P-class (ironclad)
| P-class | ||
|---|---|---|
| Overview | ||
| Type: | Ironclad | |
| Units: | planned: 12 in service: 0 |
|
| Technical specifications | ||
| Displacement: | Draft: 25,700 t |
|
| Length: | 216.5 m | |
| Width: | 24.4 m | |
| Draft: | Maximum: 7.3 m | |
| Speed: | Maximum: 33 kn | |
| Crew: | 1000 men | |
| Range: | 16,000 nautical miles at 16 knots | |
| Drive: | 12 MAN diesel engines on 4 screws diam. 4.3 m |
|
| Armament: |
|
|
The armored ships of the new type, which were referred to as type P cruisers in the vernacular of the Kriegsmarine , are a project of the German Kriegsmarine that was never carried out.
planning
The class was designed in 1938 as the successor to the Germany class . The specifications were aimed at a faster and better protected version of the predecessor. In many ways it is a further development of the original designs of Panzerschiff D and Panzerschiff E from 1934, which were demolished after only a short construction period and finally completed as a completely new construction as battleships of the Scharnhorst class . The P-Class thus represents an evolutionary development of the original armored ship concept, which was adapted to the conditions of a modern naval war (as it was imagined in the late 1930s). Above all, this meant higher speed and range, while the possibilities of an air war over sea were not or could not be foreseen.
The first three ships were to receive the 28 cm armament that became available when Scharnhorst and Gneisenau were converted to 38 cm towers .
Since the ships were intended for the trade war, they were designed to be superior to heavy cruisers in terms of armament and armor protection. Battleships should be able to avoid them due to their superior speed and sea endurance. The ships were expected to have a range of 17,000 nm at a speed of 19 kn.
The military requirement for a very high maximum speed of 34 kn at last required an engine power of 180,000 WPS and led to an engine system of approx. 100 m in length with a very narrow ship. Instead of the originally planned 9-cylinder in-line diesel engines (weight 32 kg / hp) of the H-class , the use of 24-cylinder V-engines (weight 22 kg / hp) was ultimately assumed. In addition, the dimensions of the engine rooms in length and height could be significantly reduced. Despite the improvements in the machinery, a satisfactory design could not be achieved.
Due to the elongated machinery, the armament was very much pressed to the ends of the ship and unfavorable sea characteristics were to be expected. Furthermore, the design of adequate armor protection and protection against torpedo hits proved difficult.
The further discussion of the project at the end of May 1939 ff. In the new building committee of the High Command of the Navy then evolved directly to the O-class ,
- a three-tower ship with twin towers of larger caliber,
- Combination of the 15 cm medium artillery and 10.5 cm anti-aircraft artillery into a unit armament of around 13 cm
- an engine size adapted to the type of ship, which ensures the necessary protection at the height of the armored deck and the width of the torpedo protection.
According to letter A Va 477/39 g.Kdos. From 13 July 1939 of the naval commander in chief, the designation "battleship" was introduced for the previous cruiser type "P". The cruiser type P ceased to exist.
In the period that followed, work on the concept of the “trade destroyer” was only continued on a project basis with reduced priority.
Class name
The designations "P1" to "P12" were assigned to the planned ships. These designations should not be confused with the designation cruiser "P", the fourth cruiser of the M-class from the cruiser building program.
construction
The Z-Plan provided for twelve of these ships; construction should begin in 1940 and be completed in 1948. The construction time was estimated at 3 years per ship.
technical description
Weights
The preliminary weight compilation reflects the planning status at the beginning of May 1939 shortly before the project was abandoned.
| designation | Weight [t] |
|---|---|
| Hull | 7,200 |
| Armor (without rotating armor) | 7,070 |
| Main machines | 4,040 |
| Auxiliary machines | 1,050 |
| Artillery armament | 3,100 |
| Torpedo armament / smoke systems | 70 |
| Aircraft facilities | 80 |
| Barrages | 20th |
| equipment | 683 |
| water | 201 |
| Reserve 2% | 486 |
| Type displacement | 24,000 |
| 1/3 fuel oil | 1,250 |
| Lube oil / feed water | 405 |
| 1/2 aircraft resources | 18th |
| Construction displacement | 25,673 |
| Feed water | 45 |
| Lubricating oil | 150 |
| Fuel oil | 2,500 |
| Aircraft resources (reserve) | 18th |
| Fresh water reserve | 119 |
| Ship fully equipped | 28,505 |
| Fuel reserve | 600 |
| In-service reserve | 300 |
| Maximum ship weight | 29,405 |
Machine system
At the de facto final meeting of the offices (K-Office, Marine Weapons Office), the drive alternatives were discussed as follows: Expected performance of the 4-shaft system with 12 V motors (15,000 WPS) totaling 180,000 WPS.
