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Emley Moor transmitting station

Coordinates:53°36′43″N1°39′52″W/ 53.611944°N 1.664444°W/53.611944; -1.664444
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Arqiva Emley Moor Tower
Emley Moor transmitting station is located in West Yorkshire
Emley Moor transmitting station
Emley Moor transmitting station (West Yorkshire)
Tower height1,047 ft (319 m)
Coordinates53°36′43″N1°39′52″W/ 53.611944°N 1.664444°W/53.611944; -1.664444
Grid referenceSE222128
Built1969–1971
BBC regionBBC Yorkshire
ITV regionITV Yorkshire
Local TV serviceLocal TV Leeds
That's York

TheEmley Moor transmitting station[1]is atelecommunicationsandbroadcastingfacility on Emley Moor,[1]1 mile (1.6 km) west of the village centre ofEmley,[n 1]inHuddersfield,West Yorkshire,England.

It is made up of a 1,047 ft (319 m)[1]concretetower and apparatus that began to transmit in 1971. It is protected under UK law as a Grade IIlisted building.It is the tallest freestanding structure in theUnited Kingdom,[1][2]and25th tallest tower in the world.[1]It was the seventh tallest freestanding structure and was fourth tallest tower in the European Union beforeBrexit.[1]When built it was the sixth tallest freestanding structure in the world after theOstankino Tower,theEmpire State Building,875 North Michigan Avenue(known as The John Hancock Center), theBerliner FernsehturmandTokyo Tower.[3]

The tower's current official name,The Arqiva Tower,is shown on a sign beside the offices at the base of the tower, but it is commonly known just as"Emley Moor Mast".[1]

In 2021, the antenna was replaced, to accommodate frequency changes for mobile phone use, by a shorter antenna of 36 ft (11 m) but the structure still remains the tallest freestanding structure in the United Kingdom.

History[edit]

Emley Moor has been a transmission site since the earliest days of commercial television in the UK. The present concrete tower is the third antenna support structure to have occupied the site.

The first permanent transmitter built there was forITV,covering much of the north of England. It had a 443 feet (135 m) lattice tower, which provided limited coverage. This original 443-foot (135 m)lattice towerwas erected in 1956 to provideIndependent Televisionbroadcasts to the Yorkshire area. It entered service on 3 November 1956, transmittingGranada Televisionprogrammes on weekdays, andABC TVprogrammes at weekends.

Second mast and collapse[edit]

In 1964, in anticipation of colourPALtransmissions set to begin in 1966, the original 443-foot (135 m) lattice tower was replaced by a taller 1,265-foot (385.5 m)guyed mast,identical to the structure atBelmont transmitting stationin Lincolnshire. The dismantled lattice tower was rebuilt atCraigkelly transmitting station.[4]Yorkshire Televisioncommenced broadcasting from the Emley Moor transmitter following the reorganisation of the ITV franchises on 29 July 1968.

The guy-supportedtubular mastwas constructed from curved steel segments to form a 9 feet (2.75 m) diameter tube, 902 feet (275 m) long, and was surmounted by a lattice section 351 feet (107 m) tall, and a capping cylinder, bringing the total height to 1,265 feet (385.5 m). At the time of its construction, it was one of the tallest human-made structures in the world. It was designed byBritish Insulated Callender's Cables(BICC), and manufactured byEMI,and built byJ. L. Eve Construction.

Its ropes weighed 85 long tons (86 t), made byBritish Ropes,with steel fromSteel, Peech and TozerofTempleboroughin South Yorkshire. The column weighed 210 long tons (210 t) and had 375 segments, with steel fromUnited Steel CompaniesatScunthorpein northernLincolnshire.[5]

The cylindrical steel mast was regularly coated in ice during the winter, and largeiciclesformed on the guy wires, placing them under great strain. During winter, ice often fell from the guy-wires. For this reason, amber 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.[6]

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 caused the structure to collapse. The duty engineer wrote the following in the station's log book, demonstrating that failure of the structure was completely unexpected:

  • Day [shift]: Lee, Caffell, Vander Byl [surnames]
  • 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 [shift]: Glendenning, Bottom, Redgrove[a][surnames]
  • 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 the roof of a local church[7]and across the transmitter site buildings, no one was injured. It completely disabled theBBC2UHF transmitter and the ITV VHF transmitter, leaving several million people without service.BBC1VHF television transmissions continued fromHolme Moss.TheIndependent Television Authority(ITA) owned a collapsible emergency mast, 200 feet (61 m) tall, which was moved to Emley from theLichfield transmitting stationso that some service could be restored.ITVsignals were restored to 2.5 million viewers within four days. TheBBCprovided a mobile mast on anoutside broadcastvan 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 were hired, and a 669 feet (204 m) mast was erected in under 28 days at a cost of£100,000(equivalent to £2.1 million in 2023). This mast could hold only one set of antennae, 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 299 feet (91 m) mast, improving coverage.

