Emley Moor transmitting station

Arqiva Emley Moor Tower

Tower height	330.4 m (1,084 ft)
Coordinates	53°36′43″N 1°39′52″W / 53.6119°N 1.6644°W / 53.6119; -1.6644Coordinates: 53°36′43″N 1°39′52″W / 53.6119°N 1.6644°W / 53.6119; -1.6644
Grid reference	SE222128
Built	1969 - 1971
BBC region	BBC Yorkshire
ITV region	ITV Yorkshire
Local TV service	Made in Leeds

Emley Moor transmitting station is a telecommunications and broadcasting facility on Emley Moor, 1 mile (1.6 km) west of Emley, in Kirklees, West Yorkshire, England (national grid reference: SE2219712899). The station's most visible feature is its 1,084-foot (330.4 m) tall concrete tower, which is a Grade II listed building. It is the tallest freestanding structure in the United Kingdom,^[1] 7th tallest freestanding structure in the European Union, 4th tallest tower in the European Union, and 24th tallest tower in the world.

The tower's official name "Arqiva Tower" is shown on a sign beside the offices at the base of the tower but it is commonly known as "Emley Moor mast".

History

The tower is the third antenna support structure to have occupied the site. The original 135-metre (443 ft) lattice tower was erected in 1956 to provide Independent Television broadcasts to the Yorkshire area. It entered service on 3 November 1956, transmitting Granada TV programmes on weekdays and ABC TV programmes at weekends. It was replaced by a taller 385.5-metre (1,265 ft) guyed mast, identical to the structure at Belmont transmitting station in Lincolnshire in 1964. The dismantled lattice tower was rebuilt at Craigkelly transmitting station.

Mast collapse

Emley Moor has been a transmission site since the earliest days of TV. The first permanent transmitter built there was for ITV, covering much of the north of England. It had a 135-metre (443 ft) lattice tower, which provided limited coverage. Its performance was improved in anticipation of colour PAL transmissions in 1966, when a 385-metre (1,263 ft) guy-supported tubular mast was erected. It was constructed from curved steel segments to form a 2.75-metre (9 ft) diameter tube, 275 metres (902 ft) long and was surmounted by a lattice section 107 metres tall and a capping cylinder, bringing the total height to 386 metres (1,266 ft). At the time of its construction, it was one of the tallest standing structures in the world. It was designed by BICC and manufactured by EMI.

The cylindrical steel mast was regularly coated in ice during the winter months, and large icicles formed on the guy wires, placing them under great strain. During winter ice falling from the guy-wires was common. For this reason, red warning lights on the tower operated when ice was a hazard and notices were posted on the fence adjacent to Jagger Lane, below the guy wire crossings.

On 19 March 1969, a combination of strong winds and the weight of ice that had formed around the top of the mast and on the guy wires brought the structure down. The duty engineer wrote in the station's log book, demonstrating that failure of the structure was completely unexpected:

• Day: Lee, Caffell, Vander Byl
• Ice hazard - Packed ice beginning to fall from mast & stays. Roads close to station temporarily closed by Councils. Please notify councils when roads are safe (!)
• Pye monitor - no frame lock - V10 replaced (low ins). Monitor overheating due to fan choked up with dust- cleaned out, motor lubricated and fan blades reset.
• Evening :- Glendenning, Bottom, Redgrove
• 1,265 ft (386 m) Mast :- Fell down across Jagger Lane (corner of Common Lane) at 17:01:45. Police, I.T.A. HQ, R.O., etc., all notified.
• Mast Power Isolator :- Fuses removed & isolator locked in the "OFF" position. All isolators in basement feeding mast stump also switched off. Dehydrators & TXs switched off.

Wreckage of the Emley Moor Mast, which collapsed in March 1969, strewn across fields.

The collapse left sections of twisted mast strewn over the transmitter site and across the junction of Common Lane and Jagger Lane and the surrounding fields. Although a falling stay cable cut through a local church and across the transmitter site buildings, no one was injured. It completely disabled the BBC2 UHF transmitter and the ITV VHF transmitter, leaving several million people without service. BBC1 VHF television transmissions continued from Holme Moss. The ITA owned a collapsible emergency mast, 61 metres tall which was moved to Emley from the Lichfield transmitting station so that some service could be restored. ITV signals were restored to 2.5 million viewers within four days. The BBC provided a mobile mast on an outside broadcast van to restore a restricted BBC2 colour service within two days. The ITA bought a larger temporary mast from a Swedish company. A crew of Polish riggers was hired and a 204-metre mast was erected in under 28 days at a cost of £100,000. This mast could hold only one set of antennas, so many viewers in outlying areas still could not receive colour programmes. The taller mast was brought into service on 16 April. Some weeks later, the BBC erected a 91-metre (299 ft) mast, improving coverage.

