Emley Moor transmitting station

Arqiva Emley Moor Tower
Emley Moor transmitting station (West Yorkshire)
Tower height 330.4 m (1,084 ft)
Coordinates 53°36′43″N 1°39′52″W / 53.611944°N 1.664444°W / 53.611944; -1.664444Coordinates: 53°36′43″N 1°39′52″W / 53.611944°N 1.664444°W / 53.611944; -1.664444
Grid reference SE222128
Built 1969 - 1971
BBC region BBC Yorkshire
ITV region ITV Yorkshire
Local TV service Made in Leeds

Emley Moor transmitting station[1] is a telecommunications and broadcasting facility on Emley Moor,[1] 1 mile (1.6 km) west of Emley, in Kirklees, West Yorkshire, England (national grid reference: SE2219712899). The most visible feature of the structure is its 1,084 feet (330.4 m) tall[1] concrete tower, which is a Grade II listed building. It is the tallest freestanding structure in the United Kingdom,[1][2] seventh tallest freestanding structure in the European Union,[1] fourth tallest tower in the European Union,[1] and 24th tallest tower in the world.[1]

The tower's current 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'.[1]

History

The present concrete 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. In 1964, it was replaced by a taller 385.5 metres (1,265 ft) guyed mast, identical to the structure at Belmont transmitting station in Lincolnshire, at 53°36′46″N 1°39′58″W / 53.612700°N 1.666078°W / 53.612700; -1.666078 (see map on http://tx.mb21.co.uk/gallery/gallerypage.php?txid=336&pageid=69 ). The dismantled lattice tower was rebuilt at Craigkelly transmitting station. Yorkshire Television commenced broadcasting from the Emley Moor transmitter following the reorganization of the ITV franchises on 29 July 1968 from YTV's new studios at Kirkstall Road in Leeds.

Collapse of second mast

Emley Moor has been a transmission site since the earliest days of television. The first permanent transmitter built there was for ITV, covering much of the north of England. It had a 135 metres (443 ft) lattice tower, which provided limited coverage. Its performance was improved in anticipation of colour PAL transmissions in 1966, when a 385 metres (1,263 ft) guy-supported tubular mast was erected. It was constructed from curved steel segments to form a 2.75 metres (9 ft) diameter tube, 275 metres (902 ft) long, and was surmounted by a lattice section 107 metres (351 ft) 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 man-made structures in the world. It was designed by British Insulated Callender's Cables (BICC), and manufactured by EMI, and built by J. L. Eve Construction.

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 caused the structure to collapse. 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 Independent Television Authority (ITA) owned a collapsible emergency mast, 61 metres (200 ft) 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 were hired, and a 204 metres (669 ft) 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 metres (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.

A section of the collapsed tower was converted for use as a racing control tower at Huddersfield Sailing Club.[3]

New mast

After the temporary masts, erection of the current concrete tower began in 1969. It was not built on the site where the mast had stood, but instead a bit southeast at 53°36′43″N 1°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 & 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, 275 metres (902 ft) tall, constructed of reinforced concrete, and is topped by a 55 metres (180 ft) steel lattice mast which carries the antennas.

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).[1] 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 (1,083 ft), which is accessible to people.[4]

The tower at night

In 2002, English Heritage granted the tower Grade II listed building status[1] for its 'significant architectural or historic interest'.[2]

Ownership

The tower is currently 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 digital switchover (DSO).

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.

Its television coverage area is one of the largest 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 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.

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.[5]

Digital UK reported in April 2010 that the transmitter would undergo work in preparation for the digital switchover (DSO) 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.[6] 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)

frequency kW[7] service
105.1 MHz 2.55 Capital Yorkshire
106.2 MHz 2.35 Heart Yorkshire

Digital radio (DAB)

frequency block kW[7] 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 Leeds

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 mux to launch in its place. The remaining four analogue services closed on 21 September 2011, with the remaining digital multiplexes given a power increase.

frequency UHF kW service
599.25 MHz 37 870 Channel 5
631.25 MHz 41 870 Channel 4
655.25 MHz 44 870 BBC One
679.25 MHz 47 870 ITV1
711.25 MHz 51 870 BBC Two

Relays

Below is a list of transmitters that relay Emley Moor.

