This is a PhD Thesis by portfolio and is the output of research, development and the practical application of processes for railway track asset management in the UK between 2004 and 2013 and the subsequent development of innovative solutions. There are two major sections to the portfolio; firstly the background, literature review and development phases; and secondly two specific projects. The projects consisted of major works on the UK West Coast Main Line and targeted schemes involving Eurostar and Humberside. The author is a chartered civil engineer and has spent the whole of his career (32 years) in railway civil engineering mainly in design, maintenance and management and culminating in undergraduate and postgraduate teaching. Railway Infrastructure Life Extension is a specialist area that has not been studied before in this depth and was initially related to specific problem solving. However, it is now clearly accepted that UK railway privatisation was a success and after passenger journeys increased by 80% in the period 1996 to 2012, there was substantial strain upon the infrastructure. This portfolio is informed by and considers the current and future challenges faced by railways from a safety, performance and efficiency angle. The study is supported as strategically important work being entirely appropriate and relevant to the industry by the two sponsors, Dr Ilias Oraifige, Senior Academic and Reader at the University of Derby and Ken Mee, Managing Director of Quality and Safety Services Ltd. The term “life extension” was uniquely created and applied to railway infrastructure by the author and his teams during the early phases of this project and became the industry standard phrase for the work involved. The historical background and literature review of the research is included to enable the reader to understand the context of the work undertaken previously where the author acted as the major driver behind the work under industrial conditions commencing in 1997. The author has had a direct involvement in the practical application of the techniques and processes through various senior positions in the UK Rail Industry. The work resulted in testing of equipment in live locations including quantifiable risk assessments and actual benefits to safety, economics and performance. The author held a number of key roles relevant to the study. From 1995 – 2000 he was Regional Director of Balfour Beatty Rail Maintenance and set up the Central Maintenance Group at Sandiacre, Nottinghamshire. This was a team of engineers, supervisors and staff employed to carry out heavy maintenance principally on the Erewash Valley line. From 2000 – 2003 he was Engineering Adviser to the Rail Regulator where he was appointed as the government representative on the Hatfield Recovery Board and sat on various working committees including the Wheel Rail Interface System Authority (WRISA). This was a significant contribution to the recovery of the UK rail system to normal working following the Hatfield Accident. A key contribution during this time was the understanding of the impact of track quality upon asset deterioration. From 2004 – 2007, the author, in his role as General Manager of Carillion Rail Ancillary Projects, was commissioned to set up an organisation to develop and provide innovative and original solutions for life extension and refurbishment of railway track systems in the UK. The principle objective was to build upon previous work done during the final years of the UK contracted-out railway infrastructure maintenance term contracts. The innovations chosen for development were related to delivering economic access to facilitate heavy maintenance and the development of new techniques to extend track life. A number of projects and case studies and their specific solutions are identified and reviewed. Of particular strategic importance is the use of the “Railvac” Swedish ballast removal machine developed in the UK between 2004 and 2012. The culmination of the work is the incorporation of the principles and ideas into the UK National Policy under the ongoing strategy approved by the Office of Rail Regulation for 2014-2019. The author has published a number of papers in support of the thesis which have been presented at conferences in London and Spain.