I took Herr Nilsson's tip and had a look at the Deutsche Digitale Biblithek searching for Bauvorschrift. One of the first is for ersatz Gneisenau in the Mackensen class. The builder's contract for that ship ran to 835 pp all in Gothic typeface. This was in November 1914 and so does not include the increases in turret and barbette protection that were later made as a result of war experience.
Right at the start there are a lot of penalties the builder would suffer if the ship did not meet expectations. If the hull was x% overweight then a penalty of x*2% would be added to the cost but this did not apply if the hull overweight was less than 100 mt. There were similar penalties if the boilers and turbines came out overweight, this time with an allowance of 50 mt. However, if hull was overweight but the machinery came out light, or vice versa, then there was no penalty if the ship was not overweight overall and provided there was no disadvantage to the ship. If the ship could not make the designed speed, both on the one hour and six hour bases, then the penalty increased for every 0.1 knot the ship was slow. If the ship was more than 0.5 knots slow, on either basis, it could be rejected and would need to be modified. There were also penalties if the machinery were less economical than specified in the contract. In the general requirements it was stated that apertures of all kinds in bulkheads should not be near plate edges and that the edges of the apertures should be strengthened to compensate (as far as possible) for the weakness created by the aperture. Watertightness of bulkheads was to tested with water up to a height of 9.4 m, 1 m over the CWL.
The citadel of this ship extended from frame 37 to frame 146. With a frame spacing of 1.2 m this gave a citadel length of 130.8 m (429 ft). Gneisenau of 1934 had a hull of virtually identical dimensions but had a citadel around 153 m in length. Whereas other countries reduced the length of capital ship citadels after WW1 the Germans lengthened theirs. This was probably necessitated by the need to accommodate a larger amount of equipment under a low main armor deck. The turrets were to weigh about 770 mt, the first figures I have seen for the 35 cm gun, and the internal barbette diameter was 9,2 m. The lower edge of the main belt was 1700 mm below the CWL, which was at 8400 mm above the keel, and the upper edge 70 mm above the outer edge of the battery deck. As the outer edge of the latter deck was 11.55 m above the upper edge of the flat keel the belt depth appears to have been about 4920 mm. Only 1500 mm of the belt was at maximum thickness, running from 1150 mm above the CWL (level with the lower armor deck) to 350 mm below. Belt thickness was not given: these armor plates would be delivered by rail to the shipbuilder. Either Thoddy or Delycros recently posted on this site a drawing showing such a belt. The hull strake below the belt consisted of a box section with the inner layer being 16 mm thick and the outer 12 mm. The space between was to be filled with wood and naval lime. The outer layer served as a support of the belt. Bismarck also had such a layer but it was triangularly shaped. Others have said this layer was for protection from fragments of near misses but here it is said to be for support of the belt.
The torpedo bulkhead ran from frame 37.5 to frame 146. The layer in the double bottom was 30 mm thick. Above that to 600 mm above the lower armor deck it was from frame 37.5 to 72.5 and from frame 121 to 146 it was 60 mm thick and elsewhere it was 45 mm thick. The TB was extended fore and aft as a structural bulkhead, stepping down in thickness through 20, 16 and 12 mm plates for structural continuity purposes. The individual 45 and 60 mm plates extended from top to bottom with the former being 3.7 m wide and the latter 3.0 m wide. [On the Dreadnought Project there are plans of Friedrich der Gross showing its TB was made up of a number of rows of smaller plates that overlapped for rivetting purposes. So, it may be that larger sized plates of these thicknesses became available at about this time, which would also have allowed some weight to be saved compared with the use of smaller plates.] The transverse bulkheads at frames 37, 46.5 and 143 were partially 30 mm thick for torpedo protection. In addition, the middle platform deck was partially 30 mm thick between frames 37 and 46.5, and the upper platform deck was 30 mm thick between the torpedo bulkheads from frame 143 to frame 146, again as a protective measure against torpedoes. This is the first time I have seen reference to such underbottom protection in German ships. However, Scharnhorst (1934) did have 20 mm Wh under her magazines fore and aft,
Neil Robertson
Right at the start there are a lot of penalties the builder would suffer if the ship did not meet expectations. If the hull was x% overweight then a penalty of x*2% would be added to the cost but this did not apply if the hull overweight was less than 100 mt. There were similar penalties if the boilers and turbines came out overweight, this time with an allowance of 50 mt. However, if hull was overweight but the machinery came out light, or vice versa, then there was no penalty if the ship was not overweight overall and provided there was no disadvantage to the ship. If the ship could not make the designed speed, both on the one hour and six hour bases, then the penalty increased for every 0.1 knot the ship was slow. If the ship was more than 0.5 knots slow, on either basis, it could be rejected and would need to be modified. There were also penalties if the machinery were less economical than specified in the contract. In the general requirements it was stated that apertures of all kinds in bulkheads should not be near plate edges and that the edges of the apertures should be strengthened to compensate (as far as possible) for the weakness created by the aperture. Watertightness of bulkheads was to tested with water up to a height of 9.4 m, 1 m over the CWL.
