Inspections and surveys of dry open voids-Prometheus R&D

There are over 5000 recorded and numerous other unrecorded locations across the network where shallow mine workings may constitute a risk to the operation of the railway. The primary risk relates to the collapse of shallow workings causing subsidence at the surface that has the potential to damage railway assets including track possibly resulting in derailment. To manage the risks posed by shallow mine workings it is necessary to understand both the extent and condition of the workings. Only a small percentage of the shallow mine workings can be accessed, inspected and surveyed by suitably qualified engineers, the remainder are inaccessible or too dangerous. There are a limited number of techniques available to investigate those mine workings that cannot be accessed including geophysical methods and the drilling of multiple boreholes at each location, these have the following disadvantages: 1. Geophysical techniques rarely give reliable results in a railway environment, gaining access to track requires expensive possessions 2. The drilling of boreholes has the following challenges; • The process can be expensive, labour intensive and time consuming; • There can be difficulties gaining access near or on the operational railway; • The drilling of boreholes can initiate the collapse of mine workings; • The data obtained is limited to the borehole location and not the wider workings; • Interpretation of results can be very subjective. The first phase of the project saw Network Rail work with a consortium of small-to-medium sized enterprises and universities to develop the Prometheus drone to Rail Industry Readiness Level (RIRL) 3. The key motivation for this second-phase project is to develop a solution to RIRL6 that enables for these challenging sites to be inspected and surveyed through safer and more automated methods, by eliminating the need for human-entry. Network Rail would like to invite prospective suppliers to submit a Request for Information (RFI) Submission Template, which addresses this challenge statement. Network Rail would also like to understand indicative costs in delivering a product trial. Network Rail reserves the rights to hold discussions with Suppliers, following a response to this RFI.