As part of the development of the Northern Water Treatment Plant (NWTP) in the Western Downs of Queensland, Laing O’Rourke constructed a series of three water treatment plants with customised pipes supplied by Redispan.
The process of customising the NWTP Pipe Racks and Brine Towers to affect a Redispan DFMA (Designed for Manufacture and Assembly) Delivery Model demanded a holistic consideration of all aspects of the project.
Design and modularisation
Design decisions and details were taken in the initial stages of the project to facilitate the advancement of design and scheduling of manufacture and procurement on a cost effective timeline.
Initially, Redispan undertook comparison studies between modular vs stick built construction. Through the studies, all elements were taken into consideration, including: remote location, potential extreme weather events, labour constraints and logistics. A project strategy of a modular DFMA Model was determined to cost and schedule.
The modularisation of a similar plant which was previously 'stick built,' resulted in some 300 'module transportable packages' being identified and scheduled to a just-in-time delivery at site. In order to minimise police and escort involvement, maximum transport envelopes were determined. By doing this, the maximum effective facility module size could be achieved.
All modules were detailed by Redispan to achieve the holistic lowest cost to project solution, which encompassed materials, off site and on site labour, and associated camp facilities.
Steelwork was customised to allow for transport and lifting stresses, as well as the configurations and material take offs, which were produced to deliver a 'kit of parts' with every item associated with that module, down to the nuts and bolts.
Studies surrounding Crane Lift and Centre of Gravity were undertaken, with the resultant Purpose Designed Lifting Gear manufactured and supplied. The modules were fully assembled in Redispan's Newcastle facility and transported to site on a just-in-time schedule. The platform and walkways featured in the module design allowed for safe access throughout installation and commissioning, along with providing safe future maintenance access.
This methodology provided improved access for construction personnel and materials, ensuring the assembly area was less susceptible to poor weather.
Project statistics suggest a 70 per cent reduction in site labour and a 60 per cent in project delivery time for the DFMA elements.