Was the battleship Bismarck really the best of its time?

[José M. Rico]

to 2) I took this from the book "Battleship Bismarck- A Design and Operational History of William H.Garzke Jr., Robert O. Dulin Jr., and William Jurens (moderator of this forum), with James Cameron, page 43.
There it says: "The conning tower roof plates were 220mm of KC armor, the sides were 350mmm, ...Cylindrical KC armor of 220-mm thickness shielded the communications tube joining this key position with battle stations below the armored deck."
I do not possess primary sources. But I have faith in the honesty and influence of Mr Jurens regarding this book.

Definitely wrong. Diregarding the sides it's all Wh. Roof plate is 200mm.

The 220 mm figure for the roof appears in the "Bismarck Warship Profile 18" by Paul Schmalenbach and also in some publications By Siegfried Breyer.
I believe it is a typo since I have not found any other source either primary or secondary that provides that data. Gröner and Brennecke (who used Gröner as a source) give 200 mm for the roof which is in accordance with original drawings.
I have now to correct that data on the website protection page!

[hans zurbriggen]

Hello,
in addition to Mr. Saxton post that I referenced already (viewtopic.php?p=43770#p43770), I have found another interesting post from Mr. Saxton confirming Bismarck had FuMO 27 (FuMG 40G) and not FuMO 23 (FuMG 39G), at least by May 1941: viewtopic.php?p=39136#p39136

and a second one for Tirpitz (stating that she never had FuMo 23): viewtopic.php?p=52378#p52378

hans

[Herr Nilsson]

The crucial question is: What's the difference between FuMO 23 and 27 at all?

• 2000 Hz vs 500 Hz?
• No "Feinpeil" vs "Feinpeil"?
• TS1 tube vs TS9 tube?

[Thorsten Wahl]

TS4 ?

[Herr Nilsson]

TS1 tube vs TS9 tube?

It should read
TS 1 tube vs TS 6 tube.

[hans zurbriggen]

Mr. Nilsson wrote: "What's the difference between FuMO 23 and 27 at all?"

According to Mr. Saxton (see links in above posts):
"FuMO23: output (power) = 2kw, and PRF (Pulse Repetition Frequency) = 2000hz
FuMO27: output =8kw (min), and PRF =500. (typical BB to BB range of 30,000 meters +/- 50 meters)"

Output power difference would obviously allow larger effective maximum range to FuMO27, while lower PRF would allow larger measurable distances span'. Also, I remember that TS6 should have been more resistant to shocks than previous tubes. AFAIK antennas were similar for both models.

What about Feinpeil ? If I understand correctly what Mr. Wahl said, this was a 'module' that could be added to a radar.

hans

[Herr Nilsson]

Hello Mr. Nilsson,

you write: 'The first series is unit 1-31. That should be FuMG 39G (in case of Bismarck FuMO 23). It is almost confirmed Bismarck got unit 11 and 17 (the third one remains unclear).
The first technical change was made in unit 32 and following (FuMG 40G?= FuMO 27). The whereabouts of the second series until the sinking of Bismarck is well documented. A FuMO 27 is at least debatable or even implausible'.

Which model of radar was on board of Prinz Eugen in May 1941, according to your sources ?

hans

In Dezember 1941 Prinz Eugen still had unit No. 10 TS6 and 15 TS1. Both had an impulse frequency of 2000 Hz.
At the same time Tirpitz had one 2000 Hz-unit (No. 30 TS1) and two 500 Hz-units (No. 61 TS6 (replacement! of No 18.) and 69 TS1).
It looks like Scharnhorst got Gneisenau's unit No. 2 TS6 in addition to her No. 1 TS6 (both 2000 Hz). However, No. 48 (500 Hz) was provided for Scharnorst, but seemingly not installed in Dezember 1941.
Gneisenau got two brand-new 500 Hz-units (No. 80 TS6 and 81 TS1).
While some older units were modified from TS 1 to TS6 apparently all units up to No. 31 kept their 2000 Hz inpulse-frequency (at least until Dezember 1941), therefore it's very unlikely Bismarck had any 500 Hz-FuMO.

In regard of "Feinpeil": As it seems only the foretop FuMO had this capability.

[hans zurbriggen]

Hello Mr. Nilsson,
thanks for these info.
However, what about Mr.Saxton (viewtopic.php?p=43770#p43770) saying that Bismarck radars (plural) were tested and recorded as having 9Kw power output and ~500 hz pulse repetition rates ? These figures (especially power output) are for a FuMO27 with TS6.

hans

[Herr Nilsson]

Ask Dave.

[hans zurbriggen]

Done already (see my post from July 14 at 08:54), I hope Mr.Saxton still read this forum.
hans

[Thorsten Wahl]

@Marc whats your source on the allotment details of "Funkmess" equipment

[Herr Nilsson]

Try PG33572. It contains most of the allotment from 1939 to 1941. However, there are several snipets in other Rolls.

TS4 ?

AFAIK TS4 was meter wave and used for Flum. TS1 and TS6 were decimeter wave.

[Thorsten Wahl]

My fault had to look in the fumg manual

[fsimon]

May I try to summarize, what I understood of the radar fire control of the main contenders. Please correct me!

1941 capabilities:

Bismarck 3 x Seetakt FuMO 27

Range vs BB 30km
Range accuracy @ 20km: 36-40m (range independant)
Bearing accuracy: 0.1° ("Feinpeilung")
Range resolution: 100m
Bearing resolution: 3°
And thus able to spot for fall of shots.
Data automatically and continuously integrated into fire control.
Redundant centralized remote power control (RPC) in azimuth and elevation of main and secondary gun batteries.

Prince of Wales 1 x Type 284

Range vs BB 24km
Range accuracy @ 20km: 109m
Bearing accuracy: 0.75°
Range resolution: 300m
Bearing resolution: 3°
Only able to spot for fall of shots out to 12.5km.
Data fed into fire control manually.
No RPC, follow the pointer (FtP) instead.

[fsimon]

1942 capabilities:

Tirpitz 3 x Seetakt FuMO 27

Range vs BB 30km
Range accuracy @ 20km: 36-40m (range independant)
Bearing accuracy: 0.1°
Range resolution: 100m
Bearing resolution: 3°
And thus able to spot for fall of shots.
Data automatically and continuously integrated into fire control.
Redundant centralized remote power control (RPC) in azimuth and elevation of main and secondary gun batteries.

Duke of York 1 x Type 284M

Range vs BB 26.5km
Range accuracy @ 20km: 109m
Bearing accuracy: 0.08° lobe switching introduced
Range resolution: 150m
Bearing resolution: 4.5°when switching
Only able to spot for fall of shots out to 14.6km.
Data fed into fire control manually.
No RPC, follow the pointer (FtP) instead.

North Carolina 1 x Mk3

Range vs BB 25.6km
Range accuracy @ 20km: 57m (range dependant)
Bearing accuracy: 0.1°
Range resolution: 370m
Bearing resolution: 15° when lobeswitching
And thus not able to spot for fall of shots due to bad resolution.
Data automatically and continuously integrated into fire control.
Centralized remote power control (RPC) for main battery.