posted on Jul, 1 2008 @ 10:42 AM
Are there high voltage power lines traversing the area?
Usually on towers and voltages can run from 66kv (1kv = 1000 volts) to 1000kv.
The 1000kv lines in the US are DC and AC lines run from 66kv as noted up to about 745kv.
I would guess that high voltage transmission lines in Wales would be about 230kv and lower.
These lines have protection equipment that will trip them off due to faults in a very short time when everything works as it should . . . which is
most of the time.
Very short time defined as 7 HZ or less for the higher voltage stuff and up to two full seconds (120 HZ) for 66kv level equipment.
Occasionally - actually very seldom - the higher voltage lines won’t trip as fast as they should and if a conductor goes down it will melt blobs of
glass out of sandy areas.
You’ll also find blobs of aluminum that look similar to what was shown in the photos.
The aluminum blobs come from the high voltage conductors which are aluminum strands wrapped around a steel core which adds strength so as to support
the weight of long spans of conductor.
Much the same happens with lower voltage distribution lines.
Many times melted glass blobs will be found underneath where the conductor was laying and there can be quite a bit of it.
Distribution level lines (4kv to 16kv depending on what part of the country you’re in and I would guess European distribution levels are much the
same) can take a while to trip due to their protection schemes which are less exotic and considerably slower than are the transmission line protection
What you can find with a distribution level line down and remaining energized for a while is a lot of glass, but most times what you’ll find with
aluminum conductors at that voltage level is a lot of short pieces of stranded aluminum conductor that were blown apart on the initial fault (short
These strands are characteristically ½" - 4" or so long.
Under the right conditions these downed distribution level lines can remain energized until a line crew gets out there, makes recommendations to the
power station to open the circuit breaker until they can cut the faulted conductor clear and the remainder of the line can then return to service.
You can find melted blobs of aluminum near distribution lines that have gone down, but they are more common to transmission lines.
Copper conductors react similarly, but today, not many copper conductor lines remain in service in the US and those that do are usually found at the
2.4kv to 4kv voltage levels.
More than likely the same would be true for Europe.
As to the comment about it being a bit heavy for aluminum, most folks are used to handling thin aluminum sheet metal and have perhaps never handled a
small billet of aluminum which is heavier than most think.
As I was reminded of yesterday when I pulled a plastic milk crate about half full of aluminum billet square, rectangular and round stock up to about
6" across and a foot or so long.
The crate is almost more than I want to pick up off the floor so that’s why it’s half full and not too tightly packed.
And . . . as usual, no 3" diameter round so I had to machine a 4" piece down to fit.
I hate to waste materials, but sometimes there’s no choice.
Just for fun I weighed a small round billet of 2 ½" diameter, 10 ½" long piece of 6061 T6 (very common alloy in the US) and the weight came in a
couple of ounces under 5#.
So there’s one explanation if there are transmission or distribution level lines in the area.
If not, then we need to submit a sample to an appropriate testing agency for analyzation, but I’m betting it’s simply a melted piece of aluminum
with some impurities from the soil it was found in.