The citadel of this ship extended from frame 37 to frame 146. With a frame spacing of 1.2 m this gave a citadel length of 130.8 m (429 ft). Gneisenau of 1934 had a hull of virtually identical dimensions but had a citadel around 153 m in length. Whereas other countries reduced the length of capital ship citadels after WW1 the Germans lengthened theirs. This was probably necessitated by the need to accommodate a larger amount of equipment under a low main armor deck. The turrets were to weigh about 770 mt, the first figures I have seen for the 35 cm gun, and the internal barbette diameter was 9,2 m. The lower edge of the main belt was 1700 mm below the CWL, which was at 8400 mm above the keel, and the upper edge 70 mm above the outer edge of the battery deck. As the outer edge of the latter deck was 11.55 m above the upper edge of the flat keel the belt depth appears to have been about 4920 mm. Only 1500 mm of the belt was at maximum thickness, running from 1150 mm above the CWL (level with the lower armor deck) to 350 mm below. Belt thickness was not given: these armor plates would be delivered by rail to the shipbuilder. Either Thoddy or Delycros recently posted on this site a drawing showing such a belt. The hull strake below the belt consisted of a box section with the inner layer being 16 mm thick and the outer 12 mm. The space between was to be filled with wood and naval lime. The outer layer served as a support of the belt. Bismarck also had such a layer but it was triangularly shaped. Others have said this layer was for protection from fragments of near misses but here it is said to be for support of the belt.
The torpedo bulkhead ran from frame 37.5 to frame 146. The layer in the double bottom was 30 mm thick. Above that to 600 mm above the lower armor deck it was from frame 37.5 to 72.5 and from frame 121 to 146 it was 60 mm thick and elsewhere it was 45 mm thick. The TB was extended fore and aft as a structural bulkhead, stepping down in thickness through 20, 16 and 12 mm plates for structural continuity purposes. The individual 45 and 60 mm plates extended from top to bottom with the former being 3.7 m wide and the latter 3.0 m wide. [On the Dreadnought Project there are plans of Friedrich der Gross showing its TB was made up of a number of rows of smaller plates that overlapped for rivetting purposes. So, it may be that larger sized plates of these thicknesses became available at about this time, which would also have allowed some weight to be saved compared with the use of smaller plates.] The transverse bulkheads at frames 37, 46.5 and 143 were partially 30 mm thick for torpedo protection. In addition, the middle platform deck was partially 30 mm thick between frames 37 and 46.5, and the upper platform deck was 30 mm thick between the torpedo bulkheads from frame 143 to frame 146, again as a protective measure against torpedoes. This is the first time I have seen reference to such underbottom protection in German ships. However, Scharnhorst (1934) did have 20 mm Wh under her magazines fore and aft,
Neil Robertson
statistics: Posted by neilrobertson1 — 3:59 PM - 1 day ago — Replies 1 — Views 149