The main construction of HS2, Britain’s high-speed rail network, began in September 2020 when Main Works Civils Contractors moved from enabling works, scheme design and preparatory work to full construction of the railway. The low-carbon network will link London and the West Midlands and extend services to the North and Scotland, serving more than 25 stations. High-speed trains will reach speeds of 225mph and transform journey times. This volume of High Speed Two: Infrastructure Design and Construction from the HS2 Project, contains a collection of papers submitted to HS2 Ltd’s Technical Papers Competition. Contributions have come from consultants, contractors, suppliers and third-party stakeholders involved in developing the planned infrastructure of the HS2 project. As part of HS2’s Learning Legacy commitment, the organisation seeks to share its learnings and best practices with the rest of the industry throughout the project lifecycle. This volume offers high-quality papers on the best practice in planning, design, construction and management for large-scale railway infrastructure projects. For more papers from HS2 Ltd’s Technical Papers Competition, please see High Speed Two (HS2): Infrastructure Design and Construction (Volume 2) , the companion to this volume.