Was the battleship Bismarck really the best of its time?

[Herr Nilsson]

Prinz Eugen got radar sets from the first series (No. 10 foretop and No. 15 aft).

[Thorsten Wahl]

understanding questions
regarding fuel consumption of Tirpitz.

the data point for 31,7 kn lists a consumption per hour from about ~68 m³ of fuel oil per hour.

but based on the the data from the Saacke burners (two per boiler)
they are listed with fuel consumption of 3950 kgs /per hour per unit at "Äußerster Last", wich is about 3,750 m³ (density 0,95 t/m³)per hour per unit

that means 24 X 3,750 m³ ~ 90 m³ max consumption. This is much more then the 68 m³ figure.

Am I miss something ?

the line for max range gives ~7500 sm range at about 17 kn
if one compares that with the "korrigierte Tabelle über den Fahrbereich" from Oberbaurat Krux(1944) its surprisingly low.
even with the worst case oil as calculation basis (~8800 kcal/l) he lists the range at 17 kn with 9000 sm.

Based on the datapoint ~28,5 kn, fuel rate ~50m³ per hour, range ~3150 sm
it follows that they are using ~5500 m³ fuelcapacity for this comparision

[Thorsten Wahl]

.

Which model of radar was on board of Prinz Eugen in May 1941

these unit(s) consist of a Feinpeileinrichtung and a Aufschlagmessgerät (=Entfernung fein=Messkette) according to a fragmentary piece from a E.mess protocol.

Scharnhorst and Gneisenau used Messkette units during winter 1940/41 and experienced overreach over the visible horizont. The equipment was improved to get measurements under such conditions (i.e. changing pulse repetition frequency)

[dunmunro]

understanding questions
regarding fuel consumption of Tirpitz.

the data point for 31,7 kn lists a consumption per hour from about ~68 m³ of fuel oil per hour.

but based on the the data from the Saacke burners (two per boiler)
they are listed with fuel consumption of 3950 kgs /per hour per unit at "Äußerster Last", wich is about 3,750 m³ (density 0,95 t/m³)per hour per unit

that means 24 X 3,750 m³ ~ 90 m³ max consumption. This is much more then the 68 m³ figure.

Am I miss something ?

the line for max range gives ~7500 sm range at about 17 kn
if one compares that with the "korrigierte Tabelle über den Fahrbereich" from Oberbaurat Krux(1944) its surprisingly low.
even with the worst case oil as calculation basis (~8800 kcal/l) he lists the range at 17 kn with 9000 sm.

Based on the datapoint ~28,5 kn, fuel rate ~50m³ per hour, range ~3150 sm
it follows that they are using ~5500 m³ fuelcapacity for this comparision

We discussed this 12 years ago:

Re: Oil Burners fitted on Bismarck
Post by dunmunro » Sun Jun 13, 2010 1:01 am

Herr Nilsson wrote:
I understand. I'm sorry, I don't know the exact type, but there are some data about the burner:

nominal 1,8 t/h fuel
max 2,13 t/h
min 0,35 t/h
nominal air flow 3000 cbm/h
nominal rpm 6000

Max fuel flow = 2 x 2.13 t/h x 12 = 51.12 t/h. Max mSHP, assuming that the specific consumption of .325 gm/hp/hr ( http://www.bismarck-class.dk/technicall ... inery.html ) remains constant = 157292. In fact the specific consumption appears to be rising, and at .34 gm/hp/hr the max SHP would be ~150350.

[hans zurbriggen]

Hello all,
weren't 'Saacke' burners of same model on both Bismarcks (Bismarck and Tirpitz) ?

hans

[Thorsten Wahl]

ut based on the the data from the Saacke burners (two per boiler)
they are listed with fuel consumption of 3950 kgs /per hour per unit at "Äußerster Last", wich is about 3,750 m³ (density 0,95 t/m³)per hour per unit

I made a mistake here

the fuel Consumption at äußerste Last was for boilers (including two Saackes) and was listed with 3950 kgs/per hour

[dunmunro]

ut based on the the data from the Saacke burners (two per boiler)
they are listed with fuel consumption of 3950 kgs /per hour per unit at "Äußerster Last", wich is about 3,750 m³ (density 0,95 t/m³)per hour per unit

I made a mistake here

the fuel Consumption at äußerste Last was for boilers (including two Saackes) and was listed with 3950 kgs/per hour

Thanks. So that places a hard upper limit on Bismarck and Tirpitz's power output as ~150-157K SHP.

