Highways

M25 Manhole Bay Replacements

TAG has been part of the M25 Maintenance framework for four years, working alongside main contractors including Skanska, Osborne and Jackson. This particular scheme called for the replacement of six PQ concrete bays with manhole accesses built into them, work that had to run on Saturday nights between 23:00 and 06:00, a working window of just seven hours before the carriageway had to reopen.

Given how little margin that window left, TAG carried out detailed trials with Skanska ahead of the main works to prove the sequence would hold up. Each bay was lifted out by vacuum method and removed from site, the steel reinforcement placed, the manhole access frame and cover reinstated, and a rapid-setting concrete poured around it, cured inside covered, temperature-controlled tents.

The scheme ran through genuinely challenging cold conditions, and the combination of thorough pre-shift preparation and an experienced site team meant every weekend closure went without issue. The road reopened to the public on schedule each time, with the manhole accesses reinstated to full working order.

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