- Fuel: 4,350 t
- Fuel consumption machine system: 0.22 kg / WPS and hour
- Fuel consumption for general ship purposes: 0.8 t / hour
| Speed [sm / h] |
Power [WPS] |
Range- [sm] |
|---|---|---|
| 14th | 8,000 | |
| 18th | 16,400 | |
| 19th | 18,800 | ~ 17,000 |
| 30th | 80,000 | |
| 33 | 145,000 | |
| 33.5 | 160,000 | |
| 34 | 180,000 |
Alternatively, a machine system of 150,000 WPS on three shafts with a slightly smaller ship was discussed later. In earlier drafts, the machinery was represented by H-engines of 9,000 hp. Compared to this system, the V-engine system already represented a considerable advance.
| V engine | H engine | |
|---|---|---|
| Weight: | 22 kg / hp | 32 kg / hp |
| Machine room length: | 13.5 m | 16.5 m |
| Engine room height: | 7.1 m | 9.0 m |
| Height of foundations: | 1.5 m | 2.0 m |
| Power with 12 engines | 180,000 hp | 165,000 hp |
Armor
At the meeting of the offices on May 2, 1939, two "final" armor alternatives were also discussed:
A) Side armor with armor
- Armor: 60 mm
- Main armor inclined approx. 18 °: 110 mm
- Upper deck: 20 mm - 30 mm (above engine rooms)
- Main armored deck: 60 mm
- Torpedo bulkhead: 30 mm
- Citadel: 20 mm
B) classic arrangement with external main armor and armored deck embankment.
- main vertical armor: 120 mm
- Upper deck: 20 mm - 30 mm (above engine rooms)
- Main armored deck: 60 mm including 60 mm embankment
- Torpedo bulkhead: 30 mm
- Citadel: 20 mm
With both alternatives, reinforcing the armored deck by 5 mm would cost around 100 t of additional weight.
"Although alternative A offers absolute protection against penetration of the side protection of 20.3 cm projectiles at all distances into the vital parts of the ship", "the classic arrangement was given preference because the waterline protection is better, which is important for the commercial destroyer" .
On May 30th came the "end". An (additional) test has shown that the embankment forms an extremely weak point in the ship when the side armor overshoots, it will penetrate:
at position 0 dec from 216 hm (across to the enemy)
at position 2 dec from 210 hm
at position 4 dec from 193 m
at location 6 dec from 154 m
The part of the belt armor lying above the level of the horizontal armored deck thus no longer fulfills its main task under certain conditions, in particular to protect the sloping embankment in the case of anterior or posterior shooting directions which are desirable for various reasons.
artillery
6 × 28 cm SK C / 34 (L / 54.5) ) in two triplet towers (Drh. L. C / 28)
- Tower weight: 675 t each, of which armored armored vehicles approx. 78 t
- Ammunition: 120 rounds per tube of 550 kg each (including propellant charge)
4 × 15 cm SK C / 28 (L / 55) in two twin towers (Drh. L. C / 28)
- Tower weight: 100 t each, of which armored armored personnel carriers approx. 10 t
- Ammunition: 120 rounds + 20 light grenades per barrel, each 75 kg (including propellant charge)
8 × 10.5 cm SK C / 33 (L / 65) in four twin towers (Drh. L. C / 38)
- Tower weight: 43.5 t each, of which armored armored personnel carriers approx. 14 t
- Ammunition: 400 grenade cartridges + 30 light grenade cartridges per barrel, each weighing 32.5 kg
8 × 3.7 cm SK C / 30 (L / 83) in four twin mounts (Dopp L. C / 30)
- Weight: 3.7 t each
- Ammunition: 1,000 cartridges per tube, each weighing 3.2 kg
8 × MG C / 30 in eight single mounts (L. C / 30)
- Weight: 0.4 t each
- Ammunition: 2,000 cartridges per barrel, each 0.5 kg
literature
- Siegfried Breyer: The Z-Plan - Striving for a World Power Fleet , ISBN 3-7909-0535-6
- Siegfried Breyer: Battleships and battle cruisers 1905-1970 , ISBN 3-86070-044-8
Individual evidence
- ↑ BA-MA-RM-20-1913; General questions of type for battleships, ironclads and cruisers 1939-40; The President of the New Building Committee at the High Command of the Navy Nb.A.14 / 39 g.Kdos; Berlin May 23. 1939
- ↑ BA-MA-RM-20-881; Shipbuilding plan type issues January 18, 1937 - June 5, 1941; Naval Command Office AV s 8000/38 Gkds. Berlin December 23, 1938 Betr. New building plan "Z" - pronunciation of the offices
- ↑ BA-MA-RM-20-1913; General questions of type for battleships, ironclads and cruisers 1939-40; Office for Warship Building B.Nr. K 500/39; Berlin May 2nd. 1939.
- ↑ BA-MA-RM-20-1913; General questions of type for battleships, ironclads and cruisers 1939-40; Office for Warship Building B.Nr. KIII 189/39 g.Kdos .; Berlin May 5, 1939; Contribution of AV g to the assessment of cruiser type "P"
- ↑ BA-MA-RM-20-1913; General questions of type for battleships, ironclads and cruisers 1939-40; Office for Warship Building B.Nr. KIII 189/39 g.Kdos .; Berlin April 6, 1939; Minutes of the meeting concerning cruiser P on April 4, 1939 with office chief K ..
- ↑ BA-MA-RM-20-1913; General questions of type for battleships, ironclads and cruisers 1939-40; Naval weapon office; MWA 1249/39 g.Kdos .; Berlin May 30, 1939; re: draft cruiser type P
- ↑ BA-MA-RM-20-1913; General questions of type for battleships, ironclads and cruisers 1939-40; MWA I 749/39 g.Kdos. Artillery weight cruiser P Berlin May 3rd. 1939.