Dear Sir
I was pleased to see the article by Andrew Marshall in the July edition of T&TI (p19) highlighting the HSE/PJA/BTS publication “Guidance for Designers – Internal dimensions for pipejacks and tunnels below 3m diameter and indicative drive lengths”.
However I felt that the article’s headline “HSE restrictions on hand tunnelling” was unduly sensationalist and inaccurate, in that it did not properly reflect the content of what was an informative and balanced review of the document.
To HSE the main purpose of the document is set out in the first three words of its title – “Guidance for designers”. This publication was a response to concern by PJA members on how to respond to designers and clients on occasions when they were asked to tender for the construction of pipejacks and tunnels of smaller diameters than those which they considered to be safe or which required extensive hand excavation. The tables were agreed in discussions between HSE and PJA followed by consultation with the BTS.
There is some flexibility in the Guidance for designers to use their professional discretion in determining drive lengths but HSE expects designers generally to adhere to “acceptable” criteria.
Yours faithfully
Donald R Lamont
HM Principal Specialist Inspector
Construction Division Technology Unit
HSE, Bootle