Vortex sheddingbehind a circular cylinder. In this animation, the flows on the two sides of the cylinder are shown in different colours, to show that the vortices from the two sides alternate, which can build an oscillating motion in the cylinder. Courtesy, Cesareo de La Rosa Siqueira.

The accumulation of ice was believed to have caused the collapse, but a committee of inquiry attributed it tovortex sheddingwhich occurred over a five year period of low but steady wind speed, enhanced during periods of high wind speed.[6]Dampingmodifications, including hanging 150 long tons (150 t) of steel chains within each structure, were made to similar masts at Belmont andWinter Hill.None of the modified masts have collapsed.

A section of the collapsed tower was converted for use as a racing control tower at Huddersfield Sailing Club.[8]

New tower[edit]

After the setting up of temporary masts, erection of the currentconcretetower began in 1969. It was not built on the site where the original mast had stood, but slightly to the south-east at53°36′43″N1°39′52″W/ 53.612056°N 1.664390°W/53.612056; -1.664390.UHF (625-line colour) transmissions commenced on 21 January 1971, and the older VHF (405-line black and 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 tapered cylindrical pillar, 902 feet (275 m) tall, constructed ofreinforced concrete,and is topped by a 180 feet (55 m) steel lattice mast which carries the antennae.

Structure[edit]

The structure is a tapered, reinforced concretetower.It is the tallest freestanding structure in the United Kingdom at a height of 1,084 feet (330 m),[1]66 feet (20 m) taller thanThe Shard.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 11,000 long tons (11,200 t). The tower was designed byArup.When built, it was the third-tallest freestanding structure in Europe, after theOstankino Towerat 1,772 feet (540 m), and theFernsehturm Berlin(current height 1,207 feet (368 m)). The top of the tower is 1,949 feet (594 m) abovesea level,due to the site's elevated position on the eastern edge of the Pennines. The tower is not open to the public. There was an observation area off the main road that runs past it, but as of 25 February 2018, this seems to be closed.[9]The tower has a top-floor interior equipment area at a height of 1,083 feet (330 m), which is accessible to people.[10]

The tower at night

In 2002,English Heritagegranted the tower Grade IIlisted buildingprotection under UK law, being the lowest and most common of three categories, for meeting its criteria of significant architectural or historic interest.[2][1]

Ownership[edit]

The tower is currently owned byArqiva,previously theIndependent Broadcasting AuthorityEngineering section, privatised asNTL Broadcast.

Broadcast details[edit]

Emley Moor tower broadcasts sixdigital televisionmultiplexes, threedigital radioensembles, and two independent local radio stations (Capital YorkshireandHeart Yorkshire), over an area of approximately 3,900 square miles (10,000 km2). It is the main station for 57 relays and repeaters throughoutYorkshireand the surrounding counties. In July 2007, it was confirmed byOfcomthat Emley Moor would remain a B group transmitter afterdigital switchover(DSO).

The area is important for RF,radio frequencytransmission, and from the foot of the structure, bothHolme Mossand theMoorside Edge transmitterare visible. They are within a ten-mile (16 km) radius, and are located to the southwest and west-northwest, respectively.

Its television coverage area is one of the largest in the UK; covering most ofYorkshireand parts of theEast MidlandsincludingLeeds,Sheffield,York,Chesterfield,WorksopandMansfield.Some transmissions can be received inGreater Manchesteracross thePenninesdue to the height of the antenna on the tower and the powerful signal.

Repairs and alterations[edit]

Over the years, the concrete 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.

