Hi there, Yes STx ... Fibreglass almost certainly, cant be metal going thru the loading coil
as would give a shorted turn like secondary, tube Diameter in and out of Coil is the same
The black blobs, like the one under the coil, look like a telescopic fibreglass locking points

The Box is a mystery, why, if it is an ATU, is the removeable cover, facing Away from the walkway
and Why has it got, what looks like a camera, mounted on the Cover
If it is the ATU, you would have thought, cover would be facing Walkway for adjustments

The wire coming out the base of the tube, is black, same as above loading coil colour
you can see the lower clamp has got a yellow earth? wire, also another yellow wire near
both these wires go downwards, below the walkway floor rings, not upwards towards the box

Hi Confused... A loading coil can be put anywhere, at the top, between the Capacity hat and pole
is better electrically, but having the extra weight right at the top, worse mechanically, can fail etc

The reverse is, coil at the base, at the feed point, worse electrically, better mechanically
so half way up a compromise etc... The idea of Coil being spread out, over most of the length
like the Valcon one that failed on the Ross, is just a variation on a theme
It failed because was not intended to stand that high power, and made for land use, not on a ship

Rod Watts