OP
Knobhead
Our LG fabricated Schneider 3.8KA MV Switchboards have insulated tubular bus bars...
It was Laurence Scott Centaur gear I first came across tubular bars as an apprentice. Later English Electric CFS.
The weird ones were Eutrotherm panels, water pumped through to cool the busbars. Water and electrics together sounds dodgy but it worked fine so long as only de-ionised water was used. Depending on the loading the voltage varied between 300 and 1250V, the earth fault trip was set to 40mA.