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Emley Moor Transmitter
Jagger Lane, Emley Moor, Kirklees, West Riding of Yorkshire, UK
associated engineer
British Insulated Callender's Cables
Ove Arup & Partners
date  1956, 1964, August 1969 - 1971
era  Modern  |  category  Telecommmunications  |  reference  SE221129
ICE reference number  HEW 15
The present Emley Moor Transmitter tower is the tallest free-standing structure in the UK and the third transmitter on the same spot. Its Pennine location was chosen to maximise the number of people to whom it could broadcast.
The first transmitter was built for the Independent Television Authority. The steel lattice pylon supported an aerial that transmitted VHF television signals eastwards. It was 135.6m high and operated from 3rd November 1956. The tower was dismantled and re-erected at Craigkelly, Fife, in 1971 to broadcast UHF signals.
The second was a cable stayed mast 385.6m high once the tallest in Europe. It had a column of 2.75m diameter steel cylinders 274.3m tall, topped by a 106.7m tall lattice section and a capping cylinder. Its primary purpose was to transmit UHF colour television signals, though it improved the VHF reception in some areas. The mast was designed by British Insulated Callender's Cables and was similar to one still standing at Belmont, Lincolnshire (built 1965).
The steel shell tended to ice over in cold weather, adding weight and creating a falling hazard on thawing. Strong winds and a thick coating of ice combined to make the mast oscillate and eventually collapse at about 5pm on 19th March 1969 fortunately nobody was killed or injured seriously but 6 million viewers lost their television pictures. To restore services, three temporary masts were erected 61m (23rd March), 204.2m (16th April) and 91.4m tall.
The Independent Television Authority sued both designer and contractor but settled out of court for 3.2m in 1983. Flint & Neill led the investigations into the cause of the collapse. Though most of the mast was destroyed, the remaining two undamaged sections were incorporated into the Race Officers' Tower of Huddersfield Sailing Club, where they remain.
Public safety concerns prompted a design change, so the third and present structure is a reinforced concrete tower designed by Ove Arup & Partners. The concrete shell is 274.3m tall, topped with a 55.7m high steel lattice mast carrying the aerials and a spiral wind deflector.
The tower has a curved taper and has a diameter of 24.4m at the base and 6.5m at the top. Wall thickness varies from 533mm to 350mm, bottom to top. The superstructure sits on a ring foundation 8.2m thick and 6.1m deep. The tower contains 7,000 cubic metres of concrete and weighs 11,200 tonnes.
There are two lifts inside the mostly empty tower, one gives access to all levels and the other travels directly to the microwave link room 274.3m above the ground a journey that takes seven minutes. Or there is an 865-rung ladder. At that height the control room can move with the wind, though the tower can withstand winds of up to 241km per hour.
The transmitter was completed in November 1970 with UHF (21st January) and VHF (21st April) services starting in 1971. It transmits signals over a 64km radius and is now one of the most powerful with outputs of 870kW analogue and up to 10kW digital. After digital switchover is completed, possibly by September 2011, the digital output will increase to 174kW.
External repairs were carried out via rope access in mid 2002. On 26th March 2003, the tower became a Grade II listed building. Aircraft warning lights were installed in July and August 2006. Emley Moor Transmitter is now owned by Arqiva and is not open to the public.
Cable-stayed mast (1964): EMI
Research: ECPK
bibliography
http://en.structurae.net
http://news.bbc.co.uk
http://tx.mb21.co.uk
www.aerialsandtv.com
www.nce.co.uk
www.thebigtower.com
reference sources   CEH North
Location

Emley Moor Transmitter