View source for Crystal Palace transmitting station

{{short description|Telecommunications site in Bromley, England}}
{{EngvarB|date=September 2017}}
{{Use dmy dates|date=September 2017}}
{{Infobox UK transmitter
|name = Arqiva Crystal Palace
|image = [[File:Cp mast.jpg|250px]]
|map_name = Greater London
|coordinates = {{coord|51.4242|-0.0750|type:landmark_region:GB|display=inline,title}}
|height2 = {{convert|219|m|ft|0}}<ref name="bromley-council">{{cite web |title=NGW planning application |url=http://212.85.26.243/WAM/pas/externalCasefile.do?councilName=London%20Borough%20of%20Bromley&appNumber=08/01463/FULL1 |url-status=dead |publisher=[[Bromley London Borough Council]] |date=23 April 2008 |access-date=13 September 2008 |archive-url=https://web.archive.org/web/20090519010239/http://212.85.26.243/WAM/pas/externalCasefile.do?councilName=London%20Borough%20of%20Bromley&appNumber=08%2F01463%2FFULL1 |archive-date=19 May 2009}}</ref>
|built = 28 March 1956
|demolished =
|collapsed =
|BBC = [[BBC London]]
|ITV = [[ITV London]]
|localtv = [[London Live (TV channel)|London Live]]
}}

The '''Crystal Palace transmitting station''', officially known as '''Arqiva Crystal Palace''', is a broadcasting and telecommunications site in the [[Crystal Palace, London|Crystal Palace]] area of the [[London Borough of Bromley]], England ({{gbmapping|TQ339712}}).<ref>[http://www.bbc.co.uk/rd/milestones/1990s.shtml BBC] Milestones. Retrieved 13 October 2008</ref> It is located on the site of the former television station and transmitter operated by [[John Logie Baird]] from 1933.<ref>Ray Herbert, ''The Crystal Palace Television Studios: John Logie Baird and British Television'', accessed online 6 January 2019 [http://www.bairdtelevision.com/crystalpalace.html Link]</ref>

The station is the [[list of tallest buildings and structures in London|eighth-tallest structure in London]], and is best known as the main television transmitter for the [[Greater London]] area and parts of the surrounding [[Home Counties]]. As such, it is the most important transmitter in the UK in terms of population covered. The transmitter is owned and operated by [[Arqiva]]. Given the transmitter's location on top of a {{convert|109|m|ft|adj=on}} hill, it is the highest structure above sea level in London.

==History and development==
[[File:Crystal Palace Transmitting Station at Night.jpg|thumb|At night]]
[[File:Crystal Palace Transmitter Mast.jpg|alt=Crystal Palace transmitter mast as seen from Old Cople Lane adjacent to the remains of the aquarium.|thumb|Crystal Palace transmitter mast as seen from Old Cople Lane adjacent to the remains of the aquarium.]]
The station was constructed in the mid-1950s among the ruins of [[the Crystal Palace]]. The Aquarium on whose site it stands was destroyed in 1941 during the demolition of the Palace's north water tower.<ref name="time-north-tower">{{cite magazine |title=War's Worst Raid |magazine=[[Time (magazine)|Time]] |url=http://www.time.com/time/magazine/article/0,9171,765495,00.html |url-status=dead |date=28 April 1941 |access-date=29 May 2008 |archive-url=https://web.archive.org/web/20081201013843/http://www.time.com/time/magazine/article/0,9171,765495,00.html |archive-date=1 December 2008}}</ref><ref name="pescod-north-tower">{{cite journal |last=Pescod |first=David, FLS |title=Correspondence |url=http://www.linnean.org/fileadmin/images/Linnean/Linnean_Archive/Linnean_21-2_April_2005.pdf |url-status=dead |journal=The Linnean |volume=21 |issue=2 |page=15 |publisher=[[Linnean Society of London]] |location=London |date=10 February 2005 |access-date=1 August 2012 |archive-url=https://web.archive.org/web/20111019103007/http://www.linnean.org/fileadmin/images/Linnean/Linnean_Archive/Linnean_21-2_April_2005.pdf |archive-date=19 October 2011 |df=dmy-all}}</ref> ([[John Logie Baird]]'s earlier transmitter and TV studios were a separate development at the other end of the Palace and perished with it in 1936.)<ref name="transdiffusion-baird">{{cite web |last=Elen |first=Richard G |title=Baird's independent television |url=http://www.transdiffusion.org/2003/04/05/baird_itv |publisher=Transdiffusion Broadcasting System |date=5 April 2003 |access-date=5 April 2015}}</ref><ref name="soundscapes-baird">{{cite journal |last=Herbert |first=Ray |title=Crystal Palace Television Studios |url=http://www.icce.rug.nl/~soundscapes/VOLUME01/Crystal_Palace.shtml |journal=Soundscapes |volume=1 |issue=4 |publisher=[[University of Groningen]] |location=Groningen, Netherlands |date=July 1998 |access-date=29 May 2008 |issn=1567-7745 |archive-date=14 February 2008 |archive-url=https://web.archive.org/web/20080214115151/http://www.icce.rug.nl/~soundscapes/VOLUME01/Crystal_Palace.shtml |url-status=dead }}</ref> Its new {{convert|219|m|ft|0|adj=on}}<ref name="bromley-council" /> tower was the tallest structure in London until the [[topping-out]] of [[One Canada Square]] at [[Canary Wharf]] in 1990.
[[File:Arqiva transmitting station Crystal Palace.jpg|alt=Arqiva transmitting station Crystal Palace|thumb|Arqiva transmitting station Crystal Palace]]
The first transmission from Crystal Palace took place on 28 March 1956, when it succeeded [[Alexandra Palace television station|the transmitter at Alexandra Palace]] where the BBC had started the world's first scheduled television service in November 1936. In November 1956 the first colour test transmissions began from Crystal Palace, relaying live pictures from the studios at Alexandra Palace after BBC TV had closed down for the night. In May 1958 the first experimental Band V 625-line transmissions started from Crystal Palace.

