Following an inspection a decade ago, the Welsh Office was advised to reduce the allowable loading limit on the Menai Bridge in North Wales (built in 1826) from 32 to 7.5 tons. In an effort to help determine future load limits and the most effective means of strengthening the bridge, Laing Technology used a CR10 data logger to record data from strain gauges, thermocouples, and load cells. Laing had to replace 25 of the hangers that link the deck to the suspension chain. Before removal, the load in each hanger was measured so that the replacement hanger was stressed to exactly the same load. Following these repairs, the CR10 helped show that the bridge was strong enough to operate at the 32 ton capacity. In fact, it is now cleared for 40 ton GVW.

Case Study Summary

Application

System documents improved health of historic bridge

Location

North Wales

Products Used

CR10 

Contributors

Laing Technology, Campbell Scientific Ltd

Measured Parameters

Strain, temperature, load