Digital television

transmitter kW BBC-A BBC-B D3&4 SDN ARQ-A ARQ-B Pol. A.G.
Addingham 0.005 43 46 40 N/A N/A N/A V B E K
Armitage Bridge 0.002 49 54 58 N/A N/A N/A V C/D E
Batley 0.003 49 54 58 N/A N/A N/A V C/D E
Beecroft Hill 0.2 59 50- 55 N/A N/A N/A V C/D E
Blackburn in Rotherham 0.002 60 53 57 N/A N/A N/A V C/D E
Bradford West 0.003 55 50- 59 N/A N/A N/A V C/D E
Brockwell 0.002 45 39 42 N/A N/A N/A V B E K
Calver Peak 0.05 45 39 42 N/A N/A N/A V B E K
Chesterfield 0.4 [r 1] 26 29 23 43 46 40 V K
Cleckheaton 0.002 59 50- 55 N/A N/A N/A V C/D E
Conisbrough 0.002 60 53 57 N/A N/A N/A V C/D E
Cop Hill 0.2 25 28 22 N/A N/A N/A V A K
Copley 0.002 59 50- 55 N/A N/A N/A V C/D E
Cornholme 0.008 49 54 58 N/A N/A N/A V C/D E
Cowling 0.003 42 49 45 N/A N/A N/A V B E
Cragg Vale 0.005 49 54 58 N/A N/A N/A V C/D E
Cullingworth 0.003 50- 59 55 N/A N/A N/A V C/D E
Dronfield 0.002 50- 55 59 N/A N/A N/A V C/D E
Edale 0.002 60 53 57 N/A N/A N/A V C/D E
Elland 0.002 49 54 58 N/A N/A N/A V C/D E
Grassington 0.012 23 26 29 N/A N/A N/A V A K
Hagg Wood 0.007 59 50 55 N/A N/A N/A V C/D E
Halifax 0.1 24 27 21+ N/A N/A N/A V A K
Hasland 0.002 57 53 60 N/A N/A N/A V C/D E
Headingley 0.002 49 54 58 N/A N/A N/A V C/D E
Hebden Bridge 0.05 25 28 22 N/A N/A N/A V A K
Heyshaw 0.1 60 53 57 N/A N/A N/A V C/D E
Holmfield 0.004 59 50- 55 N/A N/A N/A V C/D E
Holmfirth 0.005 49 54 58 N/A N/A N/A V C/D E
Hope 0.002 28 25 22 N/A N/A N/A V A K
Idle 0.05 24 27 21+ 42 45 39 V K
Keighley 2 61 54 58 57 53 60 V C/D E
Keighley Town 0.002 23 29 26 N/A N/A N/A V A K
Kettlewell 0.026 42 39 45 N/A N/A N/A V B E K
Longwood Edge 0.008 59 50- 55 N/A N/A N/A H C/D E
Luddenden 0.012 60 53 57 N/A N/A N/A V C/D E
Lydgate 0.002 23 29 26 N/A N/A N/A V A K
Millhouse Green 0.002 49 54 58 N/A N/A N/A V C/D E
Oughtibridge 0.008 59 50- 55 N/A N/A N/A V C/D E
Oxenhope 0.04 25 28 22 N/A N/A N/A V A K
Primrose Hill 0.006 60 53 57 N/A N/A N/A V C/D E
Ripponden 0.012 49 54 58 N/A N/A N/A V C/D E
Shatton Edge 0.2 58 49 54 N/A N/A N/A V C/D E
Sheffield 1 27 21+ 24 42 45 39 V K
Skipton 2 49 42 45 N/A N/A N/A V B E
Skipton Town 0.003 24 21+ 27 N/A N/A N/A V A K
Stocksbridge 0.002 49 54 58 N/A N/A N/A V C/D E
Sutton-in-Craven 0.002 23 29 26 N/A N/A N/A V A K
Tideswell Moor 0.05 60 53 57 N/A N/A N/A V C/D E
Todmorden 0.1 39 42 45 N/A N/A N/A V B E K
Totley Rise 0.016 51 48 52 N/A N/A N/A V B C/D E
Walsden 0.01 60 53 57 N/A N/A N/A V C/D E
Walsden South 0.002 43 50 46 N/A N/A N/A V B E
Wharfedale 0.4 25 28 22 N/A N/A N/A V A K
Wheatley 0.3 49 54 58 N/A N/A N/A V C/D E
Wincobank 0.002 59 50- 55 N/A N/A N/A V C/D E
  1. ↑ Apart from BBC B which transmits at 800 W.

Other structures of comparable height

See also

References

  1. 1 2 3 4 5 6 7 8 9 10 "Emley Moor Mast". The Huddersfield Daily Examiner. Huddersfield: Trinity Mirror North West. Retrieved 3 April 2017.
  2. 1 2 "How TV transmitters transformed and towered over the UK". Ofcom.org.uk. Ofcom.
  3. ↑ Senior, Steve. "The fall and rise of Emley Moor - Emley Moor Mk2 lives!". mb21.co.uk. mb21 - UK Broadcast Transmission. Retrieved 3 April 2017.
  4. ↑ "Dewsbury mum-of-two wins trip up Emley Moor mast after being named unsung hero". The Huddersfield Daily Examiner. Huddersfield: Trinity Mirror North West. 19 July 2014. Retrieved 3 April 2017.
  5. ↑ "Transmitter work affects millions". BBC News. 25 July 2006. Retrieved 3 April 2017.
  6. ↑ "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. Retrieved 11 May 2010.
  7. 1 2 Radio Listeners Guide 2010
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