Scotland Seek Narrow Trenching Standard for Broadband Rollout

The Scottish Government is consulting on changes to Section 130 of the New Road & Street Works Act 1991, which seeks to create a uniform technical standard for “narrow trenching“. This could encourage greater use of the technique by broadband network builders and better safeguards across Scotland’s 33 road authorities.

Narrow trenching is already being used by a number of civil engineering contractors, such as the John Henry Group (JHG), in order to deploy fibre optic broadband ISP cables across parts of the United Kingdom. For example, Virgin Media and JHG have used it to reduce their normal trench size from around 40cm to just 10cm. Gigaclear has done a related video on this method.

The idea here is a simple enough because by digging a smaller trench you make it both faster and cheaper to deploy new cables. All of this is useful because the Scottish Government’s £600m R100 project is aiming to deliver 100% coverage of “superfast broadband” (30Mbps+) across Scotland by the end of 2021 (currently still in procurement here and here).

However Scotland is concerned that this method lacks a “consistent approach” (needed to ensure that there are “sufficient safeguards” in place to protect the existing road network as an asset) and isn’t being as widely used as it could be. The existing code merely defines it as “all trenches of 300mm surface width or less, with a surface area greater than two square metres” and says this can be used in the carriageway, footway or verge.

While this technique can be used under the existing code, no single section directly deals with this method. “This leaves the prescribed requirements difficult to assess and open to different interpretations,” said the SG’s new consultation. Introducing a new section, which pulls together all of the necessary requirements, might provide some much needed clarity on the subject.

Without sufficiently clear safeguards there is also a potential for damage to the road surface as an asset. “Although there are clear benefits to narrow trenching in terms of speed of delivery and therefore cost to the organisation, it is recognised that this cannot be at the expense of the road as a maintainable asset.”

In addition, both “Slot cutting” and “Micro trenching” are entirely precluded by the code. These terms have seen an increase in use in the rest of the UK without an agreed definition. This has led to the terms being used as both an alternate term for narrow trenching and as separate excavation techniques which lie outside of the Specification for the Reinstatement of Openings in Roads 2015 (SROR) code.

Michael Matheson, Scottish Cabinet Secretary for Transport, said:

“We are all reliant, to some extent, on the range of services provided by the telecoms, electricity, gas and water industries. I’m sure that it won’t have escaped your attention that a lot of work is being undertaken to ensure that every home and business has access to superfast broadband. The Scottish Government is committed to ensuring this happens by the end of 2021.

Utility companies operate in a competitive market. They are continually looking for ways to improve efficiency and reduce costs to keep ahead of their competitors. This includes looking at new methods to improve the rollout of services. One of these is narrow trenching. While this technique can offer many advantages over traditional methods, a consistent approach is required to ensure that there are sufficient safeguards in place to protect the existing road network as an asset.

The Scottish Government is launching this consultation to seek your views on which technical parameters should be applied to “narrow trenching” to help ensure this method is carried out consistently across all of Scotland’s 33 road authorities for the benefit of our road network, the other utility apparatus already placed under our roads and pavements, and ultimately for the benefit of the people of Scotland either as road users or service users.”

The consultation will remain open until 7th December 2018. Credits to one of our readers, Marc, for spotting this development.