New UK Specification for Micro Trenching to Help Broadband

The UK Department for Transport (DfT) has today published the 4th Edition of their ‘Specification for the Reinstatement of Openings in Highways‘ (SROH), which might not sound particularly sexy but if you’re a civil engineer deploying “full fibre” (FTTP) broadband then the new specification for Micro Trenching will be of interest.

The use of Micro Trenching (aka – slot cutting) is nothing particularly new in the field of telecoms related civil engineering (we’ve seen it used before by several operators), although it hasn’t always had the benefit of a solidly agreed standard in the UK to help facilitate its use. Scotland moved to correct for this last year (here) and the UK DfT has now added the practice to their own SROH guidance.

In this approach ducts or cables can be laid into a thin slot-cut trench up to 60mm wide, which is significantly quicker, cheaper (less materials / machinery required) and generally more environmentally friendly than traditional trenching. The SROH change also means that “micro trenches cannot be unreasonably withheld by any authority and may only be denied in high duty or high amenity areas or for engineering reasons” (safety etc.).

Generally anyone who carries out street works must reinstate the street once that work is finished, in line with the SROH standards. The latest 4th Edition is an official replacement for the 2010 3rd addition and will be fully implemented as statutory guidance on 10th May 2021. Until then civil engineers can either continue using the 3rd Edition or seek agreement from the relevant local highway authority to use the 4th.

Main Changes to the 4th Edition

– The introduction of new materials to aid compliance with air voids (compaction) requirements.

– Rationalising the process for introducing innovation, the guidance is more open to innovation to improve the introduction of new materials and methods in street works.

– A new specification for micro trenching, crucial for the economic roll-out of broadband but only previously allowed by agreement with each local authority.

– Permitting the use of large diameter coring, which can reduce a week’s site occupation to around a day but previously was only allowed by agreement with each local authority.

The SROH 4th Edition (PDF)
https://assets.publishing.service.gov.uk/../sroh-fourth-edition.pdf