I was waiting at a local rail station today a0nd spotted these yellow ( presumably metal) discs on the power lines , they are on the last 50m of a dead end siding and was wondering what purpose they serve ?

Any ideas?

They would appear to be around a 300mm or 12 inches in diameter

Ian.

This is the real 3rd picture i intended to post so looking at the pictures in the original post except the bottom one as it is the same as the top one they are taken from right to left.

The first pic is showing the line furthest away far right end , the second is the far right or the closest line and the one in this reply is showing the left end of both lines lines .

The ends of the siding are offset lengthways and if they were both the same the length the discs would approximately line up with each other .

I couldn’t see any other discs on the main lines only on this little dead end siding .

So there are two discs per line equally spaced with each other in regards to each line and its end point .

Forgot to mention this is in the western suburbs of Sydney Australia .

The rail gauge is as far as i know consistent throughout New south Wales Australia .

They are on a now disused siding consisting of two dead end lines about 300m off a set of points , i think they may have used this siding hook up a couple of diesel locos to help the intra state passenger trains or freight trains get over the blue mountains – could and probably am wrong though !