Nab Tower

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Nab Tower Lighthouse
Image of the Nab Tower after extensive repairs and alterations in 2012..JPG
Nab Tower is located in Greater Southampton
Nab Tower
LocationNab Rocks, near the Isle of Wight, England
Coordinates50°40′03″N 0°57′04″W / 50.66749733°N 0.951162862°W / 50.66749733; -0.951162862Coordinates: 50°40′03″N 0°57′04″W / 50.66749733°N 0.951162862°W / 50.66749733; -0.951162862[1]
Year first constructed1819 (established lightship)
Year first lit1918
Automated1983
Constructionsteel and concrete
Tower shapemassive cylindrical tower with a hexagonal lantern
Markings / patternunpainted tower, white light
Tower height17 m (56 ft)[2]
Focal height17 m (56 ft)
Current lensVega VRB-25 medium intensity rotating beacon
Intensity2,850 candela[3]
Range12 nmi (22 km)
CharacteristicFl W 10s.
Fog signal2 blasts every 30s. (range 2 nmi (3.7 km))
RaconEdit this on Wikidata
Admiralty numberA0780
NGA number1048
ARLHS numberENG 082
Managing agentTrinity House[4]

The Nab Tower was a tower planned for anti-submarine protection in the Solent in World War I. It was sunk over the Nab rocks east of the Isle of Wight to replace a lightship after the war, and is a well-known landmark for sailors as it marks the deep-water eastern entry into the Solent.

History[edit]

The Nab Tower prior to refurbishment

During the First World War, the British Admiralty designed eight towers codenamed M-N that were to be built and positioned in the Straits of Dover to protect allied merchant shipping from German U-boats. Designed by civilian Guy Maunsell, the towers were to be linked together with steel nets and armed with two 4-inch guns with the idea of closing the English Channel to enemy ships.

However, by the end of the war in 1918 only one such tower had been completed, at the time a cost of one million pounds, and was located at Shoreham Harbour, awaiting deployment. While another part-built tower would eventually be dismantled in 1924, there remained the completed 92-foot-tall (28 m) metal cylinder sitting on a raft of concrete.

In 1920 the completed tower was towed by two paddle-wheel tugs to the Nab rock, a rock in the deep-water approach to the eastern Solent and previously marked by a lightship. Buoyancy was provided by the honeycomb construction of the concrete base, creating 18 watertight compartments. When these were flooded, the structure sank and settled to rest at an angle of 3 degrees from vertical towards the northeast – a characteristic tilt which is obvious to this day.

Pre-1983 optic from the Nab Tower; one of a pair, now on display inside Hurst Castle.

In addition to the main navigation light, the tower initially displayed sector lights marking the man channel into Spithead.[5] A fog horn was also installed. It was manned as a lighthouse, but also functioned as a Royal Navy signal station;[5] during World War II it was equipped with a pair of Bofors guns to provide some defence to the Solent approach, and shot down several aircraft.[5] The Royal Navy withdrew its personnel from the tower some time after the war, but the tower remained under Ministry of Defence ownership until 1984, when Trinity House acquired the freehold.[6]

The Nab Tower still functions as a lighthouse, but since 1983 it has been unmanned. That year, a helicopter pad was constructed on the tower and a new pre-fabricated lantern-tower was installed containing an automated acetylene lamp.[5] In 1995 the light was converted to solar power operation and a new rotating beacon was installed in the lantern.[7]

In November 1999 the merchant freighter Dole America, carrying a cargo of bananas and pineapples, hit the Nab. The ship was badly damaged and only avoided sinking by being run aground. The base of the tower suffered superficial and internal damage. The damage was repaired in 2001.

The tower was featured as the main setting of the 1951 Hammer thriller, The Dark Light.

Major refurbishment in 2013[edit]

In 2013, Trinity House commissioned BAM Nuttall to undertake a major refurbishment programme due to extensive corrosion of the upper levels, meaning it was unsafe to land helicopters upon the helipad. The height of the tower was reduced, all external steel and cladding were removed and the existing concrete sub-structure was coated in a new layer of gun-applied concrete. On completion, new AIS and RACON beacons were fitted, along with a fixed main light with a 12 nautical mile range.[8]

The distinctive red lantern structure, removed as part of the refurbishment, is now on display at Hurst Castle,[9] along with a pair of rotating 4th-order dioptric optics, which were in use on the tower prior to automation.[10]

See also[edit]

References[edit]

  1. ^ Latitude
  2. ^ Nab Tower Lighthouse. Retrieved 3 May 2016
  3. ^ Nab Tower Lighthouse. Retrieved 3 May 2016
  4. ^ The Nab The Lighthouse Directory. University of North Carolina at Chapel Hill. Retrieved 3 May 2016
  5. ^ a b c d Woodman, Richard; Wilson, Jane (2002). The Lighthouses of Trinity House. Bradford-on-Avon, Wilts.: Thomas Reed. pp. 96–97.
  6. ^ Millyard, Simon (Summer 2014). "Nab Tower Engineering Works 2013 – 2014". Flash (21): 4–5. Retrieved 20 March 2019.
  7. ^ "Nab Tower Lighthouse". Trinity House.
  8. ^ "Renovation of Nab Tower lighthouse begins". Maritime Journal. Retrieved 12 December 2014.
  9. ^ "The Association of Lighthouse Keepers". Hurst Castle. Retrieved 20 March 2019.
  10. ^ "Photo". Alamy. Retrieved 20 March 2019.

External links[edit]