steel, its strength combined with light weight, and its ability to be easily formed and joined solved many logistical problems.

“Our only option was to shut trains down at night and drive up the track,” George Grant Engineering’s Scott Delacy says.
“We brought in roof rafters that were 26 metres long each, and tree heads for the rafter support structure.”

Extremely large members were made in sections in the workshop and erected on site, with high-spec QA requirements calling for “near impossible weld procedures”.
“There was careful planning in the fabrication stage. We had to set up a jig in the workshop to build the ‘tree heads’, the column structures designed to support the roof.
“The only way to do it was to actually build each one upside down in the shop then take them to the site to erect,” Mr Delacey points out.

On site, the columns stood 12 metres high, filled them with concrete, then welded “tree heads” on all, and on top of these, a rafter. In order to fit the roof structure on, everything needed to be exact within 2mm.

The design and the project’s unique challenges made steel the obvious choice for the structure. It is simply easier with steel than concrete to do things such as make pipes look like flower heads, or to integrate with glass.

Curves using steel beams bent to a certain radius or segmented curves or combinations of both can create members that follow the outlines of irregular facades, arches or domes.
“You can form steel,” Mr Delacey says. You can bend it, roll it, cut it and do all kinds of things with it. With concrete you have to pour it into the thing.”

The Newmarket Station is a great example of how great design, brilliant logistics, exacting attention to detail from all contractors, and the strategic choice of steel meant construction challenges were waded through without a hitch.

The result is a very strong and uncompromising building that commuters will love.