This tower was designed and built for BBC by British Insulated Callender's Construction Co. Ltd., with steelwork fabrication by [[Painter Brothers]] Ltd. of Hereford. The tower was required to transmit television programmes with good reception in 1957, and has a total height of {{convert|708|ft|m}}. The base of the tower is {{convert|120|ft|m}} to a side, and it rises in twelve diminishing panels to a {{convert|14.5|ft|m}} square platform at a height of {{convert|429|ft|m}}.<ref name="bbc-monograph-23">{{cite journal |last1=Wharton |first1=W. |last2=Platts |first2=G.C. |title=The Crystal Palace band I television transmitting aerial |url=http://downloads.bbc.co.uk/rd/pubs/archive/pdffiles/monographs/bbc_monograph_23.pdf |journal=BBC Engineering Division Monograph |publisher=BBC |date=February 1959 |page=5 |access-date=12 October 2013}}</ref> The tower was constructed using two masts as [[derrick]]s, one {{convert|230|ft|m}} and the other {{convert|125|ft|m}} high, in conjunction with a [[winch]]. At the time, a [[16mm film]] of the construction by BICC was produced; "''The Phoenix Tower - The Story of the Crystal Palace Television Tower''"<ref>{{Cite AV media |url=https://www.youtube.com/watch?v=HjBX7FTS36Y |title=The Phoenix Tower |date=2024-01-12 |last= |access-date=2025-04-15 |via=YouTube}}</ref> was available on loan from the BICC Film Library and has been released on the DVD "''The Pleasure Garden"'' from the [[British Film Institute|BFI]].<ref>{{cite journal |title=The BBC's Crystal Palace Television Tower |journal=Construction Bulletin |date=December 1957 |issue=11 |publisher=British Insulated Callender's Construction Company Ltd}}</ref><ref>{{cite journal |journal=Engineering |date=21 February 1958 |page=246}}</ref>

===Innovations===
The transmitter was the first in the UK to broadcast (experimentally) on [[576i|625 lines]] ([[Ultra high frequency|UHF]]) in 1962–1964, which it did on Channel 44, using a modified version of the [[Society of Motion Picture and Television Engineers|SMPTE]] optical [[monochrome]] [[test card]]<ref>{{cite web |url = http://www.radios-tv.co.uk/Pembers/Test-Cards/Test-Card-Technical.html#SMPTE |title = Not just a pretty face... |archive-url=https://web.archive.org/web/20190506044324/http://www.radios-tv.co.uk/Pembers/Test-Cards/Test-Card-Technical.html#SMPTE |archive-date=6 May 2019 |url-status=dead}}</ref> (not to be confused with the [[SMPTE color bars|SMPTE colour bars]]).

