Patent 326 is a stunning new Globe Holdings development located right beside the historic site of Patent Slip in Wellington’s Evans Bay. During the early 1900s, a giant cog was used to haul ships ashore for maintenance and repairs. Today Cog Park is being redeveloped and the surrounding facilities dramatically upgraded.

Designed by Warren and Mahoney, Patent 326 includes single and dual level apartments, townhouses and penthouses – all with private balconies and literally a few steps away from the sea on the other side of Evans Bay Parade. In keeping with the nautical theme, the three buildings that comprise Patent 326 have been named Navigator (two storey timber frame), Helmsman (three storey, steel, timber and blockwork), and Semaphore (five storey with penthouses, steel frame). It’s on Semaphore that we focus.

The consulting engineers for the project were Silvester/Clark; Scott Miller speaks about the foundations and structure: “The geotechnical report identified underlying greywacke rock. This was suitable for pad foundations and no piles were required. The structure is mostly steel-framed, with spaced Dycore with timber infills, pre-stressed beams, Interspan and Hibond floors, depending on the span required.

“The seismic loads made bracing critical, with mostly concentrically braced frames on the longitudinal and eccentrically braced frames on the transverse. The shallow steel frames enabled the overall height of the floors to be reduced without affecting the quality of the spaces. In several places the longitudinal frames were ‘squeezed’ for head room; we designed the steel braced frames to function around these areas. In the transverse direction, the dead load was not enough to resist overturning and ground anchors consisting of grouted Reid bar were placed in the greywacke rock. We also worked with the architect to design a structural steelwork stair case that will be the feature in the atrium space entrance to the building.”

Project Manager Ian Leslie of Primus Limited says steel was chosen for the frame for three reasons: “It was more economical than concrete in terms of cost and time. We were able to erect steel columns, prefabricated in the MJH Engineering Ltd workshop, to their full height of five storeys, and proceeded quickly to the roof work. The third reason for choosing steel was the irregular layout of the different levels. The car park occupying ground and level one has a 3.5m high ceiling. Levels 2 and 3 have dual level apartments, and above the apartments on level 4 are eight penthouses. All of the structural complexities arising from variations in ceiling height and floor plans were fabricated entirely offsite by MJH Engineering Ltd, who also did the erection.”

MJH’s Project Manager, Mark Shirtliff, says his company was ambitious to be on site within ten weeks of being awarded the contract. “And we were. But what enabled us to maintain a fast pace was the co-ordination between the architect, Earl Rutherford of Warren and Mahoney, the engineer, Scott Miller of Silvester/Clark, the site manager, Anders Waiker of Aspec Construction, Ian Leslie of Primus, the client’s project manager, and the MJH team. We met regularly to discuss and improve buildability and ensure that Semaphore was pushed along aggressively.” To which Apec’s construction manager adds: “When you have real professionals playing in the orchestra, it makes my job as conductor easy!”

Beneath Semaphore, the car parks will be linked to Helmsman and Navigator by a covered walkway and accessed from above by a high-speed lift. Tenants have the option of using a car stacker system that makes for efficient use of the available height within the car park.

Warren and Mahoney’s Earl Rutherford: “The focus on variation and form ensures that Patent 326 harmonises effortlessly with its surroundings. It’s a considered response to the unique environment of Evans Bay and Wellington’s climate.”