Bilsdale mast fire
 

https://www.bbc.co.uk/news/uk-england-tees-58163612

Shades of Hoogersmilde in Netherlands a few years back ... :o

Guy

Re: Bilsdale mast fire
 

the grainy 2nd picture on the BBC website seems to show smoke coming chimney-like from the top of the mast suggesting the mast itself is burning from within, whereas someone has posted live HD video on youtube showing the conflagration in a surface building some yards away.

Re: Bilsdale mast fire
 

struck by lightning i here, there aree several fire crews there could be off air a while

Re: Bilsdale mast fire
 

Both events at different times? Maybe fire in the building spread to the feeders? That will be a horrible mess for someone to sort out - at least it has happened in summer, and not in the dead of freezing winter.

SWMBO's TV signal comes from Bilsdale although she happens not to be there for the next few days. Looks like we're going to have to dust off the Xbox. :(

Edit: Cross posted with Gallowfields.

Re: Bilsdale mast fire
 

And, of course, Bilsdale is one of the Tubular ones so I wonder if that helps/hinders the firefighting/later repairs?

Re: Bilsdale mast fire
 

Earlier news pictures showed a hut or small building near the mast to be on fire, but later reports such as that linked to above, clearly show fire at several locations on the actual mast.

I wonder what is burning ? I would have expected the mast to be entirely of non combustible materials and that cables therein to be of fire resisting types.

I perceive a real risk of the mast falling, or being weakened to the extent that demolition is required. Steel looses much of its strength in even a minor fire.

Re: Bilsdale mast fire
 

Just watched the local BBC report from tonight's Look North. You can see it on iPlayer if you like - Newcastle version of Look North.

Apparently the mast may now be structurally unsafe. Also, engineering work occurred a few days ago to upgrade mobile phone systems to 5G (mobile services are also currently affected) and there is speculation that this may be the cause.

Looks like it could be weeks before it is working again.

Re: Bilsdale mast fire
 

If the mast falls, or is unsafe for continued use, could services be resumed by mains of a tethered blimp, balloon, or airship ?

Re: Bilsdale mast fire
 

I guess temporary transmissions would probably be from a nearby transmission site whilst something is done at Bilsdale. I guess if the mast had to come down then a temporary mast would be erected similar to what happened at Emley all those years ago (and now!) and a new lattice mast constructed as I would highly doubt another tubular mast would be built knowing their issues.

Re: Bilsdale mast fire
 

Aerial got hit by lightning and the feeder/building caught fire by the DC amps + RF combined once the Zmatch up at the top went awry?

Re: Bilsdale mast fire
 

There do seem to be a lot more of these transmitter mast fires than there used to be. I wonder if incompetent maintenance or upgrade work is going on. The broadcast transmission industry is very different from what it was when Bilsdale was built in 1969.

Oxford (Beckley) had a fire about a decade ago, but the mast survived and service continued, albeit in a degraded state.

Re: Bilsdale mast fire
 

We have a spare mast here, I think the Emley Moor tower is back on air. It was advertised for sale some time ago, but It's a quite limited market!

Re: Bilsdale mast fire
 

The report quotes the fire brigade as saying they attended a fire in a single storey building. Did it have a rather high ceiling, say 300-odd metres?

David

Re: Bilsdale mast fire
 

Some more pictures showing what appears to be fire damage to the mast. The fire must have spread to the feeders, which would burn fiercely in that chimney.
https://www.gazettelive.co.uk/news/t...-mast-21278348

Re: Bilsdale mast fire
 

As a new take on things, what's the chance of the wires inside the mast shorting out resulting in a severe malfunction of the equipment in said building?

Re: Bilsdale mast fire
 

I would hope that the transmitter and feeders would have had some sort of emergency shutdown should there be a significant change detected in VSWR in the aerial systems which could occur if there was a loose connector which started arcing or a feeder cable got damaged in some way.
I would also have hoped that the feeder and other cables would have been specified in the mast design specifications as being self extinguishing and low smoke type to prevent this type of thermal runaway.

Christopher Capener

Re: Bilsdale mast fire
 

Is it coincidence, but there seem to me to be more of this sort of incident since the switch-over from analogue to digital?

Although, if lightning was the cause then the transmission characteristic would not be very relevant. Although not in the same league height wise as Bilsdale, the masts we maintained had very comprehensive lightning protection and even direct strikes were safely dealt with. Feeders were earthed at 20-30m intervals on their way down and at each change of direction. However, where lightning is concerned you should never say never.

Re: Bilsdale mast fire
 

I have looked up VSWR...as someone familiar with acoustic waves propagating with their own characteristic impedance, and what happens in a pipe (say) when they meet some termination impedance which is different to that - I have never understood how an aerial can present a characteristic(-ish) termination to an electrical line. I guess it has to preserve the relationship between v and i experienced by the wave in the line - but I have no idea how its geometry can do that!

(I suspect this might be a bit of a basic question, in which case, sorry! Then again, it's not obvious to start with why a bit of foam can 'look like' a long tube to an acoustic wave)

Re: Bilsdale mast fire
 

The BBC is now reporting that the mast will be off air 'indefinitely'. It certainly won't be sorted any time soon, I guess Arqiva will have to rebuild the entire site.

Meanwhile; might present one or two FM DX possibilities for enthusiasts living in the area?

Re: Bilsdale mast fire
 

Arqiva are likely to install temporary facilities for critical services while the mast is rebuilt, but even that will take a while. It will be interesting to see if they prioritise FM or DAB.

Freesat installers are certainly going to be busy.