The accumulation of ice was believed to have caused the collapse, but a committee of inquiry attributed it to a form of oscillation which occurred at a low but steady wind speed. Modifications including hanging 150 tons of steel chains within each structure were made to similar masts at Belmont and Winter Hill. None of the modified masts have collapsed.

After the temporary masts, erection of the current concrete tower began in 1969. UHF (625-line colour) transmissions commenced on 21 January 1971 and the older VHF (405-line black & white) system became operational on 21 April 1971. Local residents did not wish to see another mast on Emley Moor, and a departure from usual designs was called for. The new structure consists of a curved pillar, 275 m (902 ft) tall, constructed of reinforced concrete, topped by a 55-metre (180 ft) steel lattice mast which carries the antennas.

A section of the collapsed tower was converted for use as a racing control tower at Huddersfield Sailing Club.^[2]

Structure

The structure is a tapered, reinforced concrete tower. It is the tallest freestanding structure in the United Kingdom at a height of 1,084 feet (330 m). Reaching the tower room at the top of the concrete structure at 900 feet (274 m) involves a seven-minute journey by lift. The antenna structure above it is a further 184 feet (56 m) tall. the mast's foundations penetrate 20 feet (6 m) into the ground and the whole structure, including foundations, weighs 11,200 tonnes. The tower was designed by Arup. When built, it was the third-tallest freestanding structure in Europe, after the Ostankino Tower at 1,772 feet (540 m) and the Fernsehturm Berlin (current height 1,207 feet (368 m)). The top of the tower is 1,949 feet (594 m) above sea level due to the site's elevated position on the eastern edge of the Pennines. The tower is not open to the public. There is an observation area off the main road that runs past it. The tower has a top-floor interior equipment area at a height of 330 metres which is accessible to people.^[3]

The tower at night

In 2002, English Heritage granted the tower Grade II listed building status for its 'significant architectural or historic interest'.^[1]

Ownership

The tower is owned by Arqiva, previously the Independent Broadcasting Authority Engineering privatised as NTL Broadcast.

Broadcast details

Emley Moor tower broadcasts six digital television multiplexes, three digital radio ensembles and two independent local radio stations (Capital Yorkshire and Heart Yorkshire) over an area of approximately 10,000 km². It is the main station for 57 relays and repeaters throughout Yorkshire and the surrounding counties. In July 2007 it was confirmed by Ofcom that Emley Moor would remain a B group transmitter after DSO (digital switchover).

The area is important for RF, radio frequency transmission and from the foot of the structure both Holme Moss and the Moorside Edge Transmitter are visible. They are within a ten-mile (16 km) radius and are SW and WNW respectively.

The television coverage area covers one of the largest areas in the UK; covering most of Yorkshire including Hull, Leeds, Sheffield and York. Some transmissions can be received in Greater Manchester across the Pennines due to the height of the antenna on the tower and the strong signal.

Repairs and alterations

Over the years, the structure has been updated to reflect the changing nature of communications and technology. At the top and bottom of the tower supporting structures have been attached to accommodate dishes and aerials.

The BBC reported in July 2006 that for up to two weeks it would broadcast analogue and digital signals at a lower power than usual, or shut down between 0900 and 1500 BST on weekdays from late July until 4 August to allow aircraft warning lights to be fitted and repairs carried out. Repairs were estimated to affect around five million homes; however, a spokesperson for National Grid Wireless announced that the work had been scheduled around major events.^[4]

Digital UK reported in April 2010 that the transmitter would undergo work in preparation for the digital switchover in 2011. Disruption to some or all Freeview services was expected to last for around two months, during which time a reserve transmitter would continue to broadcast the five main analogue channels.^[5] The work was then reported to be continuing into September due to "poor weather conditions and complex engineering issues."

