The photo shows the ordinary cable termination of 10 kV, which was overheated due to high currents induced in the screens. We can see traces of excessive heating at the junction of the screen with its grounding wire, caused by significant currents passing there.

The quality of the screen and wire connections is a separate topic (we started this discussion with our group member Dr. Amit Bhatia). But now let’s talk about the magnitude of the screen currents and the heating caused by them. I have several real measurement results, and you can easily repeat them on your 6-35 kV cable lines with the help of 1 kV tongs.

1️⃣ CASE #1. Typical 10 kV line, three 500/95mm2 cables, Cu-core and Cu-screen, laid in a row, the distance between the axes is 250 mm, the line length is 2.5 km (but it does not matter, since the induced current does not depend on the length).
The core current is Ic=185 A.
The screen current is Is=115 A (measured by 1 kV tongs)
The ratio of losses in the screen and core Ps/Pc=2.02.
As one can see, the screen losses are 2.02 times greater than the core losses, i.e. the main source of heating is the screen (not the core)!

2️⃣ CASE #2. Typical 35 kV line, three 630/35mm2 cables, Cu-core and Cu-screen, laid in a row, the distance between the axes is 250 mm, the line length is 1.5 km (but it does not matter, since the induced current does not depend on the length).
The core current is Ic=900 A.
The screen current is Is=235 A (measured by 1 kV tongs).
The ratio of losses in the screen and core Ps/Pc=1.19.
As one can see, the screen losses are 1.19 times greater than the core losses, i.e. the main source of heating is the screen (not the core)!

LOSS ANALYSIS
Total losses in the single-core cable are P=Pc+Ps=Pc*(1+Ps/Pc)
Let the losses in the core be equal Pc=1pu, and then P=(1+Ps/Pc).
In case #1, we get P=1+2.02=3.02, which is 3.02 times greater than Pc=1.
In case #2, we get P=1+1.19=2.19, which is 2.19 times greater than Pc=1.
Thus, the total losses P in the single-core cable are 2-3 times greater than Pc. The main source of cable heating is screens! This means that 6-35 kV cables with two-sides grounded screens work in bad conditions and waste our money for screens heating, and, besides, this heat is against XLPE-insulation.

HOW TO FIX THE PROBLEM?
It can be shown that if these 6-35 kV cables were laid not in a row, but in a closed triangle, then the Ps/Pc ratio would be no more than 0.15-0.25 instead of 1.19-2.02, that is, about 10 times less than when laying in a row.

Thus, in fact, with two-sides screen grounding, laying cables in a row is a bad solution, and the current-carrying capacity in the case of laying in a closed triangle is probably to be higher than when laying in a row. With other types of grounding, the situation will change.