Kirk o' Shotts

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Kirk o' Shotts is the site of a television transmitter near the village of Harthill in North Lanarkshire, almost midway between Edinburgh and Glasgow.

Development

BBC TV rollout programme

There were five main stations in the BBC's national television network.

London and Birmingham were the locations of the first transmitters. With the completion of the next three developments the BBC was able to cover about 78 per cent of the population of the United Kingdom by the end of 1952, giving Great Britain the most comprehensive television coverage in the world.

Date Name Coverage area Location Power Reception range
2 Nov 1936–1 Sep 1939
Resumed 7 Jun 1946
Alexandra Palace London London
17 December 1949 Sutton Coldfield Midlands Birmingham 35kw
12 October 1951 Holme Moss North of England Manchester/Huddersfield 45kw
14 March 1952 Kirk o' Shotts Central Scotland Harthill 50kw 4m (3m until 17 Aug during period of medium-power)
15 August 1952 Wenvoe South Wales & SW England Cardiff 4.5m people. Like Kirk o' Shotts it initially began transmitting on medium power.


The addition of five low-power stations would bring TV within the reach of 40,750,000 — or 80 per cent of the British population by the end of 1954. Construction was initially postponed, however, because of the need for national economy.


  • Aberdeen — mid-1953.

The BBC decided that, in its initial stages, the Kirk o' Shotts station would broadcast for the most part the same programme as Alexandra Palace. The visual signals would come from London via Birmingham and Manchester, and then to Scotland using the new method of a radio link installed by the General Post Office (GPO). The estimated cost of the radio link between Manchester and Kirk o' Shotts was about £520,000.[1] This, it was later estimated, worked out at £2,424 a mile.[2]

An outside broadcast unit was allocated for use in Scotland and North-East England. Consisting of three vehicles and a team of producers and technicians, the unit enabled Scottish occasions to be seen by viewers in Central Scotland and elsewhere.[3]

Site selection

After an extensive search by BBC engineers for a suitable site, an experimental mobile television transmitter mast was erected at North Hirst Farm at Harthill in Lanarkshire (known as 'Kirk o' Shotts') on Saturday 16 July 1949. Signals were transmitted from the 110ft high mast and mobile instruments traced their course and ascertained the area covered by them.[4]

After three months' experimenting, the BBC was negotiating for the purchase of 25 acres of ground at North Hirst Farm and eight acres on the adjoining Dewshill Farm.

The exact site chosen for the permanent transmitter was 900 feet above sea level, 17 miles from Glasgow and 28 from Edinburgh on the Edinburgh-Glasgow road. The buildings and the mast were not erected on the top of the hill at Kirk o' Shotts as had been originally planned, but 50 feet lower so as to avoid a peat bank 8 or 12 feet deep at the top.[5]

By December 1949, the Postmaster-General, Wilfred Paling, approved the site at Kirk o' Shotts and announced that preliminary planning of the station had begun, although building work would not be started until the middle of 1951. On his heels C. R. Hobson, the assistant Postmaster-General, promised that if in the 1951 programme there was capital investment for television Scotland would get the next station.

Radio relay link

The planning and engineering effort required to extend television coverage across the UK was considerable. Unlike radio, which used the Post Office telephone circuits, the additional bandwidth of television called for a dedicated network of underground coaxial cable, which had to be laid near main roads and the signal boosted by a relay station every six miles. Programmes were carried from London to Birmingham and then on to Manchester in this way. However, with growing pressure on the authorities to extend television to Scotland as soon as possible, it was decided as early as 1949 that extending the cable to Scotland would take too long. Instead, the final 246 miles from Manchester to Kirk o’ Shotts was completed using a pioneering broadband radio relay link — the first of its kind in Britain.

Using a method similar to relaying outside broadcasts to BBC transmitters, a chain of seven hilltop beacons (two of which were located in Scotland) were erected within line-of-sight of each other. The steel-latticed masts supported four parabolic reflectors, each 10ft in diameter and weighing 15cwt, which directed the television signal in the required direction from one beacon to the next.

The beacons were unattended, but in order that GPO engineers could access them for maintenance they were routed up the East coast of the country because meteorological records showed that the danger of snow blocks was less than on the West coast or through the Midlands and across the Lammermoor Hills.

An article in the Glasgow Herald in 1952 described the system:

On the first part of the journey to Scotland the television programmes from London are carried to Birmingham and thence to Manchester by underground cable. At Telephone House, Manchester, the signal is directed 13 miles north-east to a beacon at Windy Hill, the first of seven intermediary hilltop beacons in the radio link to Scotland.

From there, the signal was passed for 23 miles to the next beacon at Tinshill, north-west of Leeds; thence 40 miles to Arncliffe Wood, near Northallerton, another 39 miles to Pontop Pike, south-west of Newcastle, and from there 30 miles farther on to the last beacon in England at Corby's Crags, near Alnwick.

The next stage of 48 miles, the greatest distance between any two beacons in the chain, takes the signal across the Border to a beacon at Blackcastle Hill, near Dunbar. It is then directed westwards for 28 miles to Blackford Hill, Edinburgh, and finally over 25 miles to Kirk o' Shotts.

