RAMMING SPEED!

[JWE]

ORIGINAL: Zebedee
Are you sure that's correct JWE?
Zeb

Woops, yep, you’re a better data looker than me. Got excited and just counted. According to the final report by Commander Wemyss to the Admiralty, it was 17 confirmed from mid ’43 to mid ’44, with 6 more confirmed from mid ’44 to the end. 1 of those last 6 was gunfire.

Of the rest, Starling (Black Swan class sloop) got credit for 2 with guns alone, Wild Goose (Black Swan class sloop) got credit for 1 with guns alone. Kite (Black Swan class sloop) whacked one with guns and Woodcock (yet another Black Swan class sloop) dropped on the slick for the kill confirmation. Then another where Goose whacked one and Starling dropped on the debris field for the kill confirmation. And then there was a multi-ship group grope, where somebody (Kite claims it was her) opened up U-462 “like a tin of M&V”.

[Local Yokel]

Am I right in recalling that there were a number of cases in which merchant ships under submarine attack attempted to turn upon their tormentors by attempting to ram?  Did Richard O'Kane describe such an incident in his account of Tang's patrols?  Several thousand tons of merchant ship making a bee-line for my periscope with a bone in her teeth would certainly incline me towards breaking off an attack and going deep.

[Zebedee]

ORIGINAL: JWE

Woops, yep, you’re a better data looker than me. Got excited and just counted. According to the final report by Commander Wemyss to the Admiralty, it was 17 confirmed from mid ’43 to mid ’44, with 6 more confirmed from mid ’44 to the end. 1 of those last 6 was gunfire.

Of the rest, Starling (Black Swan class sloop) got credit for 2 with guns alone, Wild Goose (Black Swan class sloop) got credit for 1 with guns alone. Kite (Black Swan class sloop) whacked one with guns and Woodcock (yet another Black Swan class sloop) dropped on the slick for the kill confirmation. Then another where Goose whacked one and Starling dropped on the debris field for the kill confirmation. And then there was a multi-ship group grope, where somebody (Kite claims it was her) opened up U-462 “like a tin of M&V”.

Thanks JWE and many thanks for including a reference to your source. On the U-462 incident, perhaps a POW report would provide different light on the matter.. http://www.uboatarchive.net/U-462INT.htm

In U.462 the vents were opened and the Captain gave the order to abandon ship.

(N.I.D. Note: At 1216 the damaged U-boat came to a standstill and was seen settling slowly on an even keel, while a number of the crew were seen taking to dinghies. Just before the conning-tower, from which smoke was still emerging, finally disappeared, splashes were seen in the sea and sloops were sighted in the distance. No shells were seen to fall nearer than 500 yards from the U-boat, which disappeared ten to fifteen seconds after the shelling was first seen. Position of sinking was given as 45008'N, 010058'W.

The third U-boat dived and is believed subsequently to have been attacked with depth charges by H.M. Ships of 2nd Support Group and sunk at 1543 in position 45033'N., 010046W. There were no survivors.)

There's obviously a lot of discrepency between the primary sources

[Chickenboy]

So, to bring this discussion back on to track-the ramming track, that is-any ideas why this activity was not included as a last ditch attack in WiTP or AE? If we have accidental collisions between ships, surely this wouldn't be too hard to model?

[JWE]

ORIGINAL: Zebedee
There's obviously a lot of discrepency between the primary sources

Oh, yeah, you got that right. As to where the shells bouncing off comes from, who knows. I bet it’s War-I short barrel, low velocity, relics, where the gunners are trying to get the Ordnance peoples attention.

The modern 4”, used by those sloops, and lots of others, had a muzzle velocity of over 800 m/s shooting a ballistic capped SAP projectile of a bit over 17 kg. Your 4.7” also had a muzzle velocity of over 800 m/s shooting a ballistic capped SAP projectile of a bit over 22.5 kg. That’s actually better than the US M5 ATG shooting APCBC. Just think about it.

[Zebedee]

ORIGINAL: JWE
Oh, yeah, you got that right. As to where the shells bouncing off comes from, who knows. I bet it’s War-I short barrel, low velocity, relics, where the gunners are trying to get the Ordnance peoples attention.

The modern 4”, used by those sloops, and lots of others, had a muzzle velocity of over 800 m/s shooting a ballistic capped SAP projectile of a bit over 17 kg. Your 4.7” also had a muzzle velocity of over 800 m/s shooting a ballistic capped SAP projectile of a bit over 22.5 kg. That’s actually better than the US M5 ATG shooting APCBC. Just think about it.

That certainly makes a lot of sense to me and goes a long way to reconciling the differing views. What really surprised me is that the US coastguard was sinking u-boats with the very same gun that Macintyre's frigates were complaining were firing the bouncing shells (3"/50?). It does make you wonder what on earth was going on and whether ramming (which was actually a method of last resort in the Admiralty's book) was being 'excused' on the grounds of 'inadequate equipment' by certain commanders. Although it does have to be said that many works post-war do indicate very few u-boats were sunk by gunfire - on what grounds they come to that conclusion from the differing primary sources, well, who knows now?

It would be 'nice' to see ramming in the game - there is a lot of evidence for it being a 'solution' for close range encounters but I'm guessing the combat model does not allow for it (and wouldn't without a disproportionate amount of work) hence why it's not in the game?

