Sandwich Plate System, SPS, was used in the Water Street bridge restoration in St Mary’s, Ontario, Canada following two years of closure due to safety concerns.

The 118-year old structure needed a new lightweight deck to match the expected life of the load-restricted trusses. The Water Street Bridge is a seven panel pin-connected Pratt through truss bridge, a quite rare pin-connected structure and specific to the area. With a load limit of 5 tons that was routinely ignored and salt water ingress due to winter salting, the super-structure was being destroyed. The existing deck was asphalt over wood.

SPS was chosen to improve the structural integrity and increase the longevity of the bridge while maintaining the historical look and feel of the bridge.

In order to for the bridge restoration to commence, the existing decks, sidewalks, stringers and beams were removed and the original abutments were reused.  The remaining super-structure was then repaired and repainted.  New stringers were predrilled to match the hole pattern of the SPS deck.

Weighing 22 tons, the whole bridge deck was delivered to site in one truck load and included nine SPS panels to cover 151.4 m² [1629 ft²]. For comparison, two or possibly even three trucks would have been required for a concrete delivery.

One crane operator and four additional ground crew were able to:

  • erect the panels in one day;
  • bolt the structure together in three days;
  • and weld it in two days.
  • Small lightweight crane was used.

The finished photos above were taken six years later, in 2022.

For the most up to date information about our groundbreaking technology, please follow the SPS Technology LinkedIn page.  And subscribe to the SPS Technology YouTube channel to see more about how the system works.