THE TRANSMISSION GALLERY
|Photos by Various||Page last updated: 2021-12-01|
|On 10 August 2021 a fire broke out in one of the transmitter buildings close to the base of the mast. The onsite engineer called the fire brigade at 1319 stating that he could see smoke coming from below the first stay level, around 50–60 metres from the ground. A local hill walker also noticed a huge black cloud of smoke coming from one of the buildings at the base of the mast, with smoke coming out of the top "a bit like a chimney".|
Eight pumps from North Yorkshire Fire and Rescue Service attended and "worked to control the fire in difficult circumstances and extinguished a fire in a single-storey stone building and transmitter mast." Only one of the four buildings at the mast was affected.
The fire took all services off air. Survey work was undertaken by drones to ascertain structural stability, and a 300m exclusion area was put in place. The mast was subsequently deemed structurally unsound and was demolished on 6 October (see video link at bottom of page).
All services, including digital TV, DAB, BBC national, BBC local and commercial FM radio were put off air for a considerable period. Bilsdale is an important site, providing over 1 million people with TV and radio services in an area stretching from Hartlepool in the north to York and Harrogate in the south, most of North Yorkshire, including Stockton, Middlesborough and Whitby.
In order to restore services to as many people as possible as quickly as possible, emergency work at the Eston Nab relay was immediately undertaken. On 11 August the three TV PSB transmitters were retuned from their normal allocations of 23/26/48 to the Bilsdale allocations of 27/24/21, the transmit log periodic antennas were changed from vertical to horizontal polarisation, the receive (RBL) antenna was swung around to point at Pontop Pike, and the transmitter powers were doubled from 10W to 20W. This action restored PSB services to viewers in Hartlepool, Redcar and the eastern edges of Middlesbrough, although all viewers who were using Eston Nab prior to this change then needed to retune their equipment. Subsequently on 12 August a temporary mast and additional transmitters were installed, allowing the PSB services to be transmitted at higher power over a larger area on the Bilsdale channel allocations. The existing Eston Nab transmitters were then tuned back to their original allocations and repurposed to broadcast the three COM services. It was not possible to use the Bilsdale allocations for the COM services as they are adjacent channel to the incoming feed from Pontop Pike. Transmissions from the temporary mast were increased in power on 19 August extending coverage to over 250,000 households. Radio services for Radio Tees (95.0 MHz) and TFM Radio (96.6 MHz) were installed on 11 & 12 August, and the other commercial radio services were then added on 13 August: Heart FM (North East) on 100.7 MHz, Capital FM (North East) on 106.4 MHz, and Classic FM on 101.6 MHz, thus restoring all local radio services to the majority of their previous audience. Although Eston Nab was originally primarily a low power television relay, the FM radio installation covers a wide area, including Hartlepool, Stockton, Middlesborough, Guisborough, Darlington and Scotch Corner. On 17 August DAB services for Digital 1 and SDL were also added.
A temporary 15m mast was erected at the BT Microwave site at Arncliffe Wood on 20 August, with transmissions commencing later that same day. This measure restored reception to the areas around Darlington, Barnard Castle, Richmond, Leyburn, Catterick, Masham and Ripon. PSB services are on channels 40, 43 & 46, so viewers will need to retune their equipment.
A temporary site at Sutton Bank commenced transmissions on 8 September extending coverage to Northern parts of York, Harrogate, Pickering, Ripon, Masham and Leyburn. PSB services were on channels 27, 24 & 21. This was discontinued on 13 October when the temporary mast at Bilsdale Quarry came into service.
TV services at Bilsdale's biggest dependent relays Whitby, Guisborough and Limber Hill have been restored on 13 August, either by changing the RBL from Bilsdale to Pontop Pike, or in the case of Whitby for PSB 1 & 3 by changing the feed to D-Sat 27.5W. The same is also likely to have happened at Guisborough. BBC Tees on 95.8 MHz from Whitby, which was also dependent on Bilsdale, has also been restored. Services from Peterlee were restored on 18 August, again by changing the incoming feed to Pontop Pike. Skinningrove was put back on the air on 20 August, initially only the PSB2 multiplex with the other PSB services following shortly after.
The remaining Bilsdale relays were gradually restored by changing their RBL feeds to Pontop Pike or satellite. This was completed on 3rd September when the Rosedale Abbey relay returned to air. A temporary transmitter has also been added for Radio Tees on 104.0 MHz at Darlington (Patches Lane) also known as Beaumont Hill. This covers Darlington and surrounding areas.
The next stage of recovery was to install a temporary mast at Bilsdale Quarry, just to the south of the main Bilsdale site, which is expected to restore TV services to about 95% of viewers. A 80m mast has been erected at a nearby disused quarry site, and despite some initial delays due to the legal/planning process and bad weather transmissions from this site came into service on 13 October. This mast will remain in service until a second more substantial tower (also 80m in height) can be built. Planning consent for this was granted on 25th October. It is hoped that the tower will be constructed and on air before the winter months set in, as the temporary mast is not designed to survive the harsh conditions on the moor at that time of year. The mast is not that substantial and the stay anchors are only concrete blocks resting on the ground.
These works are no simple endeavour, given that the area is a Site of Special Scientific Interest which is valued for a mix of habitats of rare fauna and flora. Ground needs to be prepared, power cables run, temporary transmitter units and feeders installed. It should be borne in mind however that the replacement structures will be 240m shorter than the old mast, so a reduction in coverage area will be inevitable. The extent of this reduction is currently being assessed, and Arqiva have published a map showing the areas predicted still to have no signal now Bilsdale Quarry is in service.
The areas shown in red are likely to remain unserved by the new mast. This includes areas on the coast, the Dales of North Yorkshire and County Durham, and some other areas. It is understood that Arqiva is now looking at whether some additional temporary transmitters might be installed to cover these areas. The first two of these entered service on the 30th and 31st October to serve Loftus and Thirsk respectively. Another was added at Kirkbymoorside on 29th November, also from the same date a horizontally polarised beam has been added at Bainbridge.
The final phase is the restoration of a service approximately equivalent to that prior to the incident. The fire damaged mast was demolished on 6-Oct-2021, see the link at the base of this page for a video of the demolition. It is envisaged that a new mast of a similar height to the old one will eventually be built, but timings for this are currently not known.
|Image credit: DB Aerial & Satellite, Hartlepool|
The remaining pictures were taken by Martin Brown on the 20th, 10 days after the fire.
|Starting at the bottom|
|The first stay level|
|This is the area southwest of the main site, where I understand the temporary mast is to be sited. Just a solitary digger on the site on the afternoon of Friday 20th.|
Arqiva Bilsdale update 8-Sep-2021 (YouTube video)
Arqiva Bilsdale update 17-Sep-2021 (YouTube video)
Bilsdale Mast Restoration - Exploring The Technicalities
Bilsdale Incident: Temporary Mast Construction
Mast demolition 6-Oct-2021 (YouTube video)
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