Winter Hill transmitting stationEdit profile
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.Height
The original mast at Winter Hill was a 450 ft high tower which came into service on 3 May 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 309.48 metres (1,015.4 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), 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). It is one of the tallest structures in the United Kingdom, the tallest being the mast at Belmont with a height of 351.5 metres (1,153 ft), however at 778.1 metres (2,553 ft) above sea level, Winter Hill has the highest television transmitting antenna in the UK.Construction
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.Maintenance
An advantage of the tubular design is that engineers can ascend the inside the mast and avoid 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), Channel 5 and a much more powerful digital terrestrial output than the Welsh transmitters. The region's ITV franchisees, Granada Television (weekdays only until 1968) and ABC Television (Associated British Corporation) weekends (launched in 1956), were on air much earlier than North Wales' franchisee, WWN (Teledu Cymru) which launched in 1962 (subsequently HTV Wales) giving viewers more choice than they would with the Welsh transmissions. ABC Television lost its franchise in 1968, when Granada Television commenced broadcasting seven days a week. Since the digital switchover, the Welsh transmitters are broadcasting DTT at a much higher power and Channel 4 & Channel 5 are now 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). One of the Winter Hill Multiplexes (Arqiva B or MUX6), broadcasting channels including Film4 & ITV4, will be on reduced power (12.5 kW) until Sutton Coldfield goes fully digital in September 2011. This compares with the other Winter Hill digital multiplexes which have broadcast with 100 kW since 2 December 2009. This will significantly affect the Arqiva B multiplex coverage area until the Sutton Coldfield final switchover date.
Apart from North Wales, the coverage area is what is expected, covering a large area of the north-west. More Relay Transmitters appear towards the east in Greater Manchester.Output
Only digital terrestrial television transmissions are carried from the site since 2 December 2009. Five of the six multiplexes are at 100 kW, 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.
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 Channel 5 at 00:12 GMT. The transmitting station now only broadcasts digital terrestrial television signals.
Only 4 of the 70 Winter Hill relays will broadcast six digital multiplexes (Lancaster, Saddleworth, Pendle Forest and Storeton). All the others will broadcast just the three public service multiplexes BBC A, BBC B and D3&4. Since switchover BBC B is reserved for HD broadcasts only. Winter Hill also broadcasts a Manchester Multiplex on Channel 57 which includes Channel M.Radio
† Relays the signal from Holme Moss to cover South and Central Lancashire
† Broadcasts from a directional aerial to cover Greater Manchester.
‡ Broadcasts from a directional aerial to cover Central Lancashire (Wigan, Preston, Southport, Blackpool and surrounding areas).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 weekdays & ABC Television (Associated British Corporation) weekends commence 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: ABC Television loses franchise; Granada Television commences broadcasting seven days a week.
- 1968: ITV build the single storey engineering building.
- 1969: ITV and BBC transmit in colour on 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 starts broadcasting from the main mast (now Real Radio).
- 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).