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MidwayŚ77 Years Ago, Today.


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#881 lastdingo

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Posted 19 August 2019 - 0818 AM

The Kriegsmarine thought that its 37 mm gun needs a high muzzle velocity and good aim to hit moving targets at useful distances. They underestimated the importance of a high rate of fire.

 

 

Look at the extremely unusually high MV of the Kriegsmarine 37 mm ordnance.


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#882 Markus Becker

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Posted 19 August 2019 - 1427 PM

Thanks, didn't notice that until now. They should have gone with the Pom Pom's principle. Lower MV but higher RoF. Would have been perfectly reasonable for a gun designed in the early 30s when biplanes were still the norm.
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#883 lastdingo

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Posted 19 August 2019 - 1722 PM

Actually, I think the most sensible approach would have been a 30...37 mm Gatling with autonomous (battery) electrical power. This combination had been patented in 1893 (and shown a huge RoF soon after).

Such a 850 m/s MV Gatling with Minengeschoss (HEI) would have proved devastating at all ranges where the probability of hit was rather good.* There would have been very much firepower per gunner (gun layer, aimer), so training the gunner to be extremely proficient with reflex sight + tracer (tracer out to 3 km, ideally no two guns with overlapping angles would have the same colour unless spaced very much) would have been highly economical (training at low RoF).

 

I generally think that the light AAA of up to the 1950's had a weirdly low rate of fire. The quite improvised use of fighter guns (MG 151/20 and Mk 103) in a few mounts was an exception from the rule (even the quad 20 mm did not really have a high rate of fire). It was understood that machineguns would need a high RoF for AA (see quad Maxims, demands for high RoF with MG 42) and aircraft guns had a high RoF below 30 mm calibre, but light AAA tended to focus on heavier and faster projectiles rather than high RoF. The Kriegsmarine was an extreme case. Gatlings and water-cooled guns were easily able to cope with very high RoF, so one could have expected the navies to be on the high RoF side rather than the opposite!

 

 

*: Starshells and chasing spotter aircraft or airships away with heavy AAA could have been done with destroyer and light cruiser main guns and BB/BC secondary arty. CA could have used two dedicated starshell & heavy AAA 105 mm guns, akin to the flimsy actual USN cruiser AAA of the 30's.


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#884 DougRichards

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Posted 19 August 2019 - 1822 PM



Thanks, didn't notice that until now. They should have gone with the Pom Pom's principle. Lower MV but higher RoF. Would have been perfectly reasonable for a gun designed in the early 30s when biplanes were still the norm.

Except were not naval 37mm / 40mm also meant to have an anti-torpedo boat function?  So the idea would have been to keep MTB out of effective torpedo range, so a higher MV and thus flatter trajectory would have been useful.

 

And the ship[s that carried them usually had a fair number of 20mm mounts for volume of fire.


Edited by DougRichards, 19 August 2019 - 2027 PM.

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#885 lastdingo

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Posted 19 August 2019 - 1856 PM

AFAIK guns calibre 57 mm or better proved most capable against MTBs, I did not see 37/40 mm being mentioned as being really effective against them.

The British MGBs received some rare 6pdr (57 mm) guns to deal with German S-Boote ('E boats'). Heavy AAA used time fuzed shells to hit torpedo boats, hence the armoured bridge of German S-Boote since IIRC mid-WW2.


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#886 DougRichards

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Posted 19 August 2019 - 1913 PM

AFAIK guns calibre 57 mm or better proved most capable against MTBs, I did not see 37/40 mm being mentioned as being really effective against them.

The British MGBs received some rare 6pdr (57 mm) guns to deal with German S-Boote ('E boats'). Heavy AAA used time fuzed shells to hit torpedo boats, hence the armoured bridge of German S-Boote since IIRC mid-WW2.

 

Hogg mentions in one of his books on German artillery that the 37mm SK C/30 was sometimes mounted in coastal defence positions with a dual AA and surface role.  He further mentions that the shell would have been effective against aircraft but would be of limited effectiveness against MTB.

 

Even so, it was used in that role, and it was often the major armament of R Boats.

 

Having said that, the Colt 37mm AA gun was used in conjunction with 90mm AA guns for the same anti MTB role by the USA.

 

The original 1 1/2pdr pom pom shipboard were mainly intended for the anti MTB role, as aircraft had not yet been invented.  Of course as the aircraft was invented the idea was adopted for AA use as well.

 

The British did indeed come up with a useful 57mm coastal gun (that was mounted on some destroyers for use in the Channel), but attempts by both the British and Germany to produce a gun of around 50mm / 57mm for the intermediate AAA role were not particularly successful.


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#887 Ken Estes

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Posted 19 August 2019 - 1945 PM

High ROF for shipboard weapons has obvious limits when fleet logistics and replenishment are considered. None existing in 1939, Dingo's attempts to term contemporary judgement flawed just falls flat. We need to understand what people in Year XX thought they were doing, but the purpose of that is to understand what people thought and what was going on, not to ridicule their lack of prophecy.


