Emley Moor transmitting station#Collapse of second mast

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 for ITV, covering much of the north of England. It had a {{convert|135|m|ft|0|order=flip}} lattice tower, which provided limited coverage. This original {{convert|135|m|ft|0|adj=on|order=flip}} lattice tower was erected in 1956 to provide Independent Television broadcasts to the Yorkshire area. It entered service on 3 November 1956, transmitting Granada Television programmes on weekdays, and ABC TV programmes at weekends.

In 1964, in anticipation of colour PAL transmissions set to begin in 1966, the original {{convert|443|ft|adj=on}} lattice tower was replaced by a taller {{convert|385.5|m|ft|0|adj=on|order=flip}} guyed mast, identical to the structure at Belmont transmitting station in Lincolnshire. The dismantled lattice tower was rebuilt at Craigkelly transmitting station.{{cite web |title=TheBigTower Craigkelly Transmitter |url=https://www.thebigtower.com/live/Craigkelly/Index.htm |access-date=2 August 2020 |website=Thebigtower.com}} Yorkshire Television commenced broadcasting from the Emley Moor transmitter following the reorganisation of the ITV franchises on 29 July 1968.

The guy-supported tubular mast was constructed from curved steel segments to form a {{convert|2.75|m|ft|0|order=flip}} diameter tube, {{convert|275|m|ft|0|order=flip}} long, and was surmounted by a lattice section {{convert|107|m|ft|0|order=flip}} tall, and a capping cylinder, bringing the total height to {{convert|385.5|m|ft|0|order=flip}}. At the time of its construction, it was one of the tallest human-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.

Its ropes weighed {{convert|85|lt|t|abbr=}}, made by British Ropes, with steel from Steel, Peech and Tozer of Templeborough in South Yorkshire. The column weighed {{convert|210|lt|t}} and had 375 segments, with steel from United Steel Companies at Scunthorpe in northern Lincolnshire.The Times, Friday 10 September 1965, p. 9

The cylindrical steel mast was regularly coated in ice during the winter, and large icicles formed 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.

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{{efn|Then-27-year-old engineer Alan Redgrove, who 51 years later appeared in a 2020 episode of the Discovery Channel UK series Massive Engineering Mistakes, sharing his recollections of the collapse.{{cite episode |title=Episode #2.7 |series=Massive Engineering Mistakes |publisher=BriteSpark Films |network=Discovery Channel UK |season=2 |number=7 |date=10 October 2020 |minutes=26:55}}}} [surnames]
• {{convert|1265|ft|m|abbr=on}} 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.

File:Emley Moor Mast Wreckage.jpg

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{{cite web|url=https://tx.mb21.co.uk/emley/eyewitness/emley_moor-kh-a15.jpg|format=JPG|title=Photographic image|website=Tx.mb21.co.uk|access-date=6 September 2023}} 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, {{convert|61|m|ft|0|order=flip}} 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 {{convert|204|m|ft|0|order=flip}} mast was erected in under 28 days at a cost of {{£|100000|link=yes}} (equivalent to £{{Inflation|UK|0.1|1969|r=1}} million in {{Inflation/year|UK}}). 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 {{convert|91|m|ft|0|order=flip}} mast, improving coverage.

Image:Vortex-street-animation.gif behind 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 to vortex shedding which occurred over a five year period of low but steady wind speed, enhanced during periods of high wind speed. Damping modifications, including hanging {{convert|150|lt|t}} 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.{{cite web|url=http://tx.mb21.co.uk/emley/hsc/|title=The fall and rise of Emley Moor – Emley Moor Mk2 lives!|last=Senior|first=Steve|website=Tx.mb21.co.uk|access-date=3 April 2017}}

After the setting up of temporary masts, erection of the current concrete tower began in 1969. It was not built on the site where the original mast had stood, but slightly to the south-east at {{coord|53.612056|N|1.664390|W|type:landmark}}. 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, {{convert|275|m|ft|0|order=flip}} tall, constructed of reinforced concrete, and is topped by a {{convert|55|m|ft|0|order=flip}} steel lattice mast which carries the antennae.

