Analysis - How much can the public find out about the quality of the steel going into the country's high-rise buildings?

Photo: Supplied to RNZ

RNZ set out to do just such checks some months ago, at the two biggest apartment blocks currently going up in Auckland and Wellington - the 52-storey, 187m high Seascape; and the 20-storey, 59m building at 111 Dixon St. Here we report on the very different outcomes.

The NZ Society for Earthquake Engineering has said lawmakers should look at more stringent building codes for apartment buildings in high-risk quake zones. Wellington is high risk; Auckland is low risk.

RNZ found Wellington City Council took a largely hands-off approach to the steel supply, contrasting with Auckland Council's hands-on approach that involves far more rules and oversight. It was more difficult and took much longer to get information about Wellington's Dixon St project than about Auckland's Seascape.

Photo: Supplied to RNZ

The country's only steel research group, the Heavy Engineering Research Association (HERA), wants other councils to be as rigorous as Auckland, which began developing tighter rules for structural steel three or four years ago.

That's in response to what's been called a "perfect storm" of increased risks of steel being non-compliant that are facing engineers, builders and consenting councils - this is what industry body Steel Construction New Zealand (SCNZ) warned the Christchurch City Council in March 2016. The likes of major engineers Beca have warned of the need for rigorous controls on importing structural steel.

SCNZ has drawn up a five-page checklist for importing structural steel because councils were asking for one. It details 38 questions to ask about the steel itself; its fabrication, its welding, the welding inspection and coatings (which protect from rust and fire). SCNZ's sister body HERA has just released a complementary 40-page steel procurement compliance guide.

Two cities, two projects

All the steel for both projects is being imported from China.

The Dixon St contractor is Arrow; the engineer is Stephen Mitchell Engineers of Auckland; the steel fabricator (welder) is a small company near Shanghai, Yangzhou Maorui Steel Structure Engineering, set up three years ago; the steel importer is Pinnacle Rigging of Palmerston North. Pinnacle is responsible for the Inspection and Test Plan (ITP) which the engineer signs off.

The Seascape contractor is China Construction New Zealand; the engineer is Mott MacDonald; the steel importer and fabricator is JingGong Steel of Jiangsu, China - JingGong and China Construction are doing the ITP.

Auckland Council says the Seascape steel is coming from three Chinese mills: Nanjing Iron and Steel, Jiangyin Xingcheng Special Steel Works and Nanyang Hanye Special Steel. None are licenced by the ACRS, however, the council says the steel from all three "can be identified from manufacture in the mills through to fabrication and erection phases … unidentified steel shall not be used".

Seascape's steel quality controls have previously been called into question. JingGong has suggested that New Zealand's "local strict access system adds one more barrier to stop the entry of Chinese enterprises".

Arrow and Pinnacle say their testing regime for Dixon Street is first-rate.

"The testing regime for this project far exceeds what is naively commonplace here in New Zealand, where it is commonplace to accept product because it is made in NZ!!" the steel supplier, Pinnacle Rigging, told RNZ by email.

The steel is coming from six mills. Pinnacle has not named them but has confirmed none are licenced by the Australasian Certification Authority for Reinforcing and Structural Steels (ACRS). Few, if any, Chinese mills are. ACRS is a privately-run steel quality control agency that Auckland Council uses as the benchmark for steel mills.

All the Dixon St project's steel tests are being done in China by an accredited lab TUV Rheinland.

Arrow and Pinnacle say its test reports show all the steel has passed, for its mechanical and chemical soundness, as well as the welding. They say TUV is testing:

A sample from each batch of steel from the six mills

15 percent of welds. This is up to the Standard for regular steel, though seismic steel requires more inspections

Pinnacle provided a few pages of test reports to RNZ.

These test reports are not recognised by this country's lab accreditation authority IANZ. "Even though TUV is accredited, as these certificates have no CNAS logo, IANZ are unable to recognise them," IANZ said. CNAS, the China National Accreditation Service which is a state agency, is IANZ's equivalent in China.

* Auckland Council provides RNZ with many pages of details, as well as ongoing updates when requested over several months, about the quality controls it's imposing on Seascape steel.

** AC works with SCNZ and HERA on a new 40-page steel compliance guide. HERA says this provides "the absolute minimum requirements".

*** AC develops its own step-by-step guide to enforcing certain tests and checks according to who is making and welding the steel, and what it's being used for.

**** AC orders an inspection of the Chinese fabricator by independent NZ welding inspection experts Southern QA. This is a follow-up to check the factory has acted on five previous recommendations to improve quality and traceability. This [https://www.documentcloud.org/documents/5499998-Seascape-SQA-Report-July-2018-Customs.html audit report is released to RNZ.

An example of a detailed response about Seascape steel, from Auckland Council in July. RNZ's questions are on the left: