On 10/08/2021 18:25, tony sayer wrote:
> Very much so, be a real sod cleaning that lot out!....

At Eitshal they emptied the transmitter room and a local builder steam
cleaned it I believe.

On 10/08/2021 16:32, MB wrote:
> On 10/08/2021 15:03, Mark Carver wrote:
>> The new DTT antenna caught fire there. Bad enough, but no where near as
>> serious as today's fire at Bilsdale
>
> We don't really know yet whether the building is affected.  Hard to be
> worse than Eitshal where everything was written off, they were not as
> prepared for a complete failure then with just one containerised
> transmitter.
>
Apparently the fire is out, only one building out of four has been
affected and the mast itself, and there are concerns about the
structural integrity of it, so until that's determined, everyone has to
keep 300m away.

On 10/08/2021 18:28, tony sayer wrote:
> Bet it wasn't, that sort of structure will be well earthed and
> protected!..
>
> No reported lightning in the area that I can see of!..

Probably just some "expert" on Twitter but it is not always the classic
"bolt of lightning".

On 10/08/2021 18:09, Jeff Layman wrote:
> What a crap piece of reporting! It just shows the "talking head" whilst
> the action goes on off picture. Why they didn't have the voice going in
> the background whilst the camera focused on the mast fire I don't
> understand.

Isn't that common for that type of "news station", they often seem to
put most effort in devising a very impressive name.

"Mark Carver" <mark.carver@invalid.invalid> wrote in message
news:ing03aF8v3iU1@mid.individual.net...
> On 10/08/2021 16:32, MB wrote:
>> On 10/08/2021 15:03, Mark Carver wrote:
>>> The new DTT antenna caught fire there. Bad enough, but no where near as
>>> serious as today's fire at Bilsdale
>>
>> We don't really know yet whether the building is affected. Hard to be
>> worse than Eitshal where everything was written off, they were not as
>> prepared for a complete failure then with just one containerised
>> transmitter.
>>
> Apparently the fire is out, only one building out of four has been
> affected and the mast itself, and there are concerns about the structural
> integrity of it, so until that's determined, everyone has to keep 300m
> away.

What sort of fire precautions are there at a transmitter site such as
Bilsdale? Do they use Halon or CO2 in the equipment rooms to suppress a
fire, since water sprinkler are not viable because of the electricity?

When I was reckoning how many houses would be affected by the loss of al the
TV signals, I was forgetting about any relays which rebroadcast some of the
off-air signals that Bilsdale transmits. What is the convention with
relays - do they feed relays from the main transmitter where there is good
reception and only to provide an independent feed by cable/fibre where a
relay doesn't have line of sight of the main transmitter?

On 10/08/2021 18:28, tony sayer wrote:
> Bet it wasn't, that sort of structure will be well earthed and
> protected!..

I have known lots of "well earthed and protected" to be damaged (or even
destroyed) by lightning. I spent many hour restoring service at places
after lightning. All had been "well earthed and protected".

Lightning is strange stuff, I went to one hilltop site. Most damage was
the monitoring equipment as usual, the telephone line was dead but OK
after I changed the BT fuse.

We had a metal equipment trolley that was pushed up against the metal
wall heater. The telephone was on the trolley with the handset "coily"
cord trailing over the edge. I pushed the trolley but would not move
until I gave a sharp push - it was spot welded to the metal wall heater.
Then noticed that the "coily" cord was discoloured where it trailed
over the metal edge of the trolley. But it still worked!

On 10/08/2021 19:50, Mark Carver wrote:
> Apparently the fire is out, only one building out of four has been
> affected and the mast itself, and there are concerns about the
> structural integrity of it, so until that's determined, everyone has to
> keep 300m away.

I don't think I would like to be 300 yards away from a collapsing 1000
ft mast!

On Tue 10/08/2021 16:56, Mark Carver wrote:
> On 10/08/2021 16:42, NY wrote:
>> "Mark Carver" <mark.carver@invalid.invalid> wrote in message
>> news:infki3F6j7qU1@mid.individual.net...
>>> On 10/08/2021 16:25, NY wrote:
>>>> "Mark Carver" <mark.carver@invalid.invalid> wrote in message
>>>> news:infe26F59hmU1@mid.individual.net...
>>>>> On 10/08/2021 14:31, Andy Burns wrote:
>>>>>> Mark Carver wrote:
>>>>>>
>>>>>>> Or it could be the building, going by this picture
>>>>>>>
>>>>>>> https://www.thenorthernecho.co.uk/news/19503528.bilsdale-tv-mast-fire-north-york-moors/
>>>>>>>
>>>>>>
>>>>>>
>>>>>> Keep scrolling down ...
>>>>>>
>>>>>>
>>>>> Oh, my. Nothing that can be done there. Stand 1000ft away and watch
>>>>
>>>> Does the second picture, of smoke issuing from the top of the mast,
>>>> necessarily mean that the mast and its cables are on fire? Could it
>>>> be that the hollow mast is acting as a chimney, venting smoke from
>>>> the transmitter building below?
>>>
>>> It'll be very hot smoke, and coating whatever is inside the mast with
>>> all sorts of nasty stuff
>>
>> Do transmitter sites tend to keep the transmitters and the aerials
>> separate so a fire in one doesn't vent hot smoke into the other?
>
> Bilsdale (like Mendip, Belmont, Winter Hill, Waltham, and the ill fated
> Emley mast) are enclosed tubular steel construction.
>
> Quite unstable in certain conditions as two of those masts have had
> collapses (as have similar masts in Germany and The Netherlands)
>
> There's no pictures of the mast base available on mb21, but Waltham's
> arrangement might provide a clue, scroll down
>
> http://tx.mb21.co.uk/gallery/gallerypage.php?txid=679&pageid=164

The tower base is not directly attached to the building so if smoke is
getting up there it is either being piped up the cables of the cables
themselves are on fire. I think the original 6½" aluminium outer cables
would have been replaced ta DSO for smaller all copper co-ax, but if
there is any ally left, well think of Morbourn and the Falklands.....

NY wrote:

> Do transmitter sites tend to keep the transmitters and the aerials
> separate so a fire in one doesn't vent hot smoke into the other?

But aren't the feeders essentially big fat copper tubes?

On 10/08/2021 19:59, NY wrote:
>
>
> When I was reckoning how many houses would be affected by the loss of
> al the TV signals, I was forgetting about any relays which rebroadcast
> some of the off-air signals that Bilsdale transmits. What is the
> convention with relays - do they feed relays from the main transmitter
> where there is good reception and only to provide an independent feed
> by cable/fibre where a relay doesn't have line of sight of the main
> transmitter?

Nearly all relays are fed off air from the parent. There's a few
exceptions since DSO, that are fibre fed because off air reception is
not reliable enough now. Mostly in NW Scotland.

All of Bilsdale's relays are off air fed.

It might be possible, if Bilsdale is going to be off the air (or at
least on very reduced power) for some weeks/months to redirect some of
them to Pontop or Emley.

Similar happened with some of Durris's relays when that station had an
aearil fire in the 80s.  Also all of Peterbourgh's FM relays were
redirected when that mast collapsed in 2004

On Tue 10/08/2021 20:05, MB wrote:
> On 10/08/2021 18:28, tony sayer wrote:
>> Bet it wasn't, that sort of structure will be well earthed and
>> protected!..
>
> I have known lots of "well earthed and protected" to be damaged (or even
> destroyed) by lightning.  I spent many hour restoring service at places
> after lightning.  All had been "well earthed and protected".
>
> Lightning is strange stuff, I went to one hilltop site.  Most damage was
> the monitoring equipment as usual, the telephone line was dead but OK
> after I changed the BT fuse.
>
> We had a metal equipment trolley that was pushed up against the metal
> wall heater. The telephone was on the trolley with the handset "coily"
> cord trailing over the edge. I pushed the trolley but would not move
> until I gave a sharp push - it was spot welded to the metal wall heater.
>  Then noticed that the "coily" cord was discoloured where it trailed
> over the metal edge of the trolley.  But it still worked!
>

I remember an ambulance customer taking a lightning hit on a 30m mast at
the side of the Control building. The mast had a 4ft 1500MHz dish and a
shrouded yagi (a.k.a. donkey's plonker) for analogue links. The
equipment was on the first floor so the cables came off the tower at
about 5m.

The 1500MHz link equipment was untouched, as was the analogue mux
attached to it and the radio control equipment. On the very end was a
PDP11 computer (remember them?) and it took out the 'christmas tree' in
the PDP and fused a four pair telephone cable inside a 2" steel trunk
between the equipment room and the Control Room next door.

On 10/08/2021 19:50, MB wrote:
> On 10/08/2021 18:25, tony sayer wrote:
>> Very much so, be a real sod cleaning that lot out!....
>
> At Eitshal they emptied the transmitter room and a local builder steam
> cleaned it I believe.
>
Could be fun doing that inside a 1000 ft long, 6 ft diameter metal tube !

On Tue 10/08/2021 20:10, MB wrote:
> On 10/08/2021 19:50, Mark Carver wrote:
>> Apparently the fire is out, only one building out of four has been
>> affected and the mast itself, and there are concerns about the
>> structural integrity of it, so until that's determined, everyone has to
>> keep 300m away.
>
> I don't think I would like to be 300 yards away from a collapsing 1000
> ft mast!

You would be safe enough. The tower would not come down like some mill
chimneys but would start to break up into sections that would fall on
top of each other.
Plus the tube probably only extends to about 800ft (if WH is an example)
and the aerial structure is a lattice so would all fall on itself.

Dig into Google and have a look at the pictures after EM collapsed and
you'll see what I mean.

Am 10.08.2021 um 17:56 schrieb Mark Carver:

> Bilsdale (like Mendip, Belmont, Winter Hill, Waltham, and the ill fated
> Emley mast) are enclosed tubular steel construction.
>
> Quite unstable in certain conditions as two of those masts have had
> collapses (as have similar masts in Germany and The Netherlands)

On 15 January 1985, the tubular steel tower "Bielstein (Teutoburger
Wald)" of WDR in Germany collapsed in the early morning hours. The tower
was 298 metres tall; there was no fire, but it collapsed due to high
winds and icing of the guy wires. At that time I was a student in
Münster and got my wake-up call from the radio. On that morning the the
radio suddenly went silent before half past six. I switched to another
frequency, only to learn of the reasons for the transmitter failure in
the news bulletin at 7. The background is described here:
https://www1.wdr.de/sendemastpdf100.pdf (page 13-, in German, but with
plenty of pictures).

Notably, the main FM service on 93.2 MHz was back on air 8 hours later,
using a backup transmitter of BFBS in Bielefeld, some 30 km northwest of
Bielstein. It took a few more days for the WDR engineers to install a
backup tower at Bielstein and more than a year to replace the original
tower with a steel lattice construction of 302 metres.

By the way, BFBS has stopped broadcasting from Bielefeld only in spring
2020, after most of the British troops had left the area.

Regards,
Uli

On 10/08/2021 18:28, tony sayer wrote:
snip
> No reported lightning in the area that I can see of!..
>

Unless I'm misusing it, or as its Beta it's not working there is no
Lightning shown in the area on Lightningmaps.org!

http://www.lightningmaps.org/?lang=en#m=oss;t=3;s=0;o=0;b=0.00;ts=0;y=54.3591;x=-1.1464;z=15;d=2;dl=2;dc=0;tsc=1;ts24=1;ar;as=21-08-10T06;

On 10/08/2021 20:10, MB wrote:
> On 10/08/2021 19:50, Mark Carver wrote:
>> Apparently the fire is out, only one building out of four has been
>> affected and the mast itself, and there are concerns about the
>> structural integrity of it, so until that's determined, everyone has to
>> keep 300m away.
>
> I don't think I would like to be 300 yards away from a collapsing 1000
> ft mast!

Yes but factor in your running speed and you're probably just OK.

Bill

On 10/08/2021 20:24, Mark Carver wrote:

> It might be possible, if Bilsdale is going to be off the air (or at
> least on very reduced power) for some weeks/months to redirect some of
> them to Pontop or Emley.

Why not simply equip them with freesat dishes?

