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Winter Hill
Winterhillmast.jpg
Click to view the hi-res version and see the supporting cables
Height of mast 315.4 metres (1,035 ft)
Grid reference SD660145
BBC region BBC North West
ITV region ITV Granada
Analogue switch-off 4 November 2009 (Stage 1)
2 December 2009 (Stage 2)

The Winter Hill transmitting station is a broadcasting and telecommunications site situated on Winter Hill, at the southern boundary of the Borough of Chorley, and above Bolton in Greater Manchester, England. It is owned and operated by Arqiva.

Contents

Height

The original mast at Winter Hill was a 450ft high tower which came into service on May 3, 1956, and carried the programmes of Granada ITV (weekdays) and ABC TV (weekends).In 1966 services were transferred to a new higher mast erected adjacent to the original tower.The main mast structure is {{convert|309.48|m|ft|} tall and has a diameter of 2.75 metres (9.0 ft). During the period of parallel digital and analogue transmissions, the DTT antenna attached to the top of the mast brought the overall height to 315.4 metres (1,035 ft)[1], however as part of the Digital Switchover plans, this antenna has now been removed, reducing its overall height to 309.48 metres (1,015.4 ft)[1]. It is one of the tallest structures in the United Kingdom, the tallest being the mast at Belmont with a height of 387.75 metres (1,272.1 ft), however at 778.1 metres (2,553 ft) above sea level, Winter Hill has the highest television transmitting antenna in the UK.

Construction

A view of the mast from beneath, illustrating the tubular structure

Unlike most masts, which are of a lattice design, Winter Hill mast is of a tubular construction. Five other masts in England share this design (Belmont, Bilsdale, Mendip, Waltham and the original ill-fated structure at Emley Moor). Support wires, to hold the mast vertical, are pitched at 120° when viewed from above. These are connected at 5 heights, giving 15 supports in total. In recent years, these wires have been strengthened, and 152 metric tons (150 tons) of dampening chains have been fitted by Arqiva (then NTL Broadcast) to reduce the oscillations caused by high winds that were a factor in the collapse of Emley Moor's original structure in 1969[2].

Maintenance

An advantage of the tubular design is that engineers can ascend the inside of the mast and not be subject to adverse weather, which is a problem on frame structures. Maintaining the outside of the mast is typically performed using a bosun's chair.

The mast has always had a series of red aircraft warning lights but in October 2006 these lights were substantially brightened making the mast far more visible to passing aircraft. These lights can be maintained from the inside, as the bulbs swing inwards for maintenance.

Eight external platforms encircle the mast along its height, these can be accessed from the inside of the mast, and are used to maintain the supporting wires, and the ILR antennas.

Coverage

The station's coverage includes approximately 6.3 million people. Although not the 'correct' television region, it is the preferred region for some in North Wales, mainly because it carries Channel 4 (as opposed to S4C), Five and a much more powerful digital terrestrial output than the Welsh transmitters. The region's ITV franchisee, Granada Television (which launched in 1956), was also on air much earlier than North Wales' franchisee, WWN (Teledu Cymru) (which launched 1962), giving viewers more choice than they would with the Welsh transmissions. After digital switchover, the Welsh transmitters will be broadcasting DTT at a much higher power than present, of which Channel 4 and Five are included in the line-up. However, because of terrain and rough landscapes of North Wales, many will find it easier to stay with Winter Hill (as small local relays will only broadcast a limited range of the digital channels). In July 2007 it was confirmed by Ofcom that Winter Hill would be remaining a C/D group transmitter after DSO (digital switchover).

Output

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Television

Digital television

Only digital terrestrial television transmissions are carried from the site since 2 December 2009. Five of the six multiplexes are at 100kw, but MUX6/Arqiva B (on channel 55) will only be transmitted at 12.5 kW until September 2011 due to co-channel interference issues with the Sutton Coldfield transmitting station's MUX6/Arquiva B which is also on channel 55.

As principal transmitter for the Granada region, in 2009 Winter Hill became the first in the UK to broadcast digital television in high-definition.[3][4]

Analogue television transmissions from Winter Hill ceased officially at 00:12 GMT on the morning of 2 December 2009. The stations began to disappear from 23:57 on 1 December, with the loss of BBC One. This was followed on 2 December by Channel 4 at 00:03 GMT, ITV1 at 00:06 GMT and finally Five at 00:12 GMT.[5] The transmitting station now only broadcasts digital terrestrial television signals.

Radio

FM

† 4KW Relays the signal from Holme Moss to cover South and Central Lancashire [6]

DAB

  • CE Manchester: 11C - 220.352 MHz (250 watts)

CE Manchester broadcasts from a directional aerial to cover Greater Manchester)

(EMAP Central Lancashire broadcasts from a directional aerial to cover Central Lancashire (Wigan, Preston, Southport, Blackpool and surrounding areas))

[6] [7]

Plane crash

On 27 February 1958, a Silver City Bristol 170 Freighter (G-AICS) travelling from the Isle of Man to Manchester crashed into Winter Hill (also known as Rivington Moor) several hundred yards away from the mast. 35 people died and 7 were injured. The weather that night was so severe that none of the engineers working in the transmission centre were aware of the crash. Several feet of snow hampered rescue efforts, and a snow cat vehicle had to be diverted from the A6 to cut a path for emergency vehicles.

Timeline

  • 1956: Granada Television commences black and white television broadcasting prior to main mast construction.
  • 1958: Fatal plane crash kills 35 people, 7 survive.
  • 1962: BBC commence broadcasting.
  • 1965: Main mast is completed, replacing the old 450' construction, which is removed.
  • 1966: UHF transmissions start.
  • 1968: ITV build the single storey engineering building.
  • 1969: ITV and BBC transmit in UHF.
  • 1970: Relaying service set up with Emley Moor mast.
  • 1974: Local radio stations set up wire frame ILR transmitters on the hill.
  • 1981: Channel 4 create additional engineering building.
  • 1982: Additional ILR transmitter put into operation for further local radio. Channel 4 commences transmission.
  • 1983: Channel 4 set up relay service.
  • 1997: Channel 5 commences transmission
  • 1998: Century FM radio start broadcasting from the main mast.
  • 2009: Analogue TV signals were switched off in two phases on Wednesday 4 November 2009 (BBC Two Switched off) and 2 December 2009 (remaining analogue channels).[8]

See also

References

Further reading

  • The Devil Casts His Net, Steve Morrin, ISBN 0-9534503-1-7, The Winter Hill Air Disaster.

External links

Coordinates: 53°37′32″N 2°30′53″W / 53.62556°N 2.51472°W / 53.62556; -2.51472


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