Winter Hill Mast is a television mast situated between Chorley and Bolton, in Lancashire, England.
The mast is 1015' 4" high and transmits to an area of approximately 50 miles in radius, and after a period of BBC ownership, is now owned and maintained by NTL. It is the tallest manned mast in the country (the tower at Belmont is taller, but unmanned).
Construction
Unlike most masts, which are of a frame design, Winter Hill mast is of a tubular construction. 5 other masts in England share this design (Belmont, Bilsdale, Mendip, Waltham and the orginal 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. These wires have recenly been strengthened (and dampened) by NTL, presumably to prevent the mast collapsing in the manner of Emley Moor's original structure.
Maintenance
An advantage of the tublar 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 bosuns chair .
A series of red lights shine continuosly to warn aeroplanes of the masts presence, and to let people in the vicinity be aware of the danger of falling ice, which is quite common due to the altitude and winds. 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 transmitters.
Output
The telivision output is NICAM, horizontally polarized, 500KW per station Effective Radiated Power.
BBC1 - UHF channel 55
BBC2 - UHF channel 62
ITV - UHF channel 59
Channel 4 - UHF channel 65
Channel 5 - UHF channel 48
Freeview transmissions are also broadcast; the transmission power is not common knowledge.
Plane Crash
On the 27th February 1958, a passenger jet travelling from the Isle Of Man to Manchester crashed into Winter Hill (previously 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 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 - VHF 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.
1998 - Century FM radio start broadcasting from the main mast.