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#888 Stuart Galbraith

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Posted 20 August 2019 - 0228 AM

 

Dont think so. The nearest used is blinker lights I guess."

Since it is the Navy, "carrier" pigeons  :D

 

 

Boom, Tish! :)


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#889 lastdingo

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Posted 20 August 2019 - 0525 AM

High ROF for shipboard weapons has obvious limits when fleet logistics and replenishment are considered. None existing in 1939, Dingo's attempts to term contemporary judgement flawed just falls flat. We need to understand what people in Year XX thought they were doing, but the purpose of that is to understand what people thought and what was going on, not to ridicule their lack of prophecy.

 

The mechanics of replenishing a 30 mm Gatling are simple. In fact, munitions replenishment becomes a lot simpler once you moved from clips to large linkless boxes. You can replace them as a whole, moving them around as a cart. All you need to do is to have a clean and not very much tilted deck and storage space in the superstructures to avoid requiring a lift. To resupply a 30 mm Gatling did likely require less personnel than to resupply a quad mount.

 

The mechanics of letting a triple primary arty mount reload as quickly at 20° elevation as could a twin mount at 5° were much more complicated than that, and that problem was solved during the 1920's.

 

Besides, I call you out for implying a lie; I did not ridicule.


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#890 Ken Estes

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Posted 20 August 2019 - 1346 PM

implying a lie? hahahahah


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#891 Markus Becker

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Posted 20 August 2019 - 1428 PM

Except were not naval 37mm / 40mm also meant to have an anti-torpedo boat function?  So the idea would have been to keep MTB out of effective torpedo range, so a higher MV and thus flatter trajectory would have been useful.
 
And the ship[s that carried them usually had a fair number of 20mm mounts for volume of fire.


Not by the early 30s any more. As far as I can tell MTB weren't a thing in the inter war years. DD were seen as the ones launching fish.
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#892 Markus Becker

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Posted 20 August 2019 - 1432 PM

How was replenishment usually defined? WAG: Rearm in home port or one of the many overseas bases if you are the RN? Underway replenishment would be a USN thing.

PS: AA ammo expenditure was underestimated too, so continental navies could have gone with high RoF guns.

Edited by Markus Becker, 20 August 2019 - 1435 PM.

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#893 lastdingo

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Posted 20 August 2019 - 1445 PM

Germans even resupplied subs by subs - including a technique for transferring fuel while BOTH were submerged.

Graf Spee etc were resupplied by Troßschffe; replenishment ships.


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#894 Rick

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Posted 20 August 2019 - 1643 PM

How was replenishment usually defined? WAG: Rearm in home port or one of the many overseas bases if you are the RN? Underway replenishment would be a USN thing.

PS: AA ammo expenditure was underestimated too, so continental navies could have gone with high RoF guns.

Both for the USN.


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#895 DougRichards

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Posted 20 August 2019 - 1701 PM

 

Except were not naval 37mm / 40mm also meant to have an anti-torpedo boat function?  So the idea would have been to keep MTB out of effective torpedo range, so a higher MV and thus flatter trajectory would have been useful.
 
And the ship[s that carried them usually had a fair number of 20mm mounts for volume of fire.

Not by the early 30s any more. As far as I can tell MTB weren't a thing in the inter war years. DD were seen as the ones launching fish.

 

 

The Reichsmarine interest in the Schnellboot  dated from 1929, about five years before the 3.7cm SK C/30 went into service.  I would be fair to think that any navy with MTB type vessels would assume its enemies would also acquire these and that a defence would be required against them.


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#896 Markus Becker

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Posted 21 August 2019 - 0158 AM

That interest might have been the result of the ToV. Other navies didn't have to deal with such limitations.
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#897 DougRichards

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Posted 21 August 2019 - 1647 PM

That interest might have been the result of the ToV. Other navies didn't have to deal with such limitations.

 

The Soviets had the G5 MTB in service by 1934.


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#898 Yama

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Posted 22 August 2019 - 0844 AM

Most major navies twiddled with MTB's between WW1 and 2. They were in vogue somewhat intermittently, not everyone was convinced they were good use of resources, although in the end they were proven to be.
37mm guns tended to be too small against MTB threat, although this too uses benefit of hindsight.
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#899 Ken Estes

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Posted 22 August 2019 - 1049 AM

USN MTBs [PT boats} at the Cape Gloucester Campaign found themselves outgunned by the Japanese landing craft reapplying their garrison troops. The solution turned out to be USMC light and medium tanks in LCM-3 craft.

 

For the RN, their answer to th S-boote was the MGB, motor gunboat

 

 

 

File:Mgb_606_FL15328.jpg

 

 

 

File:Molins_autoloader_and_6-pounder_gun


Edited by Ken Estes, 22 August 2019 - 1059 AM.

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#900 JWB

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Posted 22 August 2019 - 1245 PM

Molins_autoloader_and_6-pounder_gun_WWII


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