Orange balls on power lines, again
- Campo Steve
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Orange balls on power lines, again
This was discussed about 4 years ago but no definitive answer was agreed upon. I wonder if a real answer is now available.
Where power lines cross motorways in Spain they have orange balls attached to them. Why?
One common suggestion was to warn aircraft and helicopters of the existence of the power lines. I don't go along with that as when an aircraft or helicopter is following a line feature it should keep that feature on its left to avoid collision with opposite direction aircraft. Yet the balls are only on the cables actually over the motorway so don't satisfy that requirement.
Another suggestion is to prevent birds flying into them. What is the point when there are no balls on cables not over motorways and the balls are only on one cable, even when there are clusters of cables crossing. Can't see that working.
Another suggestion I have heard is they stop the cables swinging in high wind. Again, why only over motorways.
One suggestion that could be possible is to highlight the cables to high vehicles or inspectorsin the summer when cables expand and sag.
What is the real reason for these balls on the cables?
Where power lines cross motorways in Spain they have orange balls attached to them. Why?
One common suggestion was to warn aircraft and helicopters of the existence of the power lines. I don't go along with that as when an aircraft or helicopter is following a line feature it should keep that feature on its left to avoid collision with opposite direction aircraft. Yet the balls are only on the cables actually over the motorway so don't satisfy that requirement.
Another suggestion is to prevent birds flying into them. What is the point when there are no balls on cables not over motorways and the balls are only on one cable, even when there are clusters of cables crossing. Can't see that working.
Another suggestion I have heard is they stop the cables swinging in high wind. Again, why only over motorways.
One suggestion that could be possible is to highlight the cables to high vehicles or inspectorsin the summer when cables expand and sag.
What is the real reason for these balls on the cables?
I've got an inferiority complex, but it's not a very good one!
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Re: Orange balls on power lines, again
Your are right with your first theory. They are there for the benefit of helicopters carrying out traffic analysis and surveys. Something that started some time ago for traffic reports on local radio. You don't see them in the UK because power cables are rarely more than 15m above a highway. In continental Europe they can be up to 100m above the highway.
If they were for any other reason i.e. wind etc., why is it it only the highest set of wires that have the markers!
If they were for any other reason i.e. wind etc., why is it it only the highest set of wires that have the markers!
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Re: Orange balls on power lines, again
A quick Google search brings up lots of info. The consensus seems to be that they are an aid for low flying aircraft because it is not easy to see cables when looking down at them against the background of land. They are also found in the UK but not always coloured orange, white being the normal colour there.
- Campo Steve
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Re: Orange balls on power lines, again
So far I am not convinced. If they are there to help aircraft spot the cables, why are they only situated directly over the motorways? Light aircraft and helicopters fly elsewhere than directly over motorways.
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Re: Orange balls on power lines, again
Possibly because they may need to land a helicopter on the motorway in the event of an accident etc.
Sid
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Re: Orange balls on power lines, again
I actually asked a Spanish campo dweller near our place this very question some years back...........he had been a cable layer in Madrid and all over Spain and earned good money enabling him to retire early to the campo and buy a large swage of land. Albeit my grip of the language at the time was errrr sparse!!
However OH and I de-ciphered his answer to mean the orange balls are in fact insulators, and act as such if they were to come down on a Motorway and fall on a coach,lorry, cars etc, i.e. keeping cable off vehicles so they won't become wired in series ...........it also makes them easier/safer to remove in such an event.
I'll ask again by phone in the next day or two to see if I understood right............and get a definitive answer if not.
However OH and I de-ciphered his answer to mean the orange balls are in fact insulators, and act as such if they were to come down on a Motorway and fall on a coach,lorry, cars etc, i.e. keeping cable off vehicles so they won't become wired in series ...........it also makes them easier/safer to remove in such an event.
I'll ask again by phone in the next day or two to see if I understood right............and get a definitive answer if not.
Property owner in Andalucia since 2002. How time flies.
- Campo Steve
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Re: Orange balls on power lines, again
Thanks DA. I did wonder if that was a possibility but when there are four cables crossing the motorway from the same pylon, only one has the balls fitted. Just have to hope it is that cable that falls.
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Re: Orange balls on power lines, again
Hi Steve, as I say that's what we "thought" he meant. I personally did and to some extent still do reckon it's as a sighter for rescue heli's.
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Re: Orange balls on power lines, again
Think about the logic behind this answer; the cables are flexible and there may be only 4 or 5 indicators over the width of a six lane carriageway. The indicators are on the highest wires only, there may be three or four levels of high tension cables crossing the road. The balls are about 300mm in diameter. Most high tension cables carry 110 Kv and are about 40mm in diameter.Devils Advocate wrote:to mean the orange balls are in fact insulators, and act as such if they were to come down on a Motorway and fall on a coach,lorry, cars etc, i.e. keeping cable off vehicles so they won't become wired in series ...........it also makes them easier/safer to remove in such an event.
So if the highway is 35m wide and there are five indicators the distance between each indicator is approximately 8m so the indicator is supposed to keep a 40mm loose cable [remember the cable has fallen so is no longer in tension] clear of the ground over this length.
No, it just cannot happen. They are for visual indication of the highest cable from the air over a highway. I think Sid is right with regard to helicopters landing in emergencies but also traffic reports use low flying aircraft and also highway inspection often utilise aircraft.
Re: Orange balls on power lines, again
Looking in a few Spanish sites, someone says that these "esferas de señalización" are for that purpose, ie to advise helicopters of high tension cables. According to him they are placed at other places, such as hospitals etc. places where a helicopter may land. Another forum gives some very technical info which is quite different, so that the cables can't touch each other, they help reduce vibration etc, so who knows, maybe a bit of both.El Cid wrote:Possibly because they may need to land a helicopter on the motorway in the event of an accident etc.
Sid
Regards, Frank
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No soy residente, simplemente un turista, ¿qué sé yo?
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Re: Orange balls on power lines, again
As has already been suggested, they are an aid to visibility for aircraft operating in the are; this could be crop dusting, airfield activity or an evac area for helicopters including military aircraft. Whilst the OP is correct regarding line features, you don't physically follow every curve of the motorway so its easy to lose sight of power lines.
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Re: Orange balls on power lines, again
What makes me dubious about that is that the balls are only directly over the motorways. Modst aircraft operate outwith that area.Faire d'Income wrote:As has already been suggested, they are an aid to visibility for aircraft operating in the are; this could be crop dusting, airfield activity or an evac area for helicopters including military aircraft. Whilst the OP is correct regarding line features, you don't physically follow every curve of the motorway so its easy to lose sight of power lines.
I've got an inferiority complex, but it's not a very good one!
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Re: Orange balls on power lines, again
Steve, GA/Mil operate frequently in that area; I certainly use motorways as line features to aid navigation. What you may not appreciate is that visibility (slant vision) etc is significantly depleted at altitude and what appears to be a typical summer's day on the ground where you can see for miles is reduced at height. Even in the UK, with CAVOK I'd argue the visibility is better than in Spain due to its approximation to the Sahara and other environmental impacts; its not always that easy to see conflicting traffic such as balloons!Campo Steve wrote:What makes me dubious about that is that the balls are only directly over the motorways. Modst aircraft operate outwith that area.Faire d'Income wrote:As has already been suggested, they are an aid to visibility for aircraft operating in the are; this could be crop dusting, airfield activity or an evac area for helicopters including military aircraft. Whilst the OP is correct regarding line features, you don't physically follow every curve of the motorway so its easy to lose sight of power lines.
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