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

[Megatherion]

Hello everybody! I am brand new to Silent Hunter 3 and 4, and I was wondering what the ss ammo for the deck gun is. I figured out HE- high explosive, AP- armour piercing, AA- anti aircraft, and I think SS is sub sonic, but I am not sure. Also, what are the differences between the ammo types, ie what does each do? Any help with this would be greatly appreciated.

[smcj]

Greetings and welcome,

The SS "