On 18 July 1986, with the [[The Proms|First Night of the Proms]] on BBC2, the transmitter became the first in the world to transmit stereophonic sound using the [[NICAM]] digital sound system.

===Television===
When built it transmitted BBC Television on the [[Very high frequency|VHF]] [[405-line television system|405-line]] system; the [[Croydon transmitting station|Croydon transmitter]] two miles away had been built some months earlier to broadcast [[ITV (TV network)|ITV]]. When [[Ultra high frequency|UHF]] transmissions started in 1964, first the new BBC2 and later (from 1969) both BBC 1 and ITV were transmitted from Crystal Palace. 405-line VHF television was discontinued at the start of 1985.<ref>{{cite web|url=https://ukfree.tv/maps/405lines|title=Black and white days, VHF bands I and III television|publisher=UK Free TV|access-date=16 May 2024}}</ref>
[[File:Stepped entrance to Crystal Palace Transmitting Station showing the original BBC coat of arms.jpg|alt=Stepped entrance to Crystal Palace Transmitting Station showing the original BBC coat of arms|thumb|Stepped entrance to Crystal Palace Transmitting Station showing the original BBC coat of arms]][[File:DM2025 Crystal Palace Transmitter with the Croydon transmitter in the distance.jpg|thumb|The Crystal Palace and Croydon (distant) towers aligned on the [[ Norwood Ridge]]]]
The station carried the London regions of [[BBC One]], [[BBC Two]], [[ITV (TV channel)|ITV1]] and Channel 4 in analogue, each with an [[effective radiated power]] of 1 MW, before digital switchover took place during April 2012, as well as all six [[digital terrestrial television]] [[multiplex (TV)|multiplexes]]. These had an [[effective radiated power]] of 20&nbsp;kW before switchover and 200&nbsp;kW after, with considerable [[beam tilt]] to the south and east. With digital switchover completed all services come from Crystal Palace again, but because of the site's importance Croydon will be able to duplicate the PSB multiplexes in case of emergency. [[Digital terrestrial television|DTT]] requires less power to achieve the same coverage as analogue TV, hence the transmission powers have been reduced by 7 [[decibel|dB]] compared to analogue;<ref>{{cite web | url=https://ukfree.tv/transmitters/tv/Crystal_Palace | title=Crystal Palace (Greater London, England) Full Freeview transmitter | date=May 2004 }}</ref> however, the coverage range of approximately {{convert|60|mi|km}} was expected to be largely similar post-switchover.<ref>{{cite web | url=http://tx.mb21.co.uk/mapsys/map.php?mapid=96 | title=Mb21 - Transmitter Information - Crystal Palace }}</ref>

===Radio===
It is also used for [[FM broadcasting|FM]] radio transmission of local radio stations [[BBC Radio London]], [[Radio X (United Kingdom)|Radio X]], [[Capital Xtra]] and [[Greatest Hits Radio|Greatest Hits Radio London]] (which until March 2021 carried [[Absolute Radio]]), and a low-powered relay of the four BBC national FM services - [[BBC Radio 1|Radio 1]], [[BBC Radio 2|Radio 2]], [[BBC Radio 3|Radio 3]] and [[BBC Radio 4|Radio 4]], and [[Classic FM (UK)|Classic FM]]. It also has [[medium wave]] transmitters on 558 [[Hertz|kHz]] ([[Panjab Radio]])) and 1035&nbsp;kHz ([[Lyca Radio|Lyca Gold]]). Since the tower is grounded, a wire aerial span close to it is used for the [[Medium wave|MW]] services.

Since 1995 the tower has been one of five London transmitters for the [[BBC]] [[Digital Audio Broadcasting|DAB]] [[multiplexing|multiplex]]. This was joined in 1999 by the [[Digital One]] DAB service, and a further local DAB multiplex has since started transmitting, on behalf of the [[Klarna]] shopping channel.

