The Thames Tunnel is a tunnel beneath the River Thames in London, connecting Rotherhithe and Wapping. It measures 35 ft wide by 20 ft high and is 1,300 ft long, running at a depth of 75 ft below the river surface measured at high tide. It is the first tunnel known to have been constructed successfully underneath a navigable river. It was built between 1825 …The Thames Tunnel is a tunnel beneath the River Thames in London, connecting Rotherhithe and Wapping. It measures 35 ft wide by 20 ft high and is 1,300 ft long, running at a depth of 75 ft below the river surface measured at high tide. It is the first tunnel known to have been constructed successfully underneath a navigable river. It was built between 1825 and 1843 by Marc Brunel, and his son, Isambard, using the tunnelling shield newly invented by the elder Brunel and Thomas Cochrane.