Steel Bolt-A-Plate® Culvert

An economical alternative to concrete culvert structures or traditional beam bridges, Steel Bolt-A-Plate® is perfect for smaller buried arch bridge applications and should be the product of choice for its lightweight strength and versatility.

Available in a wide range of shapes and sizes, it is ideal for economical buried arch bridge​ and drainage pipe construction, as well as many other bridge construction and culvert pipe applications in the transportation, public works, mining (tunnel portals), railway, residential development (motor vehicle and pedestrian underpasses), agriculture (stock underpasses), forestry and winemaking sectors.

Steel Bolt-A-Plate® is also an economical, lightweight and strong ​truss bridge​ alternative. Frequently used as more economical alternatives to traditional beam bridges or truss bridges, open-bottom buried arch bridges offer improved hydraulic flow, help counter erosion and preserve natural streambeds.

Easy installation

The ease of installation of Steel Bolt-A-Plate® culverts offers very real benefits to specifiers in both normal and difficult situations. The easily handled corrugated plate system can be erected on-site - an ideal solution for remote areas where access is difficult - or delivered to site fully assembled if access and transport regulations allow and where fast job completion is vital. Steel Bolt-A-Plate® culverts derive their strength through the interaction of the surrounding backfill.

Note:CSP’s Steel Bolt-A-Plate® is not a stocked item. A lead time for manufacture can be provided following the design and consultation process.

Please contact Steve Silby for more information:
Steve Silby – National Specification Manager

+64 27 327 7985

  • Cost-efficient and convenient culvert option
  • Easy to ship and install for remote locations
  • Long-lasting and virtually maintenance-free
  • Bottomless designs are more environmentally friendly
  • Available with a variety of footing and headwall/wingwall options
  • Can re-line older structures
  • Available with tested and approved protective coating systems-BestKote®
  • Culverts are designed by Project Engineers however CSP can review the structural design and issue a Producer Statement PS2 (Design Review)
  • Fast economic job completion.
  • Simple assembly – please note the project requires engineering supervision and the backfilling of the structure requires skill and experience
  • Low equipment costs for assembly
  • Pre-assembly reduces the inconvenience and cost to maintain existing services
  • Designed and manufactured to National Standards ISO 9001
  • Hot-dip-galvanised, corrugated structural steel plate for smaller applications
  • Spans of 1.5 to 10m
  • Corrugation profile of 152.4 mm pitch x 51 mm depth
  • Available in: Standard, Low or High Profile Arches; Rounds; Ellipses and Box Structures

Note: Design and supervision should be conducted by an experienced engineer. The site engineer is to ensure that assumptions made at the design stage are present on-site and that backfilling is in accordance with the specification.


Design, manufacture and Installation requirements for Steel Bolt-A-Plate® are specified in AS/NZS 2041: Buried Corrugated Metal structures. This is a joint Australian and New Zealand Standard and has several parts. Those applicable to Steel Bolt-A-Plate® are as follows:

  • AS/NZS 2041.1:2011 Buried Corrugated Metal Structures - Part 1 Design Methods
  • AS/NZS 2041.2:2011 Buried Corrugated Metal Structures - Part 2 Installation Methods
  • AS/NZS 2041.6:2011 Buried Corrugated Metal Structures - Part 6 Bolted Plate Structures