Support Solutions and Fabrication Ltd were approached to help solve the dilemma. The BP Norge AS Valhall Accommodation module was 100 tonnes over its required weight limit.
The challenge was to devise a support system that did not take up any more physical space, carried the same loads and weighed less than standard steel/stainless steel systems and that was also cost effective.
The material had also to face the considerable demands of a harsh marine environment and as such aluminium extrusion ticked all the relevant boxes. Additionally the system had to be totally compatible and interchangeable with conventional stainless steel products as well as being viable and marketable in its own right.
As a result Alphastrut was conceived, with aluminium extrusions as the material and product of choice.
Support Solutions worked in conjunction with Hydro Aluminium Extrusion UK to design a profile that would meet their demanding requirements.
Hugh Hastie, National Sales Manager for Hydro said, “Extruded profiles allow for far greater flexibility in design and ease of construction, whilst still retaining the load carrying capabilities of conventional systems”
The right properties
“Aluminium is one third the density of steel and when alloyed can produce materials with much higher strength to weight ratios. This characteristic is exactly what was needed to retain strength whilst reducing weight.”
“Aluminium also has a natural oxide film which provides resistance to corrosion and as one of the very few Qualanod approved anodisers, Hydro could also enhance the corrosion resistance by providing an anodised product. This gave the profiles a life expectancy of at least 30 years in a marine environment – as good as marine grade stainless steel.”
This capability to finish on site, in conjunction with in-house fabrication and assembly facilities allowed Support Solutions to entrust the supply of both long length and fabricated brackets to Hydro.
Environmentally, aluminium is non-toxic, safe to handle and is endlessly recyclable. And like most metals aluminium does not burn and can be used in fire-resistant structures where appropriate. The high thermal conductivity of aluminium means it can quickly transfer heat away from a localised fire.
All these characteristics mean that it is an ideal material for use in construction, being light and strong. Lightweight also means less loads on supporting structures, easier handling and reduced transport costs.
Alphastrut the answer
Alphastrut is 50% of the weight of standard systems which are made of steel and stainless steel. However it has comparable load carrying properties and life expectancy. The cost of Alphastrut is approximately 60% of conventional stainless steel systems.
Alphastrut has been embraced by the BP Valhall/SLP design teams who have been supplied with several thousand lengths of various profiles and in excess of 30,000 brackets which were also extruded, anodised and fabricated by Hydro Aluminium.
The use of Alphastrut has enabled the 100 tonnes weight saving requirement to be exceeded. Alphastrut is now being used to replace both steel and stainless steel support systems throughout the project, including window supports and fire hose cabinets.
