Don.
I see you, have mixed up the compensatingsystem with the fuelsounding. There are three ways of measuring the fuelcontent in the bunkertanks. One for the inboardtanks 1i and 2i which Maciek has explained with his drawings. The pipings,containers,valves and cocks can be seen for 1i at the aft bulkhead in the control room and for 2i at the forward bulkhead, pretty much dominating selector cocks (valves). The samples are drained into rather large containers which used to be removable, today they look like tackwelded into the support and shut by a lid. These containers, which were not marked, and contained fuel, should not be emptied into the bilge but carried and emptied into the measuring container in the engineroom shown on the sketch for the compensating system. After the measuring, the container is drained into the funnel and to the fueloil collector tank. It is hard to see the system on the available photos but I guess you can see the funnels behind some connectionboxes on port and starboard forward engineroom bulkhead.
The saddle fuel/ ballast tanks having checkpipes going almost to the top of the tanks were only checked for compensatingwater at the top and were drained for the F.O.BTKs 2 in the fuel collectingtank in the engineroom and F.O. BTKs 4 in a container in the controlroom.
The third way is that for the F.O. bunker/ regulatingtanks which have sigthglasses next to the sightglasses for the regulatingtanks in the aft end of the controlroom.
Tore