At Kirk o' Shotts the signal is fed into the GPO station where its frequency is reduced before being passed on to the BBC's building near-by. From there, after amplification, it is broadcast.

Construction of the radio chain took about two years.[6]

A provisional estimate put the capital cost per mile from Manchester to Kirk o' Shotts at £2,424. Over a distance of 248 miles this worked out at £601,152. For the whole link the BBC would pay the Post Office an annual rental provisionally estimated at £100,000, which took into account the expected life of the plant.

For comparison, the provisional estimate of the capital cost per mile from London to Manchester was £4,482. The distance involved was 247 miles. For the whole link the BBC would pay the Post Office an annual rental provisionally estimated at £90,000, which took into account the expected life of the plan.[7]

Key dates

In January 1950 permission was granted by the Civic Amenities Committee of Edinburgh Town Council to the Ministry of Works to erect an experimental radio beacon on the city's Blackford Hill.[8]

That same month the BBC issued contracts for the works at Kirk o' Shotts. Orders were placed with Electric and Musical Industries (EMI) for a 50 kilowatt vision transmitter, and with Standard Telephones and Cables for the associated 12 kilowatt sound transmitter.[9] The 750-foot mast was to be constructed and erected by British Insulated Callender's Construction Company Ltd, London, and the contract for the site works and the construction of the approach roads was awarded to Messrs McLean and Co, Wishaw.[10]

In March 1950 the BBC made a public announcement confirming that its first Scottish television transmitter would be built at Kirk o' Shotts and be ready by about the end of 1951. It also announced that it would later build a low-powered transmitter in Aberdeenshire.[11]

However, it was not until 10 May 1950 that Lanark County Council finally approved the BBC's plans for the erection of 'a television transmitting stations and electrical sub-station and garage' at Kirk o' Shotts. A minute of the planning committee stated that the buildings would be of one storey and would be situated on the south side of the Glasgow-Edinburgh road.[12]

Work on preparing the Kirk o' Shotts site began on 20 June 1950 and the site was cleared by August.[13]

In September 1950, construction of the microwave broad band radio relay link started.[14]

Transmitter design

In June 1951, a press party was invited to Kirk o' Shotts to inspect on the progress of the building works. The Glasgow Herald gave a detailed account of the 750 ft transmitter mast:

When completed the mast will have an 'all up' weight of more than 100 tons. For the first 610ft the cross-section is triangular, each face being 9ft wide; above that there will be a cylindrical section 100ft high and 6½ft in diameter; and finally a tapering, square-section topmast 40ft high, to which will be fixed the transmitting aerial.

The mast is held upright by four sets of stays of pre-stressed steel wire rope. The base is located by a small steel ball mounted in a socket, forming a pivot which allows the mast some movement in high winds. The sway may be as much as 7ft in any direction — 14ft in all [...]

The guy ropes for the completed mast will be attached to nine anchor blocks sunk seven or eight feet into the ground and containing in all 450 tons of concrete. The mast itself also stands on reinforced concrete.

The transmitting aerial will consist of eight vertical dipoles arranged in two tiers, each dipole having a built-in electric heater to prevent the surfaces from being covered by ice or snow.[15]

In a completely separate installation, housed in an annexe, an auxiliary mast, 150 feet high and with medium-powered aerials, served as a reserve in case of a breakdown at the main transmitter. The emergency aerials were fed with a separate supply of electricity and switches were provided to enable a rapid changeover from the main to the stand-by system.

Transmitter building

The building surrounding the transmitter was described as follows:

The main BBC building contains offices, a canteen, quality checking-room, power distribution switchgear, and accommodation for the high-power transmitters in the process of being installed. It is similar in design to the stations at Sutton Coldfield and Holme Moss and is built of local Scottish brick relieved with stone dressings. The roof Is formed from pre-cast hollow beams covered with a screed of concrete, a special roofing felt, and finished with tarmacadam. All inside doors are flush panelled and the external doors and window frames are of metal. The station is connected to the public water supply but has its own drainage system.[16]

Coverage area

Before Kirk o' Shotts came into service, the BBC estimated that the area of reliable reception would be bounded by a line through Wemyss Bay, Aberfoyle, Aberfeldy, Kirriemuir, and Arbroath in the north; and through Turnberry Point, Old Cumnock, Selkirk, Melrose, and Cockburnspath in the south — a region with a population of more than 3,500,000.

