RAMMING SPEED!

[Chickenboy]

Just out of curiosity, I was wondering if AE is coded to account for intentional rammings. IRL, this was a not unheard method of dealing with submarines that had been forced to surface or last ditch efforts to inflict damage on a superior surface combatant (e.g., Glowworm vs. Admiral Hipper).

Thoughts?

[herwin]

ORIGINAL: Chickenboy

Just out of curiosity, I was wondering if AE is coded to account for intentional rammings. IRL, this was a not unheard method of dealing with submarines that had been forced to surface or last ditch efforts to inflict damage on a superior surface combatant (e.g., Glowworm vs. Admiral Hipper).

Thoughts?

This was the preferred way of sinking a surfaced sub, since 5" shells wouldn't penetrate.

[John Lansford]

Oh nonsense, Herwin.  Ramming a sub was considered a last resort for anything DD sized or smaller, since serious hull damage could be inflicted on the ramming ship as well as the sub.  A 5" shell was more than capable of penetrating a sub's hull as well, considering the huge number of subs sunk by that sized shellfire.

[herwin]

ORIGINAL: John Lansford

Oh nonsense, Herwin.  Ramming a sub was considered a last resort for anything DD sized or smaller, since serious hull damage could be inflicted on the ramming ship as well as the sub.  A 5" shell was more than capable of penetrating a sub's hull as well, considering the huge number of subs sunk by that sized shellfire.

See D. K. Brown, Nelson to Vanguard, 2006, where he discusses this. Yes, it produced serious hull damage, but no RN destroyer gun could penetrate the hull of a German U-boat.

[JWE]

From June ’43 to June ’44, 2nd Support Group sank 23 U-boats, 6 by gunfire, none by ramming. One of the 7 was sunk by DD gunfire, the remaining 6 were sunk by 4” gunfire from Sloops.

[anarchyintheuk]

The RN had a hodgepodge of dd weapons from a 4", two different 4.5s" and a 4.7". Always wondered why they didn't settle on one.

[JWE]

ORIGINAL: anarchyintheuk
The RN had a hodgepodge of dd weapons from a 4", two different 4.5s" and a 4.7". Always wondered why they didn't settle on one.

Beat's heck out of me. Our Brit OOBeings gave me the impression that the QF 4.7" was the standard battery piece for A-Class on, till the QF 4.5" HA was developed. Oh, well ...

Found some neat stuff on the QF 4.7". According to Scott Sorenson, your typical u-boat pressure hull was from about 18mm to about 21mm (some say up to 28mm). Your 4.7”, shootin SAP, could penetrate about 76mm (normal incidence) at about 6,000 meters. Not quite a hot knife thru soft butter, but not a bad gun. Could probably do the deed quite nicely even at engagement ranges of 7-9,000 meters.

[JWE]

Hi anarchy. Been looking, and found that just about any naval rifle, including the short 3”, had quite sufficient muzzle velocity, and were provided with appropriate ammunition (SAP and the like), to routinely penetrate a submarine pressure hull at all nominal engagement ranges. Even merchant ship armament was quite sufficient in this regard.

Just about all naval vessel load-outs were mostly SAP, with some small % HE early, and then, when AA got important, up to 40% AA, depending on warship mission. An AA shell wouldn’t do it because its primary burn is deflagration, but HE certainly could. The detonation front would stress the pre-stressed hull material locally. Bad news, not to mention spall. I’ll bet that there were way more subs that should be counted in the gunfire column; you know, get whacked, dive, implode, and who’s to know.

Yeah, basically, you got a naval gun, you can sink a sub.

[fbs]

ORIGINAL: anarchyintheuk

The RN had a hodgepodge of dd weapons from a 4", two different 4.5s" and a 4.7". Always wondered why they didn't settle on one.

I guess the same reason why they had a hodgepodge of tanks... lack of planning before the start of the war, and when shooting started they continued to produce what they had available, as a mish-mash was better than nothing.

They also seemed to have a lot of different aircrafts for bombing and patrol too...


Cheers
fbs

[herwin]

ORIGINAL: JWE

From June ’43 to June ’44, 2nd Support Group sank 23 U-boats, 6 by gunfire, none by ramming. One of the 7 was sunk by DD gunfire, the remaining 6 were sunk by 4” gunfire from Sloops.

DK Brown (2000) Nelson to Vanguard. Chatham Publishing. p 129: "It proved very difficult to sink a surfaced submarine as the shells would usually bounce off the rounded pressure hull. Ramming was more certain, and by May 1943 some twenty-four U-boats had been sunk in this way. However, damage to the escort would typically mean 7-8 weeks in dock and ramming was discouraged as shallow-setting depth charges became available."

[JWE]

Perhaps Mr. Brown did indeed say that in his book. There are a lot of books that say lots of things, or a lot people saying that books say a lot of things. But this idea that naval shells bounce off pressure hulls suggest a certain amount of rectal cranial infarction going on.

Anyony who took even the basic course at Ft Sill recorgizes the absurdity of that statement. Probably a good time to graciously quit.