The structure is a tapered, reinforced concrete tower. It is the tallest freestanding structure in the United Kingdom at a height of {{convert|1084|ft|m|0}}, {{convert|20|m|ft|order=flip}} taller than The Shard. Reaching the tower room at the top of the concrete structure at {{convert|900|ft|m|0}} involves a seven-minute journey by lift. The antenna structure above it is a further {{convert|184|ft|m|0}} tall. The mast's foundations penetrate {{convert|20|ft|m|0}} into the ground, and the whole structure, including foundations, weighs {{convert|11200|t|lt|order=flip}}. The tower was designed by Arup. When built, it was the third-tallest freestanding structure in Europe, after the Ostankino Tower at {{convert|1772|ft|m|0}}, and the Fernsehturm Berlin (current height {{convert|1207|ft|m|0}}). The top of the tower is {{convert|1949|ft|m|0}} 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 was an observation area off the main road that runs past it, but as of 25 February 2018, this seems to be closed.{{cite web |title=Emley Moor transmitting station |url=https://www.tripadvisor.co.uk/Attraction_Review-g190748-d1064630-Reviews-Emley_Moor_transmitting_station-Huddersfield_West_Yorkshire_England.html |website=TripAdvisor |access-date=18 September 2018}} The tower has a top-floor interior equipment area at a height of {{convert|330|m|ft|0|order=flip}}, which is accessible to people.{{cite news|work=Huddersfield Daily Examiner|title=Dewsbury mum-of-two wins trip up Emley Moor mast after being named unsung hero|url=http://www.examiner.co.uk/news/west-yorkshire-news/dewsbury-mum-of-two-wins-trip-up-7456638|publisher=Reach plc|location=Huddersfield|date=19 July 2014|access-date=3 April 2017}}

File:Emley Moor Mast.png

In 2002, English Heritage granted the tower Grade II listed building protection under UK law, being the lowest and most common of three categories, for meeting its criteria of significant architectural or historic interest.

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

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 {{convert|10000|sqkm|sqmi|order=flip}}. 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 located to the southwest and west-northwest, respectively.

Its television coverage area is one of the largest in the UK; covering most of Yorkshire and parts of the East Midlands including Leeds, Sheffield, York, Chesterfield, Worksop and Mansfield. Some transmissions can be received in Greater Manchester across the Pennines due to the height of the antenna on the tower and the powerful signal.

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 09:00 and 15:00 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.{{cite news|url=http://news.bbc.co.uk/1/hi/england/west_yorkshire/5214240.stm|work=BBC News|title=Transmitter work affects millions|date=25 July 2006|access-date=3 April 2017}}

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.{{cite web|url=http://help.digitaluk.co.uk/display/4/kb/article.aspx?aid=7463|website=help.DigitalUK.co.uk|publisher=Digital UK|title=I receive my TV signal from the Emley Moor transmitter – why are my TV services experiencing interruptions?|date=29 April 2010|access-date=11 May 2010}}{{dead link|date=April 2017}} The work was then reported to be continuing into September due to "poor weather conditions and complex engineering issues".

In March 2018, a temporary {{cvt|324|m|ft|order=flip}} mast was erected so that work could be undertaken on the main tower's transmitting arrays without interrupting transmissions,.{{cite news | url=https://www.examinerlive.co.uk/news/west-yorkshire-news/work-emley-moor-mast-second-15445599 | title=Where work on Emley Moor Mast and the second temporary mast is up to

| newspaper=Huddersfield Daily Examiner | date=12 April 2019 | first=Dave |last=Himelfield | publisher=Reach plc | location=Huddersfield | access-date=19 April 2019}} 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.{{cite web|url=https://goggleboxtech.uk/gallery.php?id=2|title=GoggleboxTech.UK|website=Goggleboxtech.uk|access-date=6 September 2023}}

File:Emley Moor mast at sunset - geograph.org.uk - 497294.jpg

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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.

