| CONTENTS


9


Howard Street Tunnel upgrade nears completion Photo credit: CSX Transportation


Comment 5 12 16 24 30 33 Winter 2025 | 7 20


33 37


9 News REGULARS


Buyers’ Guide


48 50 Events


12 16 20


24 28 30


Projects Projects in US Updates on a range of key underground projects in the US, from coast to coast, including in New York, Virginia and California


Canadian advances Milestones met on some of the key transport and energy projects in Toronto, Montreal, Vancouver, and more.


Latin focus Metro tunnel projects making key progress in Brazil, Chile and Panama.


International HS2 successes UK high-speed rail project HS2 enjoys major tunneling finishes and key successes.


Clock and Cost Despite technical wins on HS2,


time and cost performance on the giant project has been under review.


Utilities - grid boosts Spotlight on some European power cable tunnel projects in UK, Germany and Sweden.


Technical H&S


Compressed Air Author: Dr Donald Lamont Latest guidance on high pressure compressed air in tunneling is presented and discussed by a global authority in the field.


Rock Classification Family Tree of Systems Authors: G. H. Erharter, N. Bar, T. F. Hansen, S. Jain, T. Marcher


Review and discussion of the international distribution and development of Rock Mass Classification systems, giving an effective yet brief overview of their inter-relationships .


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53