TheBBCreported 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 09:00 and 15:00 BST on weekdays from late July until 4 August, to allowaircraft warning lightsto be fitted and repairs carried out. Repairs were estimated to affect around five million homes; however, a spokesperson forNational Grid Wirelessannounced that the work had been scheduled around major events.[11]

Digital UKreported in April 2010 that the transmitter would undergo work in preparation for the digital switchover (DSO) in 2011. Disruption to some or allFreeviewservices was expected to last for around two months, during which time a reserve transmitter would continue to broadcast the five main analogue channels.[12]The work was then reported to be continuing into September due to "poor weather conditions and complex engineering issues".

In March 2018, a temporary 1,063 ft (324 m) mast was erected so that work could be undertaken on the main tower's transmitting arrays without interrupting transmissions,.[13]The temporary mast was due to be removed by the end of 2021. However, it was not until summer 2023 that work got underway to dismantle it, carried out by Turmbau Steffens & Nölle GmbH of Berlin.[14]

Channels listed by frequency[edit]

Emley Moor's distinctive tapering form on the moorland

Analogue radio (FM)[edit]

frequency kW[15] service
105.1MHz 2.55 Capital Yorkshire
106.2 MHz 2.35 Heart Yorkshire

Digital radio (DAB)[edit]

frequency block kW[15] operator
216.928 MHz 11A 10 Sound Digital
222.064 MHz 11D 8.5 Digital One
225.648 MHz 12B 10 BBC National DAB
229.072 MHz 12D 5 BBC Radio Leeds

Analogue television[edit]

At Emley Moor, BBC Two analogue closed on 7 September 2011, and ITV Yorkshire temporarily moved onto its frequency at the time to allow the BBC A MUX to launch in its place. The remaining four analogue services closed on 21 September 2011, when the remaining digital multiplexes were allowed to transmit with increased power.

frequency UHF kW service
599.25MHz 37 870 Channel 5
631.25MHz 41 870 Channel 4
655.25MHz 44 870 BBC1 Yorkshire
679.25MHz 47 870 Yorkshire
711.25MHz 51 870 BBC2 Yorkshire

Relays[edit]

Below is a list of transmitters that relay Emley Moor.

Digital television[edit]

transmitter kW BBC-A BBC-B D3&4 SDN ARQ-A ARQ-B Local Pol. A.G.
Addingham 0.005 43 46 40 — — — — V B K
Armitage Bridge 0.002 32 35 34 — — — — V A K
Batley 0.003 32 35 34 — — — — V A K
Beecroft Hill 0.2 37 45 42 — — — 39 V B K
Blackburn in Rotherham 0.002 40 46 43 — — — — V B K
Bradford West 0.003 39 45 42 — — — — V B K
Brockwell 0.002 45 39 42 — — — — V B K
Calver Peak 0.05 45 39 42 — — — — V B K
Chesterfield 0.4[r 1] 31 29 37 43 46 40 — V K
Cleckheaton 0.002 29 37 31 — — — — V A K
Conisbrough 0.002 40 46 43 — — — — V B K
Cop Hill 0.2 25 28 22 — — — — V A K
Copley 0.002 29 37 31 — — — — V A K
Cornholme 0.008 32 35 34 — — — — V A K
Cowling 0.003 42 49 45 — — — — V B K
Cragg Vale 0.005 32 35 34 — — — — V A K
Cullingworth 0.003 39 45 42 — — — — V B K
Dronfield 0.002 39 45 42 — — — — V B K
Edale 0.002 40 46 43 — — — — V B K
Elland 0.002 32 35 34 — — — — V B K
Grassington 0.012 23 26 30 — — — — V A K
Hagg Wood 0.007 39 45 42 — — — — V B K
Halifax 0.1 24 27 21+ — — — — V A K
Hasland 0.002 32 35 34 — — — — V A K
Headingley 0.002 32 35 34 — — — — V A K
Hebden Bridge 0.05 25 28 22 — — — — V A K
Heyshaw 0.1 39 45 42 — — — — V B K
Holmfield 0.004 29 37 31 — — — — V A K
Holmfirth 0.005 32 35 34 — — — — V A K
Hope 0.002 28 25 22 — — — — V A K
Idle 0.05 23 30 26 32 35 34 — V A K
Keighley 2 40 46 43 29 31 37 — V K
Keighley Town 0.002 23 29 26 — — — — V A K
Kettlewell 0.026 42 39 45 — — — — V B K
Longwood Edge 0.008 29 37 31 — — — — H A K
Luddenden 0.012 40 46 43 — — — — V B K
Lydgate 0.002 21 27 24 — — — — V A K
Millhouse Green 0.002 32 35 34 — — — — V A K
Oughtibridge 0.008 23 30 26 — — — — V A K
Oxenhope 0.04 25 28 22 — — — — V A K
Primrose Hill 0.006 40 46 43 — — — — V B K
Ripponden 0.012 32 35 34 — — — — V A K
Shatton Edge 0.2 32 35 34 — — — — V A K
Sheffield 1[r 2] 27 21+ 24 42 45 39 35 V K
Skipton 2 49 42 45 — — — — V B E
Skipton Town 0.003 24 21+ 27 — — — — V A K
Stocksbridge 0.002 40 46 43 — — — — V B K
Sutton-in-Craven 0.002 23 30 26 — — — — V A K
Tideswell Moor 0.05 40 46 43 — — — — V B K
Todmorden 0.1 39 42 45 — — — — V B K
Totley Rise 0.016 33 48 36 — — — — V A K
Walsden 0.01 40 46 43 — — — — V B K
Walsden South 0.002 32 35 34 — — — — V A K
Wharfedale 0.4 25 28 22 — — — — V A K
Wheatley 0.3 32 35 34 — — — — V A K
Wincobank 0.002 29 37 31 — — — — V A K
  1. ^Apart from BBC A, BBC B and Digital 3&4 which transmits at 800 W.
  2. ^Apart from Local Multiplex which transmits at 400 W.