Below is a list of transmitters that relay Emley Moor.

{{Reflist|group=r}}

;Taller structures

• It is shorter than Skelton transmitting station in Cumbria, a guyed mast, which at {{convert|365|m|ft|0|order=flip}} is the highest structure (of any kind) in the UK.
• Skelton is comparable to the:
• Gerbrandy Tower, partially guyed, between IJsselstein and Lopik in the Netherlands at {{convert|366.9|m|ft|0|order=flip}};
• Torreta de Guardamar, guyed, in Spain at {{convert|370|m|ft|0|order=flip}}.
• The Ostankino Tower, in Moscow, is the tallest freestanding structure in Europe, at {{convert|540|m|ft|0|order=flip}}.
• The Kyiv TV Tower is the next-tallest freestanding structure in Europe at {{convert|385|m|ft|order=flip}}.
• The Riga radio and TV tower follows at {{convert|368.5|m|ft|0|order=flip}}.

;Smaller structures

• It is {{convert|20|m|ft|0|order=flip}} taller than The Shard in London, which is the next-tallest free-standing structure in the United Kingdom;
• It is {{convert|41|m|ft|0|order=flip}} taller than 22 Bishopsgate in London, Britain's second tallest building;
• It is {{convert|95|m|ft|0|order=flip}} taller than One Canada Square by Canary Wharf, London, Britain's third tallest building;
• Sint-Pieters-Leeuw Tower in Belgium is {{convert|302|m|ft|0|order=flip}};
• The Eiffel Tower in Paris, France is {{convert|300|m|ft|0|order=flip}}, plus a {{convert|24|m|ft|0|adj=on|order=flip}} antenna.

{{Portal|Radio|Television|Architecture|Yorkshire}}

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

{{notelist}}

;References

{{reflist}}

• {{cite journal|last=Bartak|first=A. J. J.|date=February 1972|title=The new tower for the Independent Television Authority at Emley Moor, Yorkshire|journal=The Structural Engineer|volume=50|issue=2|pages=67–80|publisher=Institution of Structural Engineers}}

;Notes

{{reflist|group=n}}

{{commons category|Emley Moor Tower}}

• [http://tx.mb21.co.uk/gallery/gallerypage.php?txid=336 The Transmission Gallery: photographs, coverage maps and information]
• [https://www.aerialsandtv.com/knowledge/transmitters/emley-moor-transmitter Info and pictures of Emley Moor transmitter including historical power/frequency changes and present co-receivable transmitters]
• {{Structurae|id=20013860|title=Emley Moor Tower (1970)}}.
• [http://skyscraperpage.com/diagrams/?b5736 Diagrams – SkyscraperPage.com]
• [https://www.bbc.co.uk/bradford/content/image_galleries/emley_moor_gallery.shtml BBC Bradford and West Yorkshire – Emley Moor: Inside and Out!]
• [http://www.TheBigTower.com/live/EmleyMoor/Index.htm Emley Moor transmitter at TheBigTower.com]
• [https://www.flickr.com/photos/horrgakx/sets/72157602397538539 A Flickr page of pictures from the inside of the tower]

{{Television transmitters in the UK}}

{{Emley Moor VHF 405-line Transmitter Group}}

{{Supertall}}

Category:Buildings and structures completed in 1971

Category:Buildings and structures in Kirklees

Category:Grade II listed buildings in West Yorkshire

Category:Mass media in Yorkshire

Category:Transmitter sites in England

Category:Towers in West Yorkshire

Category:1964 establishments in England

Category:1969 disestablishments

Category:1971 establishments in England

Category:Yorkshire Television

Category:Denby Dale