Channels listed by frequency

Emley Moor's distinctive tapering form on the moorland

Analogue radio (FM)

Digital radio (DAB)

Analogue television

Analogue television transmissions from Emley Moor have now ceased permanently. BBC Two analogue closed on 7 September 2011 and ITV1 temporarily moved onto its frequency at the time to allow BBC A to launch in its place. The remaining four analogue services closed on 21 September 2011, with the remaining digital multiplexes given a power increase.

Relays

Below is a list of transmitters that relay Emley Moor.

Digital television

Other structures of comparable height

• Emley Moor is 20 metres (66 ft) taller than The Shard, which is the second-tallest free-standing structure in the United Kingdom
• It is 95 metres (312 ft) taller than One Canada Square (Canary Wharf), Britain's second tallest building, which is 235 metres (771 ft) high.
• The Belmont mast in Lincolnshire, a guyed mast is, after it was shortened in April 2010, 351.5 metres (1,153 ft) high, making it the 2nd highest structure of any kind in the UK after Skelton.
• The very similar Sint-Pieters-Leeuw Tower in Belgium is around 300 metres tall.
• Torreta de Guardamar, a VLF-transmission mast of Spanish military near Guardamar is 370 metres tall
• Gerbrandy Tower in Lopik is 366.9 metres tall.
• The Eiffel Tower is 300 metres (984 ft) high, with an additional 24 metres (79 ft) antenna on top.
• The Riga radio and TV tower is the tallest freestanding structure in the EU, at 368.5 m (1209 ft)
• The Ostankino Tower, in Moscow, is the tallest freestanding structure in Europe, at 540 metres (1772 ft).

See also

• Telecommunications in the United Kingdom
• Radio masts and towers
• List of catastrophic collapses of radio masts and towers
• List of tallest buildings and structures in Great Britain
• List of towers
• List of masts
• List of radio stations in the United Kingdom
• List of tallest freestanding structures in the world
• The Shard

References

• Bartak, A.J.J. (February 1972). "The new tower for the Independent Television Authority at Emley Moor, Yorkshire". The Structural Engineer (Institution of Structural Engineers) 50 (2): 67–80. 

External links

Wikimedia Commons has media related to Emley Moor Tower.

• The Transmission Gallery: photographs, coverage maps and information
• Emley Moor TV Transmitter, including co-receivable transmitters
• Emley Moor Tower (1970) at Structurae.
• Diagrams - SkyscraperPage.com
• Google Maps
• Live Maps
• BBC Bradford and West Yorkshire - Emley Moor: Inside and Out!
• Emley Moor Transmitter at thebigtower.com
• Gallery of Emley Moor Mast: Views of an iconic Huddersfield landmark
• A Flickr page of pictures from the inside of the tower

Television transmitter and major relay sites in the United Kingdom England East Mendlesham Sandy Heath Sudbury Tacolneston East Midlands Belmont Chesterfield Waltham Greater London Alexandra Palace Croydon Crystal Palace North East Berwick-upon-Tweed Burnhope Chatton Pontop Pike North West Caldbeck Sandale Storeton West Kirby Winter Hill South East Bluebell Hill Chillerton Down Dover Frémont Point (Channel Islands) Hannington Heathfield Membury Midhurst Oxford Rowridge Whitehawk Hill South West Beacon Hill Caradon Hill Huntshaw Cross Mendip North Hessary Tor Redruth Stockland Hill Washford West Midlands Lichfield Ridge Hill Sutton Coldfield The Wrekin Yorkshire and the Humber Bilsdale Emley Moor Halifax Holme Moss Oliver's Mount Sheffield Scotland Angus Balgownie Black Hill Bonchester Bridge Bressay Craigkelly Darvel Durris Eitshal Eyemouth Galashiels Hawick Jedburgh Keelylang Hill Kirk o'Shotts Knock More Meldrum Mounteagle Rosemarkie Rumster Forest Selkirk Skriaig Tay Bridge Yetholm Wales Arfon Blaenplwyf Carmel Ferryside Flint Haverfordwest Kilvey Hill Llanddona Moel-y-Parc Preseli St Hilary Storeton Wenvoe Wrexham-Rhos Northern Ireland Black Mountain Brougher Mountain Divis Limavady Londonderry Strabane Italics denotes a transmitter no longer used for transmitting television signals.