In August 2014 the main Tunnel near Barclays Bank was repaired by the Swedish Construction Company SKANSKA. The road was dug up to expose the Tunnel for the first time in 160 years. The problem they had to deal with was the re-routing of a 3 phase electrical cable that had been chopped into the roof of the Tunnel. This was done, date unknown, by cutting out bricks across the roof of the Tunnel, thereby weakening the structure. A roof section, about 15ft long, was taken out completely and they drilled holes through the tunnel walls to accommodate the new route of the cable inside the tunnel. Shown in the slideshow below.
They put a new flexible wooden former underneath the cut-out section then reformed the arch using new engineering bricks, this was then covered with a cement patch. Gas pipes were also rerouted through the tunnel. When this was finished there was steel reinforcing mesh fixed over the top of the tunnel and concrete poured over the top of the mesh. Entombing the tunnel forever. The road was then reconstructed and resurfaced.
If you would like to see more photos of the 2014 repairs click this link