BBC Radio 4's mediumwave frequencies from this transmitter ended on 15 April 2024 following a retune loop informing listeners to retune.<ref>{{Cite AV media |url=https://www.youtube.com/watch?v=-z3kYvzXfEs |title=BBC Radio 4 ‘AM retune loop’ - 15/04/2024 |language=en |access-date=2024-04-15 |via=www.youtube.com}}</ref><ref>{{Cite web |date=2024-03-21 |title=Date set for the closure of BBC Radio 4 medium wave frequencies |url=https://radiotoday.co.uk/2024/03/date-set-for-the-closure-of-bbc-radio-4-medium-wave-frequencies/ |access-date=2024-03-28 |website=RadioToday |language=en-GB}}</ref>

===High definition===
In May 2006 it began broadcasting the first terrestrial [[High-definition television|HDTV]] signals in the UK to a trial group of 450 London homes to test HD broadcasts by the BBC, ITV, Channel 4 and Channel 5, to assess the viability and potential problems of future nationwide HD broadcasting. On 2 December 2009 the site entered service as one of the first [[DVB-T2]] transmitters in the world, carrying a variant of the BBC's Multiplex B broadcasting high-definition TV services.

===Digital switchover===
The Government's plans for [[digital switchover]] were based on the use of almost all current analogue TV transmitter sites. Crystal Palace remained a key part of the network after analogue was switched off in the London area in April 2012. In July 2007 it was confirmed by Ofcom that Crystal Palace would remain an A group transmitter after DSO (digital switchover). This was partially reversed with the 700&nbsp;MHz Clearance that resulted in the use of Channels 55 and 56 for digital television both outside the A Group.<ref name="700Mhzclearance">{{cite web |title=700MHz-Clearance |url=http://www.aerialsandtv.com/digitaltv.html#700MHz-Clearance |publisher=ATV |date=12 July 2017 |access-date=5 June 2018}}</ref>

The transmitter is only one of two (the other being the [[ITV Granada]] transmitter at [[Winter Hill (North West England)|Winter Hill]]) that alone provides [[ITV Network|ITV]] and [[BBC]] services for the whole of their region, although still supported by the usual network of relays. Between opening in 1974 and January 1982, the [[Bluebell Hill transmitting station|main transmitter]] at [[Bluebell Hill]] broadcast [[ITV London]] signals to much of north and central [[Kent]]. However, the [[Independent Broadcasting Authority]] (IBA), the then regulator of commercial television, reorganised the ITV franchises which saw Bluebell Hill transferred to a new south and south-east dual-region of ITV (Television South – TVS), which took effect from 1 January 1982. Bluebell Hill now transmits [[ITV Meridian]] and [[BBC South East]].{{citation needed|date=March 2021}}

As one would expect for the largest transmitter in the country – by population coverage – Crystal Palace transmitter remained an A group, (which was its original analogue group) both during dual running (analogue and low-power pre-DSO digital) and full-power digital after DSO. However, in March 2018, during the transmitter's 700&nbsp;MHz clearance, the temporary MUXES 7 and 8 were moved out of group to CH55 and CH56. Thus, reception of the latter two MUXES now requires a wideband or K group aerial (see [https://www.aerialsandtv.com/knowledge/transmitters/crystal-palace-transmitter#crystal-palace-transmitter-aerial-gain-graph graph]). MUXES 7 and 8 were, however, due to be switched off sometime before 2023.

On 18 April 2012, a public lighting display was performed from the tower to mark the last day of analogue TV broadcasts from the transmitter.<ref name="ArqivaSwitchOver">{{cite web |title=Switch Over Night |url=https://www.arqiva.com/corporate/digital-switch-over/digital-switch-over-london-region/switchovernight/ |website=Arqiva - Digital Switch Over |publisher=Arqiva |archive-url=https://web.archive.org/web/20130303031306/https://www.arqiva.com/corporate/digital-switch-over/digital-switch-over-london-region/switchovernight/ |archive-date=3 March 2013}}</ref><ref name="SwitchOverBlog">{{cite web |title=Arqiva lights up the skies! |url=http://www.arqiva.com/corporate/digital-switch-over/digital-switch-over-london-region/switchovernight/blog/ |website=DSO Switch Over Night Blog |publisher=Arqiva |archive-url=https://web.archive.org/web/20130101025843/http://www.arqiva.com/corporate/digital-switch-over/digital-switch-over-london-region/switchovernight/blog/ |archive-date=1 January 2013 |date=19 April 2012}}</ref><ref name="LocalGuardSwitchOver">{{cite news |title=Light show planned for Crystal Palace |url=https://www.yourlocalguardian.co.uk/news/9621648.light-show-planned-for-crystal-palace/ |access-date=12 July 2020 |work=Your Local Guardian |date=30 March 2012}}</ref>

