Britomart Rail Tunnel
Intumescent Coating Replacement

Deep inside the Britomart rail tunnel, the intumescent coating protecting the structural steel had simply reached the end of its working life, and replacing it meant operating in one of the more constrained environments BlastOff works in: a live rail corridor with strict access windows and no tolerance for contaminating the tunnel around live services. There was no scope to shut the corridor down for an extended period, so the method chosen had to fit inside the access BlastOff was given and leave nothing behind in the tunnel when the work stopped for the day.

BlastOff vacuum blasted the aged intumescent coating from the structural steel, chosen specifically for its full dust and debris recovery in an enclosed setting where nothing could be allowed to drift or settle beyond the work area. With the steel stripped back to a sound condition, a new intumescent fire protection system was applied to the specified thickness, verified with dry film thickness measurements to confirm the coating met the required build rather than relying on visual judgement alone. That combination, contained removal followed by a measured, verified application, is what let the fire rating be restored without contaminating the tunnel environment or disrupting the rail services running through the corridor during the works.

Any asset owner managing ageing intumescent systems in an enclosed or access-restricted environment, tunnels, plant rooms, basements, faces the same core question: how do you strip and recoat safely when the space cannot be isolated for long. The answer starts with a removal method matched to the containment needs of the site, verified film thickness rather than assumed coverage, and a realistic access plan agreed with the asset owner before work begins, all of which sit within BlastOff’s protective coatings service.