As anyone who lives or works in SE16 know, at rush hour and particularly Monday to Friday between 08:00 and 09:00 and 16:30 and 18:30, Jamaica Road and Lower Road (A200) hold long queues of traffic waiting to cross the Thames using the Rotherhithe Tunnel. Drivers use many SE16 side street rat runs putting pressure on the neighbouring communities and the level of pollution at curb level is very high with so many idling vehicles. In March 2013, Jamaica Road hit national headlines as the slowest road in Britain with RAM Tracking reporting vehicles moving less than 0.08mph in the morning rush hour.

Rotherhithe Tunnel southern entrance 1909 and 2006 by Fin Fahey CC FlickrThe problem is mostly caused by the Edwardian legacy of Rotherhithe Tunnel. (This is not the famed Thames Tunnel built by  Marc Isambard Brunel and opened in 1843 which is nearby; this tunnel is now used by TfL Overground.) After years of mass opposition, the Thames Tunnel (Rotherhithe and Ratcliffe) Act 1900 authorised the tunnel to be built and 3,000 people lost their homes. Designed by Sir Maurice Fitzmaurice (1861-1924) chief engineer to the London County Council, the tunnel was built between 1904 and 1908 by Price and Reeves using a combination of cut and cover (at the entrances) and tunnelling shield excavation (for the main bore). Four shafts were sunk for access and ventilation, two of which (2 and 3) were fitted with spiral staircases for pedestrians. The tunnel cost £1M and was opened by George, Prince of Wales (later King George V) and the chair of the London County Council Richard Robinson on 12 June 1908. The opening is commemorated by a plaque over the tunnel entrance at each end.

The tunnel was naturally built to meet the needs of the transport of the time, mostly horse-drawn vehicles, early cars and many pedestrians. It was built as a single-bore, two-way carriageway of 1,481m in length, each lane only 2.4 m wide, footpaths only 1.2-2m wide and with 1:36 gradients at each end. Right-angle bends were included where the tunnel passes under the river bed to avoid docks on each side and prevent horses seeing daylight and bolting for the exit. To allow for large vessels to pass overhead, the tunnel is 14.5m below Thames high-water. The primary construction is a 9.35m diameter cast-iron lining formed from bolted segments; the entrance arches are the cutting edges of the original tunnelling shield. This is finished with glazed tiles on a concrete backing, laid in a bonded pattern. The cut and cover sections at each end have the same bonded pattern but the tiles are replaced with glazed bricks. The tunnel remains the largest iron-lined subaqueous tunnel in the world.

Rotherhithe Tunnel shaft by grahamc99 CC FlickrFrom the first the tunnel was a great success. Soon after opening 2,600 vehicles were using it each day, clearly justifying the LCC’s investment. Many working people were able to seek work across the Thames for the first time using the tunnel as a pedestrian route. The numbers of vehicles using the tunnel daily steadily rose and as a result, mechanical ventilation was introduced to vents 1 and 4 in the 1930s. The volume of traffic has continued to increase so that numbers now exceed 40,000 per day with another 20 pedestrians and 40 cyclists braving the journey each day too.

Safety has always been at the heart of the Rotherhithe Tunnel design and management – if not at it’s initial build! As a result, the tunnel is closed each Monday night 22:00-05:00 for routine maintenance; this weekly closure allows for testing emergency equipment, changing lighting units, cleaning the tunnel lining, replacing loose, damaged and discoloured tiles, sweeping the carriageway and footways, structural inspections and emergency repairs. . In March 2013, TfL introduced a width restriction of 6’6″ to both ends of the tunnel requiring vehicles over the limit to go by another route and slowing traffic entering the tunnel still further. After immediate outcry, TfL took away the vehicle posts the next day. The width restriction is to prevent collisions particularly at the narrow corners. Fire in the Rotherhithe Tunnel is very dangerous due to the construction without adequate means of ventilating smoke and the close reflecting walls intensifying the heat. Traffic using the tunnel is also limited to 20mph for the same reason. Lighting in the tunnel was once only mounted over the footpath but in 1982, these were replaced with a central lighting system.

Its proximity to the river makes the tunnel vulnerable to flooding which happened in 1928. In 1939 as part of the Air Raid Precautions, a floodgate was erected in Shaft 1 in Brunel Road. The installation included the provision of a crash and floodwall in the sub-tunnel beneath the gate. The floodgate is intended to protect the Overground and low lying area south of the tunnel from the effects from flooding, should the tunnel be breached. Now however Rotherhithe Tunnel is well defended and managed. A survey in 2003 rated the Rotherhithe Tunnel the tenth most dangerous tunnel in the whole of Europe due to its poor safety features. There are now however 9 CCTV cameras monitored by police (100% coverage, 24hour monitoring), air monitoring (CO and heat detection) and emergency points (fire hose positions, fire extinguishers and emergency telephones).

For more on the Rotherhithe Tunnel, see Dr Amanda Squires Centenary history on the Southwark Council’s website here