Bill

On 10/08/2021 20:28, Mark Carver wrote:
>>
>> At Eitshal they emptied the transmitter room and a local builder steam
>> cleaned it I believe.
>>
> Could be fun doing that inside a 1000 ft long, 6 ft diameter metal tube !

Especially as it's vertical.

Bill

On 10/08/2021 20:30, Woody wrote:
> On Tue 10/08/2021 20:10, MB wrote:
>> On 10/08/2021 19:50, Mark Carver wrote:
>>> Apparently the fire is out, only one building out of four has been
>>> affected and the mast itself, and there are concerns about the
>>> structural integrity of it, so until that's determined, everyone has to
>>> keep 300m away.
>>
>> I don't think I would like to be 300 yards away from a collapsing
>> 1000 ft mast!
>
> You would be safe enough. The tower would not come down like some mill
> chimneys but would start to break up into sections that would fall on
> top of each other.
> Plus the tube probably only extends to about 800ft (if WH is an
> example) and the aerial structure is a lattice so would all fall on
> itself.
>
What about the guy ropes though, would they 'whip' beyond the mast's
fall zone ?

The local paper news page has more photos, the last two don't look good,
(or maybe its just superficial damage ?)

https://www.examinerlive.co.uk/news/local-news/gallery/tv-channels-north-yorkshire-overnight-21279584

On 11/08/2021 02:33, williamwright wrote:
> On 10/08/2021 20:24, Mark Carver wrote:
>
>> It might be possible, if Bilsdale is going to be off the air (or at
>> least on very reduced power) for some weeks/months to redirect some
>> of them to Pontop or Emley.
>
> Why not simply equip them with freesat dishes?
>
Freesat would be no good, but the 27.5W back up satellite carrying
pre-assembled transport streams would be.
Except it's designed for back up of the main stations, (should they lose
their fibre feeds) not 'dumb terminal' relays

On 11/08/2021 02:33, williamwright wrote:
> Why not simply equip them with freesat dishes?

How many thousand Freesat dishes can you install per day?

They have managed to restore services fairly quickly on previous
occasions and now better equipped with emergency transmitters, masts etc.

On 11/08/2021 07:35, Mark Carver wrote:
> What about the guy ropes though, would they 'whip' beyond the mast's
> fall zone ?

I was wondering about that yesterday, they are probably the biggest danger.

On 11/08/2021 07:40, Mark Carver wrote:
> On 11/08/2021 02:33, williamwright wrote:
>> On 10/08/2021 20:24, Mark Carver wrote:
>>
>>> It might be possible, if Bilsdale is going to be off the air (or at
>>> least on very reduced power) for some weeks/months to redirect some
>>> of them to Pontop or Emley.
>>
>> Why not simply equip them with freesat dishes?
>>
> Freesat would be no good, but the 27.5W back up satellite carrying
> pre-assembled transport streams would be.
> Except it's designed for back up of the main stations, (should they lose
> their fibre feeds) not 'dumb terminal' relays

Yes, the 11.495 GHz transponder at Intelsat 901 at 27.5W....

https://www.lyngsat.com/Intelsat-901.html

On 11/08/2021 08:49, MB wrote:
> On 11/08/2021 02:33, williamwright wrote:
>> Why not simply equip them with freesat dishes?
>
> How many thousand Freesat dishes can you install per day?
>
> They have managed to restore services fairly quickly on previous
> occasions and now better equipped with emergency transmitters, masts etc.
>
>
I gather Arqiva have a containerised Tx set and a mast on the way there.
I doubt it's a 1000 footer mast though, so I wonder how much signal will
actually get to the primary urban target area ?

My bet on getting the local FM stations back, is to use Eston Nab

http://tx.mb21.co.uk/gallery/gallerypage.php?txid=759

Well it was on the news last night but few details other than an exclusion
zone in case of compromised structural integrity.
Brian

--

This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...
briang1@blueyonder.co.uk
Blind user, so no pictures please
Note this Signature is meaningless.!
"Andy Burns" <usenet@andyburns.uk> wrote in message
news:infc72F4saeU1@mid.individual.net...
> Mark Carver wrote:
>
>> Reports that there is a fire there ?
>
> <https://twitter.com/NorthYorksFire/status/1425081443001188364>