[derstosstrupp]

DAILY TRIM DIVE AND ETO REGULATING:

Trimming -
Dive to PD (all dives initiated at GF, ~16 kn) and drop to 1.5 kn (KF), Chief trims the boat at KF. If rough weather, instead trim at anywhere from 20-60 m. The boat was hard to hold at PD over sea states corresponding to winds over 10 m/s. So go deeper to trim at winds 11-15 m/s.

Regulating Etos -
Then to 30-60 m for an hour or two to regulate the Etos. All depth changes at 4.5 kn (HF). Cruise at 3 kn (LF).

When surfacing after running submerged awhile, first to 20 m for sound check at KF, then to PD for scope check. Up scope at just above 20 m on the way up, then SHIFT+F just before it breaks the surface so your chief holds a depth to keep the scope head low in the water. Scan, then down scope, GF (~ 7 kn) to decks awash, scan with UZO. If all clear, surface. Stay on bridge til Chief tells you you are running both diesels and can charge batteries (by then you would also know all tanks have blown). Go below, order charge batteries.

TORPEDO LOADOUT:
(Ato is G7a, Eto is G7e)

VIIA -
All bow tubes loaded with Etos. Bow reserve 2 Atos and 4 Etos. Stern tube an Ato. (Total 8 Etos, 3 Atos)

VIIB and VIIC -
All bow tubes loaded with Etos. Bow reserve 2 Atos and 4 Etos. Stern tube loaded with an Eto. Stern reserve an Ato. Both externals Atos. (Total 9 Etos, 5 Atos)

Why -
Etos required maintenance every few days on various components. Thus they needed to be accessible. The external eels therefore had to be Atos. The two Atos in the bow room were those under the floor plates. These were not immediately accessible due to the two eels sitting atop the floor plates, which were covered by wood boards (yep, bow room was a crowded place). The stern reserve was an Ato too as space for maintenance was insufficient.

Atos also needed maintenance (primarily charging the air tanks), but it was not critical to do so on a schedule as was the case with Etos.

The VIIA aft tube was not accessible and thus needed to be an Ato.