Montana class
| Montana class | |
|---|---|
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| Overview | |
| Type | Battleship |
| Origin of name | States of the USA |
| units | 5 planned, 0 built |
| Technical specifications | |
| length | 272.3 m |
| width | 36.8 m |
| Machine performance | 212,000 WPS |
| speed | 28 kn |
| machinery | 4 geared turbines, each 43,000 WPS |
| Drive shafts | 4th |
| boiler | 8 vertical Babcock & Wilcox two-drum high-pressure vessels (operating pressure 39.7 Atü (38.9 bar) at 454.4 ° C) |
| E-system | 10 turbo generators each 1250 kW and two diesel-powered auxiliary generators of 500 kW each |
| Armament |
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| Planes | 3 × OS2U Kingfisher or SC1 Seahawk |
| Catapults | 2 × 20.7 m long, swiveling |
| radar |
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As a further development of the Iowa class, the battleships of the Montana class were the culmination and end point of battleship construction in the United States . If these ships had been built and completed, they would have been the most powerful and heavily armored battleships in the world to date.
Planning and development history
On July 19, 1940, the Two-Ocean Navy Act was passed, which made a strong increase in the fleet tonnage and a considerable increase in ships possible. Among other things, many more battleships could now be built in shipyards .
Work on these possible battleships had been going on since 1938. A key point on which the conception of these battleships was based was the 406 mm L / 50 gun with its MK 8 tank explosive shell with a projectile mass of 1225 kg.
After the Iowa class was launched, a class of faster battleships (over 32 knots ), the US Navy “reconsidered” the traditional characteristics of battleships: strong armor and high striking power. In this class, speed wasn't that important. To draw a demarcation from the speed of the Iowa- class, which were referred to as fast battleships, the Montana- class was referred to as slow battleships. The planned speed of 28 knots was by no means slow for the time, but rather a normal speed for battleships. In the first planning studies, however, the tonnage was limited to 45,000 ts. The problems associated with this restriction of finding adequate protection against the strongest enemy shells could only be bought at a reduced speed, i.e. unlike the Iowa class, where speed was the focus and therefore the armor was somewhat lower.
In the first draft series from 1939, consisting of twelve drafts, the planners adhered to the given restrictions. The design series had the designation BB 65, whereby the individual designs were counted up with the alphabet, i.e. BB 65A, BB 65B etc. The construction designation is interesting in that two more Iowa- class ships were ordered in September 1941 , the BB 65 and BB 66. For the further planning of the slow battleships the designation 'BB 65' was retained, which caused confusion here and there. For the main artillery , too, the planners adhered to the 406 mm caliber , with the exception of one draft in which the 356 mm caliber was expected. In the drafts, the number of towers fluctuated between three and four, and quadruple towers were also calculated. The armor in all designs was 406 mm. For the medium artillery , the classic variant of 20 × 127 mm was chosen, in twin towers of five on each side. In the case of the BB 65D draft, twelve 152-mm guns were used.
Another series of designs from September 1939 (again designated BB 65A, BB 65B etc.) was calculated with 47,000 ts. From here it was clear that the main artillery should consist of twelve 406 mm guns. The number of towers had not yet been determined: the majority of the designs contained three quadruple towers, the remainder four triplet towers . In this series too, the middle artillery was mainly calculated with 20 × 127 mm, two designs were calculated with 12 × 152 mm.
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From October 1939 it was decided to increase the tonnage to 50,000–55,000 ts. In January 1940 there was a third series of designs, but this time it was numbered BB 65-1, BB 65-2, etc. In this series of designs, there was now agreement on the artillery: 12 × 406 mm and 20 × 127 mm. The improved version of the 127 mm appeared here for the first time, the 127 mm SK L / 54. The side armor of 406 mm was uniform in all designs of this series. The engine output fluctuated between 130,000 shaft horsepower for 27.5 kn (with the South Dakota class engine ) and 212,000 or 320,000 WPS for 31.8 or 34 kn. The displacement also fluctuated between 51,000 and 66,700 ts.
The next series of designs from 1940 was about reducing the large displacement of the previous series. The main and middle artillery and side armor remained constant. Some designs were calculated at high speed (33 kn) so that the displacement also increased again, in these cases between 65,000 and 67,000 ts, while the other designs managed with 48,000 to 57,000 ts.
The last series of designs from late 1941 / early 1942 came very close to the required goals. In this series, the final designation BB 67 appeared (the individual designs were marked with BB 67-1, BB 67-2, etc.). This series was about machine performance. The first two drafts were based on a 212,000 WPS machine system (namely that of the Iowa class) for 28 knots, the remaining 172,000 WPS also for 28 knots. In this case, a large reserve of power has apparently been included in the design.
The final design was then approved in early 1941. This came very close to the design BB 67-4 of the last series. In this class of ship, the Panamax dimensions were exceeded for the first time, i.e. the ability to pass the Panama Canal was waived . This decision was derived from the requirement for the best possible descent safety, which made a very wide underwater hull ( torpedo protection belt ) necessary. Furthermore, the demand for a ship that could hold its own against the largest Japanese surface units could also be read here. This consideration arose from the still prevailing conviction that the victory over the Japanese should be achieved, among other things, with the help of superior battleships. The final version was then available in March 1941 and its amendments in June 1942.
