The behaviour of existing cast iron tunnels subjected to ground movements induced by new tunnelling works, is a much discussed topic. In many cases, new tunnels in highly populated urban cities like London will need to be constructed underneath a dense network of existing tunnels to avoid them. The construction of new tunnels, however, inevitably results in ground deformations that are transmitted to adjacent existing structures. The response of existing cast iron tunnels to tunnelling-induced deformation is not well understood and practicing engineers are faced with significant uncertainties about their response. This paper presents a case study in which multiple monitoring technologies have been deployed in a section at an existing cast iron tunnel in London underneath which a new, much larger tunnel is being constructed. The new tunnel is being excavated parallel with, and directly below the existing tunnel for a length of approximately 100 m. Instrumentation technologies deployed in a 40 m long section within the 100 m zone include analogue linear displacement transducers, fibre optics, digital tilt sensors, Video Extensometry and Digital Image Correlation, laser scanning and photogrammetry. The multi-technology deployments in this case study are presented in a unified dashboard system specifically developed for this project and provide an ideal scenario to investigate the detailed cast iron tunnel response using independent data sets. They also provide an exceptional opportunity, within the dashboard system, to use these data sets to understand the capabilities of the associated technologies when compared and contrasted against each other. The dashboard system can provide practicing engineers with the ability to understand tunnels' response accurately and rapidly and hence potentially provide significant time and cost savings for complex infrastructure projects. 293Tunneling and Underground Construction GSP 242

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