Whether or not reception was satisfactory at any particular place near the boundary was impossible to predict as it depended on several local factors, including the height of the receiving aerial and the strength of electrical interference in the vicinity.[17]

However, many viewers in the South of Scotland not within reliable range of Kirk o' Shotts were able nonetheless to obtain a signal from the Holme Moss transmitter near Huddersfield.[18]

Medium-power test transmissions

The first signal to be sent out from the medium-powered transmitter at Kirk o' Shotts came unexpectedly on Monday 17 December 1951, consisting of lines in a black-bordered square. The following day a sustained image of the Maltese cross was transmitted. Very few people saw these pictures as most sets at the time were owned by dealers and no pre-announcement had been made by the BBC.[19] Steady and clear signals were received as far north as Pitlochry which, because of the hills, it was feared might fall outside the range of the transmitter.[20]

It was estimated that the medium-power transmissions would bring satisfactory pictures to three-quarters of those within the full high-power service area, although the signals were more susceptible to interference than with full power. Nonetheless, in Glasgow, Edinburgh, and many other places in Central Scotland, it was difficult to recognise any difference between the medium and high-power transmissions.[21]

Regular tests were carried out on a daily basis (not including weekends) from Tuesday 15 January 1952 at 11 am and 3 pm. The hour-long transmissions began with the display of a large cross followed by a series of straight and diagonal lines with a centre circle. This allowed dealers and mechanics to examine reception and make adjustments. Owners of television sets, however, were advised by dealers not to leave them switched on for the two hours each day because the still images could become indelibly imprinted on the screen, possibly necessitating a replacement of the most expensive component in the set. Good reception was reported from towns including Dumfries, Kilmarnock, Edinburgh, and even Wooler in Northumberland where the Pennine barrier between them and the Lancashire transmitter at Holme Moss made reception from Kirk o' Shotts more reliable.[22]

King's funeral broadcast

The radio chain was ready just in time for the King's funeral procession on 14 February 1952. Scottish viewers were advised to switch on their sets from 9.15–10.05 am, and from 1.10–2 pm.

Thereafter, transmissions reverted to the daily test card. One exception came on 11 March 1952 when parts of two programmes from London were broadcast. The first pictures, picked up about 3.40 pm, showed the end of 'Roll up the Carpet', a dancing exhibition by Sydney and Mary Thomson which concluded the women's programme Leisure and Pleasure. Most of the Andy Pandy puppet programme which followed was also shown. Reception was reported as excellent, much better than during the King's funeral broadcast.[23]

Official launch

Television officially launched in Scotland on Friday 14 March 1952, but as the main high-power transmitter was not ready on time, for the first few months the service was broadcast from the ancillary medium-power transmitter, which had a potential audience conservatively estimated at 3 million.

High-power transmitter launch

The high-power transmitters at Kirk o' Shotts came into service on Thursday 14 August 1952, extending the potential audience from 3 to 4 million viewers (again, a conservative estimate). To allow for any adjustments to television receivers, for the first few days' of operation they were only used for the morning trade transmissions and the afternoon programmes, including Children's Hour, while evening transmissions continued to be radiated from the medium-power transmitters.

The high-power transmitters came into full-time operation on the evening of Sunday 17 August, co-inciding with the televised opening of the Edinburgh International Festival.[24]

References

  1. 'Television Link', Glasgow Herald, 15 November 1951, 6.
  2. 'High Power From Kirk o' Shotts', Glasgow Herald, 7 August 1952, 4.
  3. 'Good Progress with Scots TV Station', Glasgow Herald, 2 June 1951, 4.
  4. 'Television Site in Scotland: Lanarkshire experiment', Glasgow Herald, 18 July 1949, 5. See also 'How Television Came to Scotland', Glasgow Herald, 14 March 1952, 4.
  5. 'Good Progress with Scots TV Station', Glasgow Herald, 2 June 1951, 4.
  6. 'TV Beacon Link to Scotland', Glasgow Herald, 16 February 1952, 2.
  7. 'Cost of Bringing TV to Scotland', Glasgow Herald, 5 July 1952, 6.
  8. 'TV Experiment in Edinburgh', Glasgow Herald, 25 January 1950, 8.
  9. 'Scots TV Service Development: equipment order', Glasgow Herald, 31 January 1950, 4.
  10. 'Work at New Scots TV Station', Glasgow Herald, 23 May 1950, 4.
  11. 'Television Plans for Scotland: statement by BBC', Glasgow Herald, 17 March 1950, 5.
  12. 'Television Plan Approved', Glasgow Herald, 11 May 1950, 6.
  13. 'Work Begun on Scots Television Site', Glasgow Herald, 20 July 1950, 5; Untitled article, Glasgow Herald, 12 August 1950, 6.
  14. 'How Television Came To Scotland', Glasgow Herald, 14 March 1952, 4.
  15. 'Good Progress with Scots TV Station', Glasgow Herald, 2 June 1951, 4.
  16. 'Kirk o' Shotts transmitter', Glasgow Herald, 14 March 1952, 4.
  17. 'Good Progress with Scots TV Station', Glasgow Herald, 2 June 1951, 4.
  18. 'Increasing Range of Television', Glasgow Herald, 11 October 1951, 7.
  19. 'Kirk o' Shotts Makes First Signals', Glasgow Herald, 19 December 1951, 5.
  20. 'TV Received at Pitlochry', Glasgow Herald, 22 December 1951, 6.
  21. 'Low-Power TV Will Be Satisfactory', Glasgow Herald, 14 January 1952, 3.
  22. 'Kirk o' Shotts Tests Satisfactory', Glasgow Herald, 16 January 1952, 4.
  23. 'Good Reception in Scots TV Tests', Glasgow Herald, 12 March 1952, 4.
  24. 'Kirk o' Shotts Transmitters: installations complete', Glasgow Herald, 13 August 1952, 3.