What is ss deck gun ammo and what are the differences between the ammo types?

[Sailor Steve]

Originally Posted by RoaldLarsen

And the debate continues...

I didn't mean to start it up again. My intention in referencing Campbell was to show where the GWX changing of everything to HE came from. In fact Campbell's wording is vague, but at the time I originally brought it up it was what I had. When I read the later capture reports I was surprised, but not overly so. It's obvious that the captain had some leeway in the loadout he carried.

For me it is an open question whether there was a SAP ammunition that was distinct from the AP ammunition. I have certainly seen reference to both, but I am not certain that I have seen reference to both in the same document. It is possible that both terms were applied to the same ammunition. However, I do have the impression that the AP was solid shot, while the SAP had a small base-fused explosive charge.

That I do know a bit more about, from my experience with years of research for my own naval tabletop miniatures game.

When the British commissioned the Majestic class battleships in 1893, the loadout cosisted of "Armour-piercing solid shot, Armour-piercing shell, Semi-armour-piercing common, and dummy rounds", with no High explosive. The problem at that time was that no one was sure that an AP shell would even work. By the First World War the AP solid shot was gone, the loadout was mostly AP shell, along with some Common and HE. Common was for use against unarmored targets and HE was meant for shore bombardment.

Destroyer guns of the period had Common rounds and nothing else, and carried the wonderfully awkward designation of SAPCBC (Semi-Armour-Piercing Capped British Common).

In World War Two the famous US dual-purpose 5"/38 carried no HE, but a Common type called HC, for High-Capacity, which was designed to pierce the roof of a small concrete bunker, along with AA rounds, which was why they were 'dual-purpose'.

My copies are all in storage, so I can't give you specific issue numbers, but most of this comes from various issues of Conway's Warship magazine and the Amercan Warship International, including articles on the Majestic class battleships and HMS Bulwark, of the London class. They also contain Campbell's series 'British Naval Guns: 1880-1945.'

Another source I love is also by Campbell: Jutland - An Analysis Of The Fighting. It contains a shot-by-shot description of the battle - who fired what type of shell, where it hit and damage done. The best part is the information that one British battleship (I think it was Hercules) was loaded for a bombardment mission and went into the battle with nothing but HE!

I had understood that the distinction between the terms "AP" and "SAP" was design-based, not performance based. I can see little reason for the game to model these two types of ammunitions separately.

As I said, there is a big difference but I'm pretty sure that nobody ever made a true AP round for any gun smaller than 6", so your judgement stands. M. J. Whitley, in his book German Destroyers of World War Two, says that the actual German terms stood for 'Nose-fused HE' and 'Base-Fused HE', so I don't know if the German 'AP' (or 'SAP') round was actually capped at all, but rather was just an HE round with a base-mounted fuse to delay the explosion to guarantee full penetration of an unarmored hull before going off.

There is greater certainty that the incendiary was distinct from the HE. There are individual records indicating the use of both types of ammunition by a single gun in a single engagement. The damage model employed by the game would seem to give no reason for the game to model both types separately.

Probably true, but I'm not familiar with how the game models work so I'm not in a position to argue one way or the other.

The lack of a high maximum gun elevation did limit the usefulness of AA deck gun ammunition, but remember that most aircraft tended to attack submarines from a low altitude. U-boats are known to have engaged aircraft with their deck gun using AA ammunition.

Also true. The only story I heard of a u-boat shooting down a plane using its deck gun didn't say whether they even used an AA round. Pretty funny if they did it with a standard round!

[RoaldLarsen]

Originally Posted by Sailor Steve

I didn't mean to start it up again. My intention in referencing Campbell was to show where the GWX changing of everything to HE came from. In fact Campbell's wording is vague, but at the time I originally brought it up it was what I had. When I read the later capture reports I was surprised, but not overly so. It's obvious that the captain had some leeway in the loadout he carried.

And here my wording was vague too. What I should have made clearer was that I was talking about u-boat deck gun ammunition in particular. I do know that for other guns there was a distinction between AP and SAP. It was unclear to me as to whether there was AP ammunition used by u-boat deck guns that was distinct from SAP ammunition used by u-boat deck guns.

Originally Posted by Sailor Steve

As I said, there is a big difference but I'm pretty sure that nobody ever made a true AP round for any gun smaller than 6", so your judgement stands.

You seem to be saying here that there was no true AP round for u-boat deck guns, and therefore we can probably assume that in the context of the ammunition for these guns, we can take 'AP' and 'SAP' to mean the same shell.

This could very well be correct. It is not what I was assuming, but I have no solid evidence for my assumption that AP was solid shot (or possibly capped shell) and that SAP was (possibly uncapped) shell.

Originally Posted by Sailor Steve

M. J. Whitley, in his book German Destroyers of World War Two, says that the actual German terms stood for 'Nose-fused HE' and 'Base-Fused HE', so I don't know if the German 'AP' (or 'SAP') round was actually capped at all, but rather was just an HE round with a base-mounted fuse to delay the explosion to guarantee full penetration of an unarmored hull before going off.

We need to be careful here. The Germans indeed had terms for Base-fuzed HE and Nose-fuzed HE: 'Spr.Gr.Bdz' and 'Spr.Gr.Kz'. These stood for "Sprenggranate mit Bodenzuender" and "Sprenggranate mit Kopfzuender", literally "burst shell with bottom igniter" and "burst shell with head igniter". However the Germans had a separate term for a different class of naval ammunition: 'Psgr', which stood for 'Panzersprenggranate'. I am not sure whether this is better translated as "armour burst shell" meaning "explosive shell to use against armour", or "amoured burst shell" meaning "explosive shell that has been hardened". (When used as a prefix, 'panzer' is translated as either 'armour' or 'armoured', depending on context.) No matter which translation, it clearly is a term that corresponds to English 'AP' or possibly 'APC'.

While we are on the issue of terminology, I should state that it is my understanding that the Germans reserved the word 'haube', literally 'hood' or 'cap', for a ballistic cap. So a shell designated as Psgr.mHb' would correspond to 'APBC', and possibly 'APCBC' but not to 'APC'. I am unaware of the Germans using a term that corresponded literally to 'SAP' as a designation for any of their naval shells.

It is possible that what the Germans termed 'Psgr', and which we would therefore translate as 'AP' would be evaluated as equivalent in design or performance to British or American 'SAP'. Therefore English language references to the same shell could be either 'AP' or 'SAP' depending upon whether the reference was being made by a translator or an evaluator.

Because of this confusion of terminology, when reading Engish language documents, unless one sees a reference in the same document to use of both AP and SAP by a u-boat deck gun, we cannot know from those sources conclusively whether u-boat deck guns had both AP and separate SAP ammunition. I think we are most likely going to have to rely on German-language source documents about ammunition availability to resolve this question.

Sailor Steve, thanks for your ongoing contributions - first to GWX, and now to our improved understanding of u-boat deck gun ammunition.

[RoaldLarsen]

Originally Posted by Sailor Steve

Destroyer guns of the period had Common rounds and nothing else, and carried the wonderfully awkward designation of SAPCBC (Semi-Armour-Piercing Capped British Common).

Ah - a terminology ambiguity, wrt the 'BC' suffix. The later term APCBC stood for Armour-Piercing, Capped, Ballistic Cap.