I contracted to a company in 2008 working in the basements of parliment. What I can say is the floors are meticulousy clean, dedicated pipe racks doned the walls to individually hold the pipes. In areas with not alot of space service cables data telephone cables and fire were bunched indvidualy. In no way would I have said it was damp down there and far better than many of the places I have worked.
The bit where it said the “pipes go nowhere” is actually a manifold and several dotted about down there and of course the pipes go somewhere, branching out into smaller pipes to prove heating and ventalation to the rooms above!
There are some high walls doned with holes that have glass “hats” ontop, that use to provide ventilaton in the victorian times, along with other unusual fixtures.