Callender-Hamilton truss bridges

Engineering Work (eg road, bridge, sawmill, dam)


The Callender-Hamilton truss bridge was regarded as the most economical bridge of its time and was created by New Zealander Archibald Milne Hamilton (1898–1972).

Hamilton was born in Waimate, South Canterbury, and he graduated with a Bachelor of Engineering (Civil) degree from Canterbury College (now the University of Canterbury) in 1924.

Hamilton first developed his bridge design in 1927 in Iraq, where he was working as their Public Works Department’s Assistant Engineer. Until 1932 he directed the construction of Rowanduz Road, a strategic route requiring many engineering feats, and it was during this project that the Callender-Hamilton truss bridge was born. On his return to London, England, Hamilton developed the idea further and it was patented in 1935.

The multi-truss multi-tier bridge system that he developed, known as the Callender-Hamilton bridge, allowed faster than normal construction by unskilled technicians due to its prefabricated components. This bridging technique later proved to be extremely effective and was used in the development of military bridging prior to and during World War Two.

Callender-Hamilton truss bridge in New Zealand
Over 1000 Callender-Hamilton bridges exist worldwide, across 50 countries. There are at least 16 bridges located in New Zealand. The known remaining bridges are all on South Island State Highways (SH).

This type of bridge was used by the Ministry of Works from the mid 1950s because the galvanised steel construction meant low maintenance cost and the standard design also allowed for simple construction and ease of transport. Callender-Hamilton bridges were perfect for Westland which was still quite isolated at the time and has high rainfall.

Remaining New Zealand Callender-Hamilton bridges include (north to south):

  • Pelorus River, SH6
  • Mokihinui River, SH67
  • Wallace Point, SH73
  • Parkers Creek, SH6
  • Windbag Creek, SH6
  • Haast River, SH6
  • Greenstone Creek, SH6
  • Harris Creek, SH6
  • Cron Creek, SH6
  • Roaring Swine, SH6
  • Cache Creek, SH6
  • Haast River - Pleasant Flat, SH6
  • Gates of Haast, SH6
  • Tutoko River, SH94
  • Donne River, SH94
  • Gulliver River, SH94


William M Baker, Nicholas D Molcsan and Andrew H Buchanan, ‘Callender-Hamilton Truss Bridges: The New Zealand History,’ paper presented at the 4th Australasian Engineering Heritage Conference (2014). See attachment below.


Baker, Molcsan and Buchanan paper (380 KB).pdf


See list of bridge above.

Marlborough, Nelson Bays, West Coast/Buller

Access Info

Nature of Engineering
Infrastructure (incl. Road, water, ports), New Zealand Innovations


Pelorus Bridge, November 2014. IPENZ

(Click image to enlarge )