Giant sculpture a triumph of engineering for Whangarei

The outline of the bow of a ship could just be made out through the mist hanging above the Whangarei Harbour. As the mist lifted, the ship was revealed to be Whangarei’s newest steel sculpture – the Camera Obscura.

The giant sculpture was being transported to its permanent site on Pohe Island overlooking Te Matau a Pohe bridge – the Lower Hatea Crossing – on the edge of the Hatea River. This short journey on the river was the culmination of years of work by a passionate team, supported by a strong community of local businesses and supporters.

The idea for the Camera Obscura was born in 2011 when Whangarei District Council (WDC) called for submissions for sculptures to become part of the Sculpture Trail near the Whangarei Town Basin, ahead of the Rugby World Cup. Local photographer Diane Stoppard and architect Felicity Christian conceived the idea of a Camera Obscura to form part of the trail.

The original design for the Camera Obscura was a wooden spiral, in the same shape as the final design, but much, much smaller. The model and costs were submitted to WDC, but it wasn’t selected for the Sculpture Trail.

Time went on and in 2015, after the iconic Te Matau a Pohe bridge was built, Di and Felicity set their sights on a new location – looking directly at Te Matau a Pohe.

MAKING IT HAPPEN

Felicity and Di realised that to finesse the original design they would need some extra help, and approached friend and local sculptor Trish Clarke. With Trish onboard, the team took a new design back to WDC and this time got the go-ahead to investigate further on the new site overlooking Te Matau a Pohe.

With a site now agreed, the team approached Shane Culham from Culham Engineering. Selling him the vision was easy and with Culhams on the team, the project was destined to go ahead. Whangarei has a long maritime history, and the Camera Obscura has been fabricated from curved weathering steel, designed to represent a ship’s hull.

Culham Engineering operations manager, Dave Cunningham, says the project was an opportunity for Culhams to do something very different to their usual work and support a local community initiative at the same time. “The Camera Obscura has been designed by an architect, sculptor and photographer, so it’s a giant piece of art that happens to be made out of steel.”

A SHOWCASE OF SKILLS

For Culhams, this was also an opportunity to showcase their range of skills and capabilities, taking the design from cardboard cutout to a working camera obscura. Engineer Don Kessell took the basic cardboard model and engineered it from start to finish, working through the intricate details of each element of sculpture.

With no straight lines, the sculpture was 3D modelled and then broken down into parts which could be engineered – essentially taking the model, making a pattern and then fabricating all the parts. Don says it was about determining what was possible and working through all the issues of creating a sculptural artwork.

The Culhams team also ensured that the end result would not only look amazing, but it was also a functioning building, meeting all the necessary technical requirements and specifications.

“Unlike most of our industrial work, this design had very few straight lines and involved many highly skilled workers; it gave our apprentices a new learning opportunity,” says Dave Cunningham. “Over the course of the build there would have been several apprentices working on different parts of the project, learning first-hand how a complex build like this comes to life.”

The steel core is made from a series of rings which line up to create the large outer shell of the building. This curved steel was rolled onsite at Culhams and welded together to form the shape of a ship’s hull. Once the outer shell was completed, work started on the inner walls and the camera mechanism itself.

To make sure the foundations were accurate enough to fit the steel, Culhams made a steel pattern which Harnett Builders used to pour the concrete, creating the perfect pattern for the foundation platform. Once onsite, the steel and foundations fitted together perfectly.

HEAVY HAULAGE SKILLS

Moving a 16 tonne steel sculpture that measures 8 x 12 x 8 m is not for the faint-hearted. The sheer volume of the sculpture meant that road transport from one side of Whangarei to the other was really not an option without some major road closures. As the Culham site is located next to the water, the team realised they could easily use the river and transport the sculpture by barge.

After some trials and testing in the yard to optimise the rigging of the odd-shaped load, it was transferred by crane onto one of Culhams’ heavy haulage trucks. The truck took the sculpture a short
500 m to the barge which then transported the sculpture up the river. Once back on dry land, the sculpture was again carefully moved onto a truck and transported onto the site.

WHY A CAMERA OBSCURA?

A camera obscura (Latin for ‘dark room’) is an optical device that led to photography and the photographic camera. The camera obscura device consists of a box or room with a hole in one side. Reflected light from an external scene passes through the hole and strikes a surface inside, where it is reproduced, inverted (thus upside-down), but with colour and perspective preserved.

Historically, camera obscura structures were located on beach and river fronts in the UK and Europe. There are many buildings around the world which house a camera obscura and these generally have a turret, with mirror and lens, which project onto a table in the room. The Camera Obscura in Whangarei will be the largest sculptural obscura in the world, with the image projected onto the entire wall.

Positioning the camera and creating the building to house it involved some specific challenges on how to actually get the view onto the back of the room. The 3D model created by Culhams allowed them and the project team to see how the camera obscura would actually work, and to work out where to place the ‘camera’ to ensure the image of Te Matau a Pohe was projected onto exactly the right spot on the wall.

The building shape, along with a carefully crafted camera mechanism, enhances the visitor experience as visitors can adjust the aperture themselves. A large 3 m chain is attached to a lever which slowly moves the mechanism, changing the depth of focus. This internal camera mechanism is housed in perspex and glass, allowing visitors to see the wheel, but protecting it from dust and damage, and creating a beautiful optical experience for visitors.

FINISHING TOUCHES AND COMMUNITY SUPPORT

The intricate design work on the front of the Camera Obscura was designed by Trish Clarke and also Poutama Hetaraka from the Hihiaua Cultural Centre. This created another opportunity for the Culhams team to showcase their skills. The 6 mm steel was first carefully rolled, ensuring it didn’t break, and then it was plasma laser cut before being cleaned to highlight the sharp features, and then galvanized by another local supporter, Avon Industries in Kamo.

The details of the design tell the story of the river from both Maori and European perspectives, creating another feature on this stunning artwork.

Diane Stoppard says that all the local contractors have been phenomenal. “The project wouldn’t have progressed this far without the support of local businesses like Culham Engineering, Whangarei District Council and the Provincial Growth Fund investment,” she notes. “Culham Engineering had the scale and capability we needed to be able to manage everything – from design, fabrication and painting to transportation of the steel.

“The skill and professionalism of the team, particularly Ralph Egert, Don Kessell and Dave Cunningham, meant that this has been a seamless construction of a complex build. It’s definitely been a team effort, with an extensive range of local businesses working alongside Culhams, including Harnett Builders, McKay Electrical and Bowling Contractors,” Di adds.

“Something like this which can garner so much local support doesn’t come along very often. It’s been a wonderful project to be involved with and everyone is looking forward to the Camera Obscura opening in November 2020.”

Visit the Camera Obscura from late November, or for more information, visit the Culham Engineering website

 culham.co.nz/project/camera-obscura/