Other structures of comparable height[edit]

Taller structures
Smaller structures

See also[edit]

Notes[edit]

  1. ^Then-27-year-old engineer Alan Redgrove, who 51 years later appeared in a 2020 episode of theDiscovery Channel UKseriesMassive Engineering Mistakes,sharing his recollections of the collapse.[6]

References[edit]

References
  1. ^abcdefghi"Emley Moor Mast".Huddersfield Daily Examiner.Huddersfield:Reach plc.Retrieved3 April2017.
  2. ^ab"How TV transmitters transformed and towered over the UK".Ofcom.org.uk.Ofcom.Archived fromthe originalon 1 August 2011.
  3. ^"Diagrams".Skyscraperpage.Retrieved10 July2021.
  4. ^"TheBigTower Craigkelly Transmitter".Thebigtower.Retrieved2 August2020.
  5. ^The Times,Friday 10 September 1965, p. 9
  6. ^abc"Episode #2.7".Massive Engineering Mistakes.Season 2. Episode 7.BriteSpark Films.10 October 2020. 26:55 minutes in.Discovery Channel UK.
  7. ^"Photographic image"(JPG).Tx.mb21.co.uk.Retrieved6 September2023.
  8. ^Senior, Steve."The fall and rise of Emley Moor - Emley Moor Mk2 lives!".Tx.mb21.co.uk.Retrieved3 April2017.
  9. ^"Emley Moor transmitting station".TripAdvisor.Retrieved18 September2018.
  10. ^"Dewsbury mum-of-two wins trip up Emley Moor mast after being named unsung hero".Huddersfield Daily Examiner.Huddersfield:Reach plc.19 July 2014.Retrieved3 April2017.
  11. ^"Transmitter work affects millions".BBC News.25 July 2006.Retrieved3 April2017.
  12. ^"I receive my TV signal from the Emley Moor transmitter - why are my TV services experiencing interruptions?".help.DigitalUK.co.uk.Digital UK.29 April 2010.Retrieved11 May2010.[dead link]
  13. ^Himelfield, Dave (12 April 2019)."Where work on Emley Moor Mast and the second temporary mast is up to".Huddersfield Daily Examiner.Huddersfield:Reach plc.Retrieved19 April2019.
  14. ^"GoggleboxTech.UK".Goggleboxtech.uk.Retrieved6 September2023.
  15. ^abRadio Listeners Guide 2010
  • Bartak, A. J. J. (February 1972). "The new tower for the Independent Television Authority at Emley Moor, Yorkshire".The Structural Engineer.50(2).Institution of Structural Engineers:67–80.
Notes
  1. ^It lies in OS grid square SE221899

External links[edit]

Wikimedia Commons has media related toEmley Moor Tower.
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