Annual report 2010

Quick Links

Engineering programme

How more than 1,150 transmitters are being upgraded to boost digital coverage to the whole UK

Interviews

Show transcript

It is the biggest engineering project in television terms since the network was originally constructed, which started roughly fifty years ago. We are re-engineering over 1000 transmitters over a period of about six years. This involves a variety of engineering activities from, at the one extreme re-building complete 300 metre masts, to dealing with small relay stations which are effectively telegraph poles and it roughly splits out between a hundred, what we call, larger main stations and about a thousand of the smaller relays.

During the course of the engineering works we do our best to minimise the disruption to viewers, however, with a project of this scale it’s impossible not to cause some impacts. This will vary very much from place to place depending on what we are having to do at the local transmitter. In some cases we have actually had to move services onto temporary masts in order to enable the engineering work to take place. Each time we do that it does cause subtle differences to the radiation pattern of the services, so some people will notice differences. Other people will see temporary interruption to the service, short service breaks, but we do do our best to communicate those to people in advance so that they understand that this is part of the normal process.

During the last year, one of the big events was the switchover of the Granada region, which from an engineering perspective was a challenge because of the scale of activity that had to take place all on one night; something like sixty-four transmitters had to be switched over within a period of about twelve hours. Fortunately that went well and a lot of experience was gained from that activity.

Generally speaking, the challenge for us, in working ahead of the switchover programme and preparing the engineering, is the vulnerability to bad weather. We had a couple of bad summers early in the programme, which created a bit of a back-log but fortunately in the last year we have caught up on that and we are on track to complete the programme. However, we did suffer some unexpected problems in Scotland earlier in the year with very deep snow which meant there was a period of four to six weeks where even with four by four wheel drive vehicles, it wasn’t possible to access the sites. But fortunately, that snow’s gone and we’re now back on schedule.

One of the other aspects of the broadcast work stream activity has been the creation, in conjunction with our colleagues at the BBC, of the postcode database which is accessed principally via the Digital UK website but it is also available via the freeview website and other service providers’ websites. This gives the viewer the opportunity to enter their postcode and to get details about their likely experience, both before, during and after switchover. This has proved to be a very valuable tool, evidenced by the fact that since September 2007, when it first started, there have been something like 22 million hits to the postcode database.

All essential switchover engineering work was completed on time in 2009, despite heavy snowfall across the UK. All essential switchover engineering work was completed on time in 2009, despite heavy snowfall across the UK.

Engineering programme

Last year saw a step change in the engineering programme, led by transmission company Arqiva, with 14 switchovers successfully completed across four TV regions. These included the largest switchover so far at the Winter Hill transmitter and its 70 relays in the north west of England, which together provide television signals to more than three million homes across the Granada TV region.

The engineering work to prepare for switchover is now underway across all remaining TV regions and despite adverse weather conditions towards the end of the year, including extremely heavy snowfall in Scotland, the programme remains on track. This will eventually see upgrades completed at more than 1,150 sites, extending Freeview coverage to 98.5 per cent of UK homes. The increased use of specialist helicopters by Arqiva (see video) has improved efficiency, allowing mast antennas to be replaced in a matter of days rather than weeks, reducing the disruption to viewers.

Specialist helicopters were used during engineering work at the Mendip transmitter in the West TV region. Specialist helicopters were used during engineering work at the Mendip transmitter in the West TV region.

In parallel with the engineering programme, we further developed our online postcode checker to provide information on high-definition TV services, including the newly launched Freeview HD. Viewers can now check the availability of both standard and high-definition TV services in their area both today and after switchover.

'The engineering work to prepare for switchover is now underway across all remaining TV regions.'

Related information