"Sound" research for my scale Bismarck

[Aktungbby]

ANOTHER INTERESTING PASSAGE: INVOLVING THE MINISUB ATTACK ON TIRPITZ IN THE FJORD:

On board Tirpitz the day had begun much as usual. At 0500 the hydrophone listening watch had been secured and maintenance on the sets had been started when at 0707 an object was briefly sighted but mistaken for a porpoise and disregarded: it was X-6 running aground inside the A/T net. At 0712 X-6 was correctly identified when she again broke surface some 68 meter (75 yards) off the port beam (a note in Tirpitz's log states that times between 0710 and 0730 are inaccurate) and the power boat was manned at the gangway. At the same time the alarm was raised throughout the battleship by the alarm bell.

A certain amount of confusion seems to have arisen here by the misuse of the alarm bell. Instead of the correct number of rings for "submarine danger" the bell was rung for "'close water-tight doors", so that the actual threat to Tirpitz was unknown to most of her ship's company. The anti-aircraft armament was manned but X-6 was too close to the battleship and her attendant craft to allow them to open fire

I cannot imagine that Bismark's sistership would have different bell system alarms. On the occasion of the Airraid that capsized the Tirpitz:

At 8.30 on the morning of 12 November 1944, the gun crews and lookouts on the decks of the battleship Tirpitz stood at their action stations staring intently into the eastern sky. It was a crisp, clear day. The sunlight sparkled on the waters of the Norwegian fjord where they lay anchored in a bowl of snow-smudged hills. A few minutes before there had been a clamour of bells and blaring loudspeakers as an air raid warning was announced.

The bells might be similar to D-day german bunker two-gong alarm bells: shown twice early in the propaganda film but I can't make out the manufacture name on the upper element...