===Relay stations===
The three most powerful relays are [[Reigate transmitting station|Reigate]] (covering a large area of south [[Surrey]] and northern areas of [[West Sussex]]), Guildford (for the [[Guildford]] area and parts of south west Surrey)<ref>{{cite web|url=https://ukfree.tv/transmitters/tv/Guildford|title=Full Freeview on the Guildford (Surrey, England) transmitter|date=1 May 2004|website=UK Free TV|accessdate=22 March 2024}}</ref> and Hemel Hempstead (parts of [[Hertfordshire]]). <ref>{{cite web|url=https://ukfree.tv/transmitters/tv/Hemel_Hempstead|title=Full Freeview on the Hemel Hempstead (Hertfordshire, England) transmitter|date=1 May 2004|website=UK Free TV|accessdate=22 March 2024}}</ref> There are also low-power relays situated across [[Greater London]] and also in parts of [[Kent]], [[West Sussex]], [[Surrey]], [[Oxfordshire]], [[Buckinghamshire]] and Hertfordshire.

==Channels listed by frequency==

===Analogue radio (AM medium wave)===
{| class="wikitable sortable"
!Frequency
!kW
!Service
|-
|558&nbsp;kHz
|1
|Panjab Radio
|-
|1035&nbsp;kHz
|2.5
|[[Lyca Radio|Lyca Gold]] (moved to west London)
|}

These frequencies were used by [[Lots Road Power Station|Lots Road]] until Tuesday 25 September 2001.

===Analogue radio (FM VHF)===
{| class="wikitable sortable"
!Frequency
!kW
!Service
|-
|88.8&nbsp;MHz
|4†
|[[BBC Radio 2]]
|-
|91.0&nbsp;MHz
|4†
|[[BBC Radio 3]]
|-
|93.2&nbsp;MHz
|4†
|[[BBC Radio 4]]
|-
|94.9&nbsp;MHz
|4
|[[BBC Radio London]]
|-
|96.9&nbsp;MHz
|0.03
|[[Capital Xtra]]
|-
|98.5&nbsp;MHz
|4†
|[[BBC Radio 1]]
|-
|100.6&nbsp;MHz
|2 (V)†
|[[Classic FM (UK)|Classic FM]]
|-
|104.9&nbsp;MHz
|2.9
|[[Radio X (United Kingdom)|Radio X]]
|-
|105.8&nbsp;MHz
|3.73
|[[Greatest Hits Radio|Greatest Hits Radio London]]
|}

† Relay of [[Wrotham transmitting station|Wrotham]].

===Digital radio (DAB)===
{| class="wikitable sortable"
!Frequency
!Block
!kW
!Operator
|-
|213.360&nbsp;MHz
|10C
|3
|[[MuxCo|MuxCo Surrey & South London]]
|-
|216.928&nbsp;MHz
|11A
|5.7
|[[Sound Digital]]
|-
|222.064&nbsp;MHz
|11D
|6.5
|[[Digital One]]
|-
|223.936&nbsp;MHz
|12A
|3
|[[Switch London]]
|-
|225.648&nbsp;MHz
|12B
|10
|[[BBC National DAB]]
|}

===Digital television===
{{col-start}}
{{col-2}}

====After switchover====
{| class="wikitable sortable"
!Frequency
!UHF
!kW
!Operator
!System
|-
|{{UK DVB-T|ch=22}}
|22
|200
|COM5 ([[Arqiva|ARQ]] A)
|[[DVB-T]]
|-
|{{UK DVB-T|ch=23}}
|23
|200
|PSB1 ([[BBC]] A)
|DVB-T
|-
|{{UK DVB-T|ch=25}}
|25
|200
|COM4 ([[S4C Digital Networks|SDN]])
|DVB-T
|-
|{{UK DVB-T|ch=26}}
|26
|200
|PSB2 ([[Digital 3&4|D3&4]])
|DVB-T
|-
|{{UK DVB-T|ch=28|off=neg}}
|28−
|200
|COM6 (ARQ B)
|DVB-T
|-
|{{UK DVB-T|ch=30|off=neg}}
|30−
|200
|PSB3 (BBC B)
|[[DVB-T2]]
|-
|{{UK DVB-T|ch=35}}
|35
|30
|LTVmux
|DVB-T
|}

