Chiltern Rail Limited (Chiltern) is undertaking preliminary market engagement to support the planned replacement of its existing Trackside Acoustic Detection System (TADS). TADS has been used by Chiltern since 2015 to monitor the health and condition of axle bearings and other bogie mounted rotating components. TADS is a wayside system developed by “Transportation Technology Centre Inc” (TTCI) for the purpose of detecting defective railroad bearing prior to failure. This system uses microphone-based technology to collect the acoustic signature of each bearing on a passing train. This data is processed thorough a collection of algorithms to identify defective bearings. The resulting information is used to drive critical safety, business and operational decisions. TADS is becoming unreliable and has suffered several outages more recently therefore Chiltern is seeking information from the market regarding potential solutions and delivery approaches for its replacement. The scope of requirement may include: • System design and Network Rail approval. • Decommissioning existing equipment and making the site safe. • Civil engineering where required for the new equipment. • Instillation of new equipment. • User interface/software package. • Ongoing maintenance and support. Further requirements are detailed within the draft specifications included within the documents provided. The purpose of this RFI is to: • Understand the solutions and delivery models currently available in the market; • Determine whether the requirement is best delivered through lots or separate procurements; • Test and refine the draft functional and non-functional requirements; • Understand implementation; • Obtain indicative pricing and commercial information; • Identify likely implementation timescales, dependencies and risks. The estimated contract value, contract duration and final procurement structure have not yet been determined. Suppliers are therefore being asked to provide information on available commercial models, indicative pricing, implementation timescales and the main factors affecting cost. This is preliminary market engagement only and does not constitute an invitation to tender or a commitment by Chiltern Railways to commence a future procurement. The purpose is to help Chiltern understand market capability and develop its requirements, commercial approach and procurement strategy, which is consistent with the intended function of preliminary market engagement under the Procurement Act 2023.