Just seen a post on about trunking 'rammed'.
Found this from 2015...an old mill split into units.
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The office building I worked in at a previous job was "interesting". Wish I had some pictures.
Multiple units (IIRC about 40 in the main building), central incomer and meter room - two incomers, each feeding a 3ph, 10 DNO way fuseboard, and walls filled with switch-fuses and meters (and a lot of teleswitches), everything 1ph in this part of the site.
Many of the downstairs units were supplied by MICC. All I can say is I bet that was fun to work with, from memory somewhere between 1/2" and 1" thick - I imagine someone can probably suggest what size it was, assume 63A cartridge fuse at the supply end, and varying from 20 to 50m runs. And "a load" of them stuffed into trunking.
Now, they ran trunking down the corridor once past the central "square" (which had a false ceiling). 6x2, 3 section, one section for the power supplies - and no, some of the lidding didn't fit properly when it was newly built, even well dressed (which they weren't) it would have been a struggle to get that much MICC in a 2x2 section of trunking.
The next fun thing was that you'd look at it, it ran along the corridor until it reached the wall, and on the other side of the wall there was a ceiling void. "That's handy" you might think when asked to pull some network cables in ... until you look and the trunking stops dead against some structural steelwork. If you suggest I had some uncomplimentary thoughts about the architect then you would be right.
And of course, most people who had to go into the trunking c.b.a. to refit the lids properly.