Your browser is no longer supported

For the best possible experience using our website we recommend you upgrade to a newer version or another browser.

Your browser appears to have cookies disabled. For the best experience of this website, please enable cookies in your browser

We'll assume we have your consent to use cookies, for example so you won't need to log in each time you visit our site.
Learn more

HEX lessons


Since first reading about the Heathrow Express tunnel collapse, there have been references to elaborate monitoring equipment and virtually ignored readings.

I understand the reason there were no injuries or fatalities was not because of the equipment but a 'mark 1 eyeball', ie an experienced workman, who noticed untoward movements in the excavation just in time to get everybody out.

There is no point in installing monitoring unless a chain of command or plan of action is set out which ensures that: (a) the results are seen by someone who understands the readings and their implications; and (b) someone has the authority to act upon the results, sufficiently quickly, if and when a hazard is identified. In this respect, simpler monitoring with readings that are understood may be better than elaborate monitoring that is not.

I think it was John Dunnicliff, a frequent contributor to Ground Engineering, who recommended the 'green-amber-red' approach to viewing and appraising the results of monitoring.

Eric Gray, Warwickshire

Have your say

You must sign in to make a comment

Please remember that the submission of any material is governed by our Terms and Conditions and by submitting material you confirm your agreement to these Terms and Conditions. Please note comments made online may also be published in the print edition of New Civil Engineer. Links may be included in your comments but HTML is not permitted.