[Panther Bait]

Re: Shells hitting subs.  It's probably not a pure penetration issue so much as a deflection/ricochet issue.  Much of what you see above the surface on a WWII sub is not the pressure hull, it's fairings for better seakeeping on the surface and the bridge/sail, and holes in the fairings/sail aren't going to sink a sub most likely.  Assuming the top of the actual pressure hull is rounded, shots may glance off the round surface rather than penetrating, despite the fact that the gun and SAP shell have more than enough penetration to go through a flat plate of similar thickness as the sub's hull.  It probably depended a lot on range, plunging fire would probably penetrate, but a sub is a pretty small target at those ranges.  Flat trajectory fire would be tough unless you could get waterline hits where the shot angles are more perpendicular.
 
Now, I have no idea how a deflected hit from a 5" shell may or may not compromise the pressure strength of the pressure hull.  Maybe it creates a weak spot, maybe not.  I also have no idea on the relative frequency of ramming versus kill by shellfire.  I just wanted to dispell any notions of 5" shells rebounding or shattering on a sub due to some super-tough quality of the sub's hull. 

[Barb]

Flat trajectory, high seas, rounded pressure hull on top, could ricochet some rounds.

[JWE]

ORIGINAL: Panther Bait
I just wanted to dispell any notions of 5" shells rebounding or shattering on a sub due to some super-tough quality of the sub's hull. 

Quite right. All naval rifles, down to 4", 3" and certain high velocity 2", were able to easily penetrate submarine pressure hulls at nominal engagement ranges. Period.

[herwin]

ORIGINAL: JWE

Perhaps Mr. Brown did indeed say that in his book. There are a lot of books that say lots of things, or a lot people saying that books say a lot of things. But this idea that naval shells bounce off pressure hulls suggest a certain amount of rectal cranial infarction going on.

He retired as Deputy Chief Naval Architect of the Royal Corps of Naval Constructors in 1988 and has been Vice President of the Royal Institution of Naval Architects. He had some 130+ articles in the field before he died last year. He also mentions that a special 4" shell for attacking surfaced U-boats, "Shark", was entering service as the war ended. It weighed 96 lbs. He wrote Atlantic Escorts: Allied Anti-submarine Vessels, 1939-1945.

The problem was not the thickness of the pressure hull per se, but the very high obliquity that the shells hit it at. We are talking about crush depths of 200-300 meters.

[JWE]

I don't care if he's the Archangel Gabriel. To any decent artillerist, a gun is a gun, and obliquity is something we know about more than most. Who gives a crap about crush depth. Hull thickness was 21mm (some say 28mm). Kinetics is kinetics and no amount of smoke and mirrors changes that. I know, because we studied fiziks at gun skool. We learned about penny-trashun makaniks, detonation velocities, and other kool stuff like that. It was a real eye popper to me because I was just a dumbass physicist from MIT, and these were real people, shooting real rounds, from real tubes, at real targets, in real engagements. golly gee willikers it was like a jumpin frog on a hot rock.

[sadja]

Water can cause shells to ricochet, also shatter high velocity rds. Your right 28mm shouldn't stop anything mounted on combat ships, but water will cause esp high velocity rounds to ricochet.

[witpqs]

What is the 'S' in SAP? [Assuming the AP = Armor Piercing.]

[Zebedee]

ORIGINAL: JWE

From June ’43 to June ’44, 2nd Support Group sank 23 U-boats, 6 by gunfire, none by ramming. One of the 7 was sunk by DD gunfire, the remaining 6 were sunk by 4” gunfire from Sloops.

Are you sure that's correct JWE? 2nd Support Group only claimed 16 in that time period, with 6 or 7 more coming from July 1944 til the end of the war. Of those 16, U-119 was by depth charges and ramming, and of the u-boats given as kills to the group in that time period only 2 involve gunfire - Starling 'sinking' one with depth charges and gun fire (U-202 - forced to the surface with depth charges and gunfire actually damaging the conning tower and then the u-boat was either sunk with depth charges while it was on the surface or was scuttled as the crew abandoned ship) and as for what happened with U-462, who knows, but the Germans were adamant that they had abandoned ship due to the damage caused by the Halifax several minutes before shellfire from the sloops started to appear around the already sinking u-boat. All the other U-boats were destroyed by depth charges, as far as I can tell. (I may know nowt about guns but your numbers have confused me ).

Oddly enough Donald Macintyre reported problems similar to those herwin states. The 3" gun on his frigates seemed to have difficulty sinking u-boats.

I'm sure there's a very good technical explanation for why the RN was not sinking many u-boats with gunfire on the surface, even when the u-boat was unable to submerge. The eyewitness accounts were that shells (however ridiculous it may sound) were bouncing off the u-boat hulls (3" and 4" shells). I appreciate that it sounds crazy but that is the evidence of one of the foremost RN ASW experts from the war. I'd truly appreciate any elucidation on what may have been causing such an effect.

With the utmost respect,

Zeb

[John 3rd]

When I think of Epic Ship vs. SS Actions in WWII, I cannot help but remember the New Zealand (or was it Aussie) ship that rammed a Japanese I-Boat off of Guadalcanal not once, not twice, but THREE times??!!  What a great story!