After being awarded the contract to construct the NZ Post distribution centre in Wiri, Macrennie Construction was faced with a large project involving many subcontractors and complex, state of the art parcel handling machinery installation needing to be coordinated.  

The Platform Challenge 

Part of this project involved a mechanical plant platform, located above the Office block. this platform measures 22m x 9.5m and supports more than 6,000 kg of HVAC equipment, originally designed in steel, this platform was to weigh in at more than 23,000 kg, that was without adding the architectural louvre screens.  

Platforms of this type provide a lot of challenges for project managers and designers, beginning at the design phase the platform needs to incorporate the visual requirements of the Architect, the conformance requirements of the structural engineer and location, unit selection, layout, and service access needs of the HVAC engineer.  

The Solution 

For this project Monkeytoe projects director Toby worked with the Macrennie to offer a competitive design, manufacture and installation solution with our XBEAM product. This began with the concept design process (link to this article) involving Jarrod and our Engineer Johannes. Working with all the stakeholders and planning the job was our project manager Heinrich and design manager Ben. The final design of the platform came in at 6077kg nearly quarter of the weight of the original design! meaning far less structural load on the building and less need for extra capacity in the portal frames it attaches to. 

Being one port of call for design and delivery certainly made it easier for according to Steve Anderson QS and PM for Macrennie’s and noted it offered good, more economic solution to the original design for this project The final design dimensions and revisions were able to be confirmed without holding up the portal framing delivery or needing provide welded post stubs before the roofing Iron was installed. Without any onsite fabrication needed the aluminium supporting posts for the XBEAM platform connect to the portal and can be installed after the roofing iron.  

By having one design and supply contractor Macrennie eliminated what would normally be 2, 3 trades with structural steel contractor, the Webforge installer and the louvre façade installer each requiring time and quality management.  

The Onsite Action  

Working Brad Somervell the site manager, Heinrich planned the installation to be in one single lightweight lift. Using 4 installers the entire platform was assembled on the ground without lifting equipment, complete with the louvre screen framing and some of the mesh floor and screen.  

Using a long reach crane the entire platform was then lifted to the roof in a single crane lift at 6,000kg. Once on the roof it took 3 installers just 4 days to complete the install the of 65m² louvre screen, 180m² of mesh decking and all of the bracing elements.  

All of the installation was carried out without any welding or steel shavings above the new roof and resulted in a durable, recyclable aluminium platform that will need no coating maintenance and last the life of the building. 

Onsite Alteration 

When final onsite adjustments meant an HVAC penetration went through a load bearing member, the Monkeytoe design team quickly developed an engineered solution which was then implemented onsite. With the modular design and marine grade aluminium of the XBEAM meant the change to the platform was fast and required no steel shavings or welding above the roof and no damage to a galvanised (or painted) surface that would be the case in a traditional design