Trussed Metal Bridges

Our log bridges only have an effective span of 10 metres. Longer spans can be accommodated by joining the bridge on a pier or by the use of the laminated log bridge for spans up to 15 metres. Unfortunately, the laminated log bridge was seen by some customers as too rustic for many applications and the demand for longer spans continued to grow.

Considerable research went into this design, looking first at timber and then various designs in both steel and aluminium. While structural integrity was important, the bridge had to be aesthetically pleasing and capable of containerisation and road transport without the need for long wide load.

We finally settled on the Warren truss design. In November 1997 we produced our first trussed bridge, a 16 m span for the Beaudesert Shire near Brisbane, Queensland.

Steel Footbridges Bridges
OSA has developed a range of steel bridges to meet the variety of applications. (A 1.7MB PDF file.)

See examples of our bridges from our Bridge Project Galleries

Handrail Options

Steel
A galvanised rail is available in either pedestrian or bikeway compliant bridges. The balustrade are solid 16mm diameter bar to meet the lateral load requirements of the bridge code. They are also very resistant to vandalism.

Timber
The top and bottom handrails are in spotted gum and their profile is based on our standard handrail design except with a heavier bottom rail. The slats are 42x35mm and spaced at 120mm. The handrails are painted with Ameron Weathershield gloss over an oil based primer. The decking is Outdoor Structures Deckwood which has been pre-oiled.

The bridge can be painted to the customer's requirements except that the timber must be painted a light shade.

Finish

Our trusses are available in steel which are primed with an Inorganic Zinc primer topcoated with Ameron PSX 700, a new generation environmentally friendly finish which its manufacturers claim will give.

• Surface protection equal to galvanising
• 58% gloss retention after 12 years
• Easy graffiti removal

Design Standards

The bridge fully complies with the Ausroads Bridge Design Code, AS 1720 - Timber design Code and AS4100 - Steel Structures Code. The Design Live Load is 5kPa (equivalent to 5 persons/m2) with a Load Factor of 2.0.

Some basic design information is:

• Maximum span 26 metres
• Module is 2 metres
• Pre-cambered 1 in 100
• Bridge length classified as centre to centre of bearings
• Overall bridge length is 500mm longer
• Bridges can be spliced for export

Because of the large spans that can be encountered we do not provide standard footing details as we do with our log bridges. If a soil test is supplied we can provide footing details at an extra cost. If the footing design is arranged by the client we provide outline drawings for the footings.

Go to T44 Vehicle Bridges