Kriegschiffsbau by H Evers (1943)

Discussions about the history of the ship, technical details, etc.

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RobertsonN
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Kriegschiffsbau by H Evers (1943)

Post by RobertsonN » Tue Apr 21, 2020 7:26 pm

This morning a package came probably before I got up. It was from Karlsruhe and contained the copy of this book I ordered the week before last. It is in very good condition for its age. I wonder how many previous owners it has had? It is in what is now normal text and not the Gothic that is often used in Germans documents of this period, which makes it easier to read.

It contains 486 pages. It is easier to say what it does not contain. For reasons of secrecy there is nothing about German WW2 ships and there seems to be very little about boilers, machinery and electrical equipment.

On the other hand, there are some sections on subjects I had not expected. There is a discussion about the results of German experiments with diving shells, including a diagram showing two typical trajectories of such shells. There is a section on shipbuilding steels and armor with a table showing the material properties: UTS, elastic limit and %elongation. For armor plates there are no such data but instead the remark 'proving ground tests decisive'. There are some proving ground tests with 38 cm shells. Two of these were at obliquities of 70 and 72 deg. That is higher than I believed the Germans tested. A lightly capped base fused HE shell at 72 deg with a striking velocity of 440 m/s made a large hole in and broke the 110 mm thick soft nickel plate into three pieces. The shell gave a partial detonation on impact.

There is a lot about stability and a table giving the role periods of various ships; also a good bit about ventilation systems and the flooding of magazines. The purpose of the citadel armor above the main belts of ships is given: to defeat large APC at higher obliquity and all non-APC and medium calibre APC. Under the function of the lower armor deck is given preventing water above this deck getting below it and stopping water below this deck getting above it [It would seem that ships with only a high armor deck might have a problem with water rising from below.] The block coefficients of various British and German ships of the First War are stated. These are sometimes different from those that Friedman gives in his battleship design book. The pocket on the inner cover contains very detailed plans of the battleship Bayern.

Anyhow I cannot start reading it yet as I am still on one of Friedman's tomes. The writing style appears to be easier to read than Friedman's,

Neil Robertson

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Re: Kriegschiffsbau by H Evers (1943)

Post by RobertsonN » Wed Apr 22, 2020 10:38 am

My copy cost 35 euros + 12 euros for postage. This is not much in relation to some out of print books such as Raven and Roberts. There are still a number of copies of this book available. I got this one through a site called Booklooker which I had not heard of,

Neil Robertson

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Re: Kriegschiffsbau by H Evers (1943)

Post by marcelo_malara » Wed Apr 22, 2020 4:07 pm

I paid 100 U$ for Raven´s British cruisers. Anyway, it is worth every cent.

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Re: Kriegschiffsbau by H Evers (1943)

Post by RobertsonN » Sun Apr 26, 2020 10:02 am

This book is not just a narrow text on naval architecture. It starts out with a very general overview of the whole naval field. The indispensability of aircraft carriers is accepted for extended naval operations over a wide area. The limitations of then current submarines through having engines dependent on atmospheric air is acknowledged. Aircraft are able to achieve concentration of force through their high speed and power of manoeuvre whereas in ships concentration of force is best achieved through larger unit size. The problem of unit size is examined. For countries with extended interests such as Britain with its Empire and enormous merchant marine there was a need for a division of forces and smaller unit size whereas those which can concentrate their forces in one region are likely to go for larger unit size. But there was a need for a certain minimum number of each ship type so as to take into account mishaps, war losses and refits. The writing style is academic and the German fairly modern but with one or two words spelled differently from now. The most obvious parallel of this book is that of Hovgaard.

Looking ahead I see there is a cross-section of the King George V class battleships. The general layout is correct and the author sees it as a development of the US standard battleships. He assumed that the KGV had a lower armor deck as well as the upper one but with no slope. He also believed that a fairly conventional heavy conning tower was incorporated into the forward superstructure in the correct position and deduces that a heavy communications tube supported the weight of this and the DCT above it. The author saw the standard battleships as the first US generation of ships on the raft body principle. He says there was a need to limit lists and trims on these so that the armor belt was not submerged. Such ships generally adopted fuel loadings and water exclusion measures such as tubes to help achieve this objective. [For example, by rearrangement of the fuel loading in South Dakota (2) the calculated list after one torpedo hit was reduced to 3.7 deg with a remaining armor freeboard of 5.1 ft from values of 7 deg and only 0.1 ft in Washington.] On the same lines, he says that once the full load displacement of raft body ships was established then this value should not be exceeded whether by equipment fitted in refits or increases in fuel, water, ammunition, spares, etc. Additions should always be compensated for by corresponding equipment removed,

Neil Robertson

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Re: Kriegschiffsbau by H Evers (1943)

Post by RobertsonN » Thu Apr 30, 2020 2:01 pm

I quote from Section 4 on p. 288 about equipment for counterflooding. It contains remarks about the loss of Audacious that I have not seen elsewhere:

'The principle of the balancing pipe lies in outer compartments on opposite sides of the ship being connected by a straight pipe of large diameter. The pipe does not have valves to the ship's bottom. The ship sails with all dividing slides in this pipe open. At fully flooded cells on one side, the corresponding cells on the other side are simultaneously flooded through the pipe and therefore the list automatically corrected. The equipment has the advantage of great simplicity, automatic action and relatively quick list correction. Its great disadvantage lay in that for fully flooded cells on both sides of the ship's ends, the trim was doubled and, for large leaks, dangerous trim changes can occur.'

'The English battleship Audacious, which sustained a mine hit in the stern, was equipped with such balancing pipes. The ship was through the complete flooding of these cells so down at the stern, that in the existing high sea state the stern was submerged and she sank as a result.'

Neil Robertson

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Re: Kriegschiffsbau by H Evers (1943)

Post by RobertsonN » Thu Apr 30, 2020 5:55 pm

I add this as a separate post as the editing function is not working at the moment.

I missed out a sentence at the end of the first quoted paragraph of the last post. That sentence is:

'To counter this, there must be sufficiently large trim cells in the ship's ends.'

Neil Robertson

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