The requirements and then the actual design are shown in the following two tables:
Requirements for the Montana class
| Standard displacement | 58,000 ts |
| Length in KWL | no more than 272.3 m |
| width | greatest possible stability |
| Armament |
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| Armor / protection | Protection against 1225 kg tank explosive shells at a distance between 16,500 and 29,260 m |
| drive | 212,000 WPS for 28 kn |
| Driving range | 15,000 nm at 15 kn |
Actual Montana Class Committed Dates
| component | March 1941 | June 1942 |
|---|---|---|
| Standard / deployment displacement | 60,500 ts / 70,500 tn.l. | 63,221 ts / 70,965 tn.l. |
| Length in KWL | 272.3 m | 273.3 m |
| Width with outer armor | 36.8 m | 36.8 m |
| Width on mall edge | 35.96 m | 35.96 m |
| Armament |
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The naval shipyards in Philadelphia (three ships) and, with one ship each, those in New York and Norfolk were selected for the construction of the ships . The construction contracts went out on September 9, 1940, with the completion dates between July 1, 1945 and December 1, 1945 for the first and the last ship. $ 200 million per unit was estimated. The laying of the keel was delayed because the armaments industry was not yet in full swing and this had led to delivery problems for shipbuilding steel.
After the Japanese attack on Pearl Harbor , which led to the USA entering the war, and the course of the first months of the war, it became clear that the aircraft carrier had overtaken the battleship as the main combat ship and relegated it to the second rank. The then President of the United States , Franklin D. Roosevelt , issued a construction freeze on the ships on May 20, 1942. This decision resulted from the recent battle in the Coral Sea , in which aircraft carriers faced each other on both sides for the first time. Three weeks later the scenario was repeated at the Battle of Midway . The course of the battle confirmed Roosevelt's decision. On July 21, 1943, the Montana class was canceled without replacement.
In accordance with the tradition of the US Navy , the names of US states were chosen as ship names.
Construction
The design and hull shape was very similar to the Iowa class. Also, as with this one, the hull should be fully electrically welded. There were also no portholes , as it was believed that this measure should lead to improved longitudinal and lateral strength. Instead, the interior of the fuselage was artificially ventilated. The superstructures had a little less space than the Iowa class, but still required a length of 80 m. The reason was in the fourth triple tower. A spacious boat deck was planned between the chimneys and a rotating boat crane on each side of the second chimney. Two catapults for board aircraft were provided on the quarterdeck .
Armament / armor
The Montana- class armor was designed to withstand the following scenarios:
- 1225 kg 406-mm L / 50 tank explosive shells between 16,450 and 28,350 m
- 1060 kg 406-mm L / 45 tank explosive shells between 13,100 and 31,550 m
The arrangement of the armor was similar to that of the North Carolina class , but with greater thicknesses. The armor began just before the first tower and ended just after the last. The outer armor had an inclination of 19 °, which corresponded to the protective effect of 508 mm thick armor. The interior protection should be achieved by four longitudinal bulkheads, one behind the other, inclined by 10 °. The underwater protection was designed so that it could withstand mines and torpedoes of the time. The horizontal armor had three armored decks. A triple floor was provided to protect against mine detonations .
The main artillery was twelve 406 mm guns in four triple turrets. The weight of one broadside would have been 14,700 kg. The middle artillery was designed for 20 × 127 mm guns in twin turrets with five on each side. On the Montana class, the improved 127 mm L / 54 was to be used, which had a higher muzzle velocity than the L / 38 gun, which improved the range.
Propulsion system
The arrangement of the drive components had been improved compared to the Iowa class. This reduced the risk of failure. Each of the four turbine sets and the associated boiler were housed in a separate engine room. Due to the greater width of the hull, the turbines, boilers and auxiliary machines could be divided up very well. Maintenance work could also be carried out better thanks to this generous room layout. The total power should be 172,000 shaft horsepower . The machinery took up about 90 m of the ship's length.
Planned ships of the class
| Construction designation | Surname | Budget year | Shipyard | Keel laying | Launch | Commissioning |
|---|---|---|---|---|---|---|
| USS Montana (BB-67) | Montana | 1940 | Philadelphia Naval Shipyard | - / - | - / - | - / - |
| USS Ohio (BB-68) | Ohio | 1940 | Philadelphia Naval Shipyard | - / - | - / - | - / - |
| USS Maine (BB-69) | Maine | 1940 | New York Naval Shipyard | - / - | - / - | - / - |
| USS New Hampshire (BB-70) | New Hampshire | 1940 | New York Naval Shipyard | - / - | - / - | - / - |
| USS Louisiana (BB-71) | Louisiana | 1940 | Norfolk Naval Shipyard | - / - | - / - | - / - |
literature
- Siegfried Breyer: Battleships and battle cruisers 1921–1997. Bernard & Graefe, ISBN 3-7637-6225-6 .
Web links
- Dictionary of American Naval Fighting Ship (DANFS) on hazegray.org (English)
- Montana Class (BB-67 through BB-71) . ( Memento from October 29, 2013 in the Internet Archive ) Photos of models of the Montana class at history.navy.mil (English)
- NavSource Online - Battleship Photo Archive
- List of US Navy battleships on the Navy website.
- Images of the US Navy battleships