[Herr Nilsson]

Bismarck and Tirpitz were different. Bismarck's specific consumption was rising again beyond a certain WPS-rate, but Tirpitz' specific consumption (as a function of WPS) was always decreasing.

[wadinga]

Hi All,

Bismarck and Tirpitz were different.

Indeed they were and if your tyre pressures are low or you leave your roof rack on,your consumption will be different to published figures for your car model (which are merely a guide).

As soon as a ship's boilers and condensers are fired up they start to have different heat transfer characteristics which vary consumption to horsepower ratios. An article at https://binsfeld.com/the-ultimate-guide ... on-meters/ explains how 21st century marine shaft horsepower is measured from shaft torsion to a claimed accuracy of 3 to 5%.

No matter what the horsepower delivered to the shaft and hence propeller, because of a host of factors already described there is no direct, immutable or repeatable relationship between shp and and actual vessel speed. Ship's engineers leave a margin of safety to cover these variabilities.

What a ship's complex installation can deliver six months, a year, five years or twenty after her trials performance, is not subject to a builder's guarantee. Repairs to Hood's turbines do not affect the performance of boilers and condensers.

Since marine fuel oil also varies in quality in terms of Megajoules per kg, especially with the strictures of wartime, even the amount of energy input is variable.

The maximum speed a ship can deliver on the day, under prevailing conditions, is what it is. Graphs are guides only. Extrapolated graphs are guesswork/wishful thinking.

All the best

wadinga

[hans zurbriggen]

Hello Mr. Nilsson,

you wrote: '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.'

I understand FuMG 40G was available from second half 1940. It's very strange that German flagship sailed for her mission with an 'old' model when 'new' one was available since so much time.
Is it possible that FuMG 40G replaced FuMG 39G (unit 11 and 17) when the last radar (fore position) was fitted (April 1941) or even after (just before her departure) ?

What about Tirpitz: was she equipped with FuMG 40G since beginning ?

hans

[Thorsten Wahl]

Seetakts were modular systems.
"Feinpeil Modul" and "Entfernung fein Modul" were easy to integrate -if not installed-; these modules(Zusatzgerät) characterize the firecontrol "Seetakt".

Gneisenau / Scharnhorst and Prinz Eugen definately had both modules.
and Bismarck was given highest priority to be equipped with full firecontrol capable sets when plannings were made.

Feinpeilung

Feinpeilung.png (188.85 KiB) Viewed 3965 times

Entfernung fein (=Messkette unit=Aufschlagmessgerät) its module wich provides a "zoomed" cutout from the range tube approximately 1000 m long

Aufschlagmessgerät.jpg (22.95 KiB) Viewed 3965 times

[hans zurbriggen]

Thank you Mr. Wahl,
it was also my feeling that Bismarck would have been given the most modern and efficient set before her mission.

If I understand correctly, the two modules for fine bearing and fine range measurement were 'modular' and could be installed on an existing Seetakt radar controller to enable fire-control without much 'effort' or large replacement works.

Do you know when 'Scharnhorsts' got their upgraded version ? Was it by November 1941 - February 1942 in Brest ? What about PG ?

Could you please confirm my understanding (from your post) that FuMG 39G (FuMO22 or 23) and FuMG 40G (FuMO 27) differ for the presence of these modules ? Aren't there other differences (e.g. shouldn't output power have been higher in FuMG 40G compared to FuMG 39G too, affecting effective range performances) ?

hans

[Thorsten Wahl]

First Gneisenau had improved range detection capabilities
against large target up to 28 km

Screenshot 2022-07-13 135845.jpg (22.38 KiB) Viewed 3896 times

they used Funkmess for splash detection
16 km for 28 cm shell
impact splash signs larger then target signs
28 cm salvos visible during flight

Screenshot 2022-07-13 145231.jpg (32.59 KiB) Viewed 3896 times

but from wording, I'm now sure, they had not the zoomed "Entfernung fein Display"
"Messkette-Modul" was present(Kurbeln an der _Kette)

Screenshot 2022-07-13 152315.png (104.81 KiB) Viewed 3895 times

...
But remember its February 1941

[hans zurbriggen]

Hello,
digging into this Forum, I have found a number of interesting posts from Mr. Saxton, among them this one: viewtopic.php?p=43770#p43770

It looks like Bismarck (quite logically) was upgraded in her Seetakt radar set before sailing, getting FuMO 27 (FuMG 40G) version instead of previous FuMO 23 (FuMG 39G, unit 11 and 17 as kindly mentioned by Mr. Nilsson).

Could Mr. Saxton (or anybody else here) provide document mentioned in his post (or reference to it) ?

hans

[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!