NEWSLETTER

Structural integrity monitoring seems to be flavour of the month, with many new, and not a few established, companies starting to offer services in the field. In addition a number of collaborative networks have been established to encourage the sharing of best practice both within and across traditional sector divides. This may lead the casual observer to think that structural integrity monitoring is a new idea. Nevertheless, structural integrity monitoring is not new, it has been around since structures were first constructed and, at least in respect of civil engineering structures in the railway industry, has been formally documented for many years. What is new and exciting is the development of new techniques which can enable monitoring to be undertaken in real time from remote locations.

Railway structural examinations have traditionally been undertaken by suitably trained examiners visiting a structure at a pre-determined interval and reporting what they are able to see. This report is then examined by an engineer and decisions made on whether maintenance is necessary. It is fairly evident that the current system has stood the test of time, since few bridges fail in service, although maintenance may not have been carried out in the most efficient manner. Obviously a report that a structure is in good condition requires little thought about future action as does, at the opposite end of the scale, a report indicating that a structure is in urgent need of replacement.

The down side of this system is that, with a Railtrack asset portfolio of over 40,000 bridges and numerous other structures, these processes generate vast quantities of paper. Hence the ability to remotely monitor assets in service appears to be very attractive, particularly as the data can be stored by computer. However real time monitoring, unless properly managed, will also produce large quantities of data which will give an asset owner similar problems to those created by the present system.

Given these data handling concerns, it is most likely that advanced structural integrity monitoring will not, at least in the foreseeable future, be deployed widely across a network such as Railtrack's. I believe that these techniques will be used to supplement the current examination system when that shows that the correct future course of action is unclear, or where hidden faults are suspected. Monitoring is also likely to be used to verify that the in service performance of prototype applications of novel materials and repair techniques corresponds with the design theory. A further possible use of monitoring is to target routine maintenance of small but important components on a "just in time" basis.

Railtrack, along with most other major asset owners, will continue to monitor developments in the field of structural integrity monitoring and will utilise those which demonstrate a real benefit over more traditional methods. In making advances in this field, researchers must be aware that their inventions will be used in remote areas and in all weather conditions. For them to be of use to an asset owner, the end result should be a self contained black box, capable of being used by non specialists and which gives a red light or a green light at the end of its sampling process.