[Mynok]

I have zero historical knowledge on the subject, but it seem totally logical to me that we have a DD depth charging a U-boat and driving it to the surface in close proximity. Gun depression issues come to bear and it seems prudent to the commander to run down the U-boat rather than try to hit the only target he has which is the conning tower.

But my brain works differently than you humans. [:D]

[Scott_USN]

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.

That was just funny for some reason. I think the Sloops won out... Nerf the Sloops!

[witpqs]

ORIGINAL: witpqs

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

Bump

[Fishbed]

SEMI-Armor Piercing

(that will be 5 bucks, got my paypal account right?)

[Chickenboy]

ORIGINAL: Scott_USN

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.

That was just funny for some reason. I think the Sloops won out... Nerf the Sloops!

[:D]

[herwin]

ORIGINAL: 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.

Well, terminal ballistics is not my speciality, but I had to know quite a bit about it 30 years ago. The armour penetration of a RN 4" naval gun firing AP was on the order of 100-130 mm against 30 degree obliquity armour. When you consider a submarine hull at 25 mm or so, that sounds pretty good. However at high obliquity, you have two factors to take into account--the shell tends to ricochet, and the steel to be penetrated is increased in proportion to the tangent of the obliquity. I don't have a copy of Ogorkewicz at hand, but I seem to recall the combination of both factors results in something like a reduction of 3-4 times in penetration when the shell hits at 60 degrees obliquity. Perhaps we can do a rough analysis. A submarine pressure hull is basically a length of sewer pipe made of high-quality steel armour plate floating very low in the water. Its cross-section is oval (at the ends) and circular (in the middle). For the U-VIIB, the diameter was about 4.7 meters, and the draught when surfaced was 4.4 meters, so we're talking about the pressure hull making a 60 degree angle at the surface of the water--that's rather high. It looks like the average angle at which the shells hit the pressure hull was about 15 degrees--i.e., the armour was at about 75 degrees obliquity. I don't think the shells will usually penetrate at that angle--they'll bounce off.

[Speedysteve]

ORIGINAL: JWE

I don't care if he's the Archangel Gabriel.

ROFL[:D]

[Monter_Trismegistos]

ORIGINAL: JWE

I don't care if he's the Archangel Gabriel.

But you should. He might came from heavens and sink your carriers with his sword.

[Sheytan]

LOL!

ORIGINAL: Monter_Trismegistos

ORIGINAL: JWE

I don't care if he's the Archangel Gabriel.

But you should. He might came from heavens and sink your carriers with his sword.

[witpqs]

ORIGINAL: Fishbed

SEMI-Armor Piercing

(that will be 5 bucks, got my paypal account right?)

Thanks. It's in the mail!

[bklooste]

Pressure hulls and subs were NOT armour plated thats a major difference a 4" could prob penetrate like 160mm-200mm of steel even quartered that's enough.

However it depends what you mean by surfaced !.. A Periscope depth "Surfaced" sub is much harder to kill as you have to add a few feet of water and have a narrow target . I think this is exactly what they mean because they refer to shallow depth depth charges. It makes even more sense when you think about it as the sub can torpedo a warship so turning to face the sub to Ram it would also make sense. Note Pacific subs were more likely to be on the surface.

rminal ballistics is not my speciality, but I had to know quite a bit about it 30 years ago. The armour penetration of a RN 4" naval gun firing AP was on the order of 100-130 mm against 30 degree obliquity armour. When you consider a submarine hull at 25 mm or so, that sounds pretty good. However at high obliquity, you have two factors to take into account--the shell tends to ricochet, and the steel to be penetrated is increased in proportion to the tangent of the obliquity. I don't have a copy of Ogorkewicz at hand, but I seem to recall the combination of both factors results in something like a reduction of 3-4 times in penetration when the shell hits at 60 degrees obliquity. Perhaps we can do a rough analysis. A submarine pressure hull is basically a length of sewer pipe made of high-quality steel armour plate floating very low in the water. Its cross-section is oval (at the ends) and circular (in the middle). For the U-VIIB, the diameter was about 4.7 meters, and the draught when surfaced was 4.4 meters, so we're talking about the pressure hull making a 60 degree angle at the surface of the water--that's rather high. It looks like the average angle at which the shells hit the pressure hull was about 15 degrees--i.e., the armour was at about 75 degrees obliquity. I don't think the shells will usually penetrate at that angle--they'll bounce off.

[Dili]

Pressure hulls and subs were NOT armour plated thats a major difference a 4" could prob penetrate like 160mm-200mm of steel even quartered that's enough.

If it bounces it doesn't matter how much it penetrates. A very heavy round at high velocity might shatter and dent the surface, but much of energy is diverted.

[jmbraat]

I always assumed that was a lot of critical equipment between the pressure hull and the outer hull such as ballast, pumps, and such. Am I wrong? If these were "compromised", surely the sub would be in trouble.

[John Lansford]

Were WWII subs double hulled?  I didn't think they were.  However, if a sub is using its deck gun at a merchant then I'd expect the merchant to fire back at the conning tower area, which would represent the largest target on the sub.  A hit there is most definitely not striking at an angle like it would on a rounded hull, and a 4"-5" gun would have enough penetration/explosive power to do some damage.