13 .5 inch monitors

Discussion in 'Alternate History Discussion: After 1900' started by tigercat, Oct 8, 2019.

  1. Peg Leg Pom Well-Known Member

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    Coastal Defence Battleship, so CDB?
     
  2. Dave Shoup Well-Known Member

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    The British kept Erebus and Terror in commission during the interwar era for training duty, but had scrapped or converted several similar ships in the same period. By the time there was a perceived need and money for similar ships in 1940-41 (when Roberts and Abercrombie were laid down), there were enough "spare" 15 inch turrets and guns to equip them.

    If the British decided in 1936 to order a modified King George V, expediting construction by using three existing twin 15 turrets per ship in place of the planned new twin/quad 14 inch turrets, then perhaps the three twin turrets still aboard Iron Duke might have been seen as the best options available for "new" monitors laid down as part of the same emergency program.
     
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  3. TonyA Curmudgeon like, but nastier

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    That has always seemed like the juxtaposition of two decent ideas, get a new, fast BB in service quickly and some well armed monitors, to boot.
     
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  4. tigercat Well-Known Member

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    I suspect that existing Monitors were special ships under Washington just because they didn't fit any other pigeon holes .

    Washington was aimed at preventing an arms race . I can't see an arms race developing over monitors in same way as no one is going to restrict coastal artillery . Monitors aren't going to be facing off in line of battle

    Love that diagram for Coastal Defense battleship .

    Were 12 inch monitors scrapped due to lack of percieved need in peacetime ? or because they were a rushed job and could only make 6.5 knots on a good day , downhill.....
     
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  5. CV12Hornet Well-Known Member

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    That, and their guns were antiques even by 1914 standards.
     
  6. Peg Leg Pom Well-Known Member

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    They had come off the ancient Majestics.
     
  7. Dave Shoup Well-Known Member

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    Well, yeah. How many "spare" 15 inch/42 twin turrets were available in the 1930s is a question of definitions, but even with the four that (historically) went into Vanguard and (presumably) at least the one that went into Roberts - setting aside the treaty issues - that provides at least enough for one capital ship, and two spare turrets (which would be enough for the two new Roberts class monitors, for that matter). If they could have scared up one more turret, they could have completed two capital ships, and armed three new monitors with the 13.5/45 twin turrets from Iron Duke.
     
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  8. Spencersj345.346 Well-Known Member

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    In fairness the real limiters on RN capital ship production in this time period were principally limited armor production capacity and limited gun turret production capacity with lesser problems as related to gun, engine and fire control system production, building a somewhat weakly armed capital ship or two will only result in shortages as related to armor(which was bad enough otl as related to the KGV's especially since the armor plate order from the Czechs wasn't delivered before Munich happened and the steelworks fell into German hands) in the building of properly armed capital ships.
     
  9. Dave Shoup Well-Known Member

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    Understood, but presumably going with 3 x 2 15 inch/42 as main armament could have advanced a fast battleship's commissioning date somewhat. Call her Resistance (so as to not confuse things with KGV) but build her in place of the (historical) KGV, and presumably she's operational in mid-1940, rather than late in the year. Be a useful ship in the Atlantic or the Med, and since Queen Elizabeth didn't recommission until 1941, she helps significantly in terms of the numbers of modern and modernized ships in the RN. She also gives Renown a modern running mate, so it is possible that Hood or Repulse might go in for a modernization, even after the war begins...
     
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  10. tigercat Well-Known Member

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    Would the Dutch have found a pair of Monitors useful ?
     
  11. Dorknought Well-Known Member

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    Not as useful as more submarines.
     
  12. Dorknought Well-Known Member

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    When the KGVs were started the 14" limit was in place and they couldn't wait for the escalation to 16" which would still put ships with 25 year old armament at a disadvantage.
     
  13. perfectgeneral Velocireader. Highly socially inept. CMII Donor

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    Well, due to arms limitation treaties, they couldn't keep the Orions. Newer crappier ships would have to convince other signatories that they were no threat. Even a single 13.5in gun on 8,000t looks a bit like the heaviest of cruisers. You would have to limit top speed to 10knots and range to 3,000nm. Harbour guardians with no sea fighting capability. They would give the heavy armour manufacturers something to bid for.


    @Peg Leg Pom , it is a great proposal, but by 1930, with no new treaty in sight, I think the next battleship would be more like a Lion or G3.
     
  14. Father Maryland Enemy of Neo Secesh Everywhere

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    Another benefit of monitors is speed of construction. HMS King George V was laid down 1 January 1937 launched 21 February 1939 and commissioned 11 December 1940 totaling 1,440 days.

    HMS Ereberus was laid down in 12 October 1915 launched 19 June 1916 and commissioned 2 September 1916 totaling 326 days.

    Frankly in a lot of ways it would make more sense to build more monitors and aircraft carriers rather then BB's like the King George V's.
     
  15. marathag Well-Known Member with a target on his back

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    But where to be used? Shelling Germany's coast? Defence of England's Coast? That's a hard sell, I think in 1936.
     
  16. SsgtC Ready to Call it a Day

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    Only using hindsight though. While we all know that battleships are dead as viable warfighting platforms by the end of WWI, the people making those decisions, dont. Carriers and carrier borne aircraft were extremely limited in what they could do until around the mid/late 30s. And even then, except for the British, Naval Aviation was essentially grounded at night. And it was grounded for all navies in bad weather. So with that in mind, even if you know that battleships are useless except for shore bombardment, you still need them for night actions and engaging in bad weather when your aircraft are gounded.
     
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  17. Oldbill Well-Known Member

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    This is a concept that small navies would have welcomed. For example both Finland and Siam had CD vessels built in the interwar period, having an affordable, well built ship would have been welcomed by them amongst others. These might also be useful as training vessels/flagships in Dominion nations. If they did this I wonder if the USN would follow suit, keeping the Ozark class in service.
     
  18. tigercat Well-Known Member

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    How much did 15 inch monitors cost ?

    15 inch coastal batteries for 3 guns looks like they cost 400 000 pounds or at least that was the Singaporean contribution for the Johore battery
     
  19. Dave Shoup Well-Known Member

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    The escalator clause was available if Japan or Italy had refused to sign by 1 April 1937; all five KGVs were laid down that year, two before and three after the deadline. Given the strategic situation, designed (or redesigning) one or two of the KGVs to accommodate 3x2 15/42 would not have been an impossible task, and the fact the guns and turrets existed would have sped up their commissioning dates. As far as the weapons being an existing design, the British were happy enough to design Vanguard around these same guns.
     
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  20. Dorknought Well-Known Member

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    Guns and turrets have a longer lead time. The 15” turrets require updating and that also requires gun pits already used for new build 14” turrets. 6 15” guns is a really sub optimal solution. The Vanguard was only seriously considered once war was certain.