{{col-2}}

====Before switchover====
{| class="wikitable sortable"
!{{no2}}Frequency
!{{no2}}UHF
!{{no2}}kW
!{{no2}}Operator
!{{no2}}System
|-
|{{UK DVB-T|ch=22|off=neg}}
|22−
|20
|[[Digital 3&4]] (Mux 2)
|[[DVB-T]]
|-
|{{UK DVB-T|ch=25|off=neg}}
|25−
|20
|[[BBC]] (Mux 1)
|DVB-T
|-
|{{UK DVB-T|ch=28|off=neg}}
|28−
|20
|BBC (Mux B)
|DVB-T
|-
|{{UK DVB-T|ch=29|off=neg}}
|29−
|20
|[[Arqiva]] (Mux D)
|DVB-T
|-
|{{UK DVB-T|ch=31}}
|31
|10
|BBC B (Mux HD)
|[[DVB-T2]]
|-
|{{UK DVB-T|ch=32|off=neg}}
|32−
|20
|[[S4C Digital Networks|SDN]] (Mux A)
|DVB-T
|-
|{{UK DVB-T|ch=34|off=pos}}
|34+
|20
|Arqiva (Mux C)
|DVB-T
|}

{{col-end}}

===Analogue television===
BBC2 analogue was shut down on UHF 33 on 4 April 2012, and ITV London was temporarily moved from UHF 23 into BBC2's frequency of UHF 33. The remaining  analogue services shut down on 18 April 2012.

{| class="wikitable sortable"
!{{no2}}Frequency
!{{no2}}UHF
!{{no2}}kW
!{{no2}}Service
|-
|{{UK System I|ch=23}}
|23
|1000
|ITV London
|-
|{{UK System I|ch=26}}
|26
|1000
|[[BBC1|BBC1 London]]
|-
|{{UK System I|ch=30}}
|30
|1000
|[[Channel 4]]
|-
|{{UK System I|ch=33}}
|33
|1000
|[[BBC2]]
|}

==See also==
{{portal|London}}
* [[List of radio stations in the United Kingdom]]
* [[List of tallest buildings and structures in Great Britain]]
* [[List of tallest towers in the world]]
* [[List of famous transmission sites]]
* [[Radio masts and towers]]
* [[Lattice tower]]

==References==
{{reflist}}

==Bibliography==
*Burns, R. W., ''British Television: The Formative Years'', IET (1986), {{ISBN|0-86341-079-0}}
*Evans, R. H., ''The Crystal Palace FM filler experiment'', British Broadcasting Corporation, Division of Engineering, Research and Development Department (1996), ASIN B0018RJ1ZY

==External links==
{{Commons category|Crystal Palace Transmitter}}
*[https://web.archive.org/web/20191018064838/http://tx.mb21.co.uk/gallery/crystalpalace/ The Transmission Gallery: Crystal Palace Transmitter photographs and information]
*[https://www.aerialsandtv.com/knowledge/transmitters/crystal-palace-transmitter Pictures and info on Crystal Palace, including co-receivable transmitters]
*{{SkyscraperPage|3886|Crystal Palace Transmitter}}
*[http://www.thebigtower.com/live/CrystalPalace/Index.htm Crystal Palace Transmitter at thebigtower.com]
*[http://thetrianglese19.blogspot.co.uk/2015/01/the-transmitter.html Pictures (including inside the transmitter buildings) at The Triangle]

{{Television transmitters in the UK}}
{{Crystal_Palace_VHF_405-line_Transmitter Group}}
{{Supertall}}
{{London landmarks}}

[[Category:Lattice towers]]
[[Category:Buildings and structures in the London Borough of Bromley]]
[[Category:Crystal Palace, London]]
[[Category:History of television in the United Kingdom]]
[[Category:Infrastructure in London]]
[[Category:Radio in the United Kingdom]]
[[Category:Television in the United Kingdom]]
[[Category:Transmitter sites in England]]
[[Category:Media and communications in the London Borough of Bromley]]
[[Category:1956 establishments in England]]
[[Category:Towers completed in 1956]]
[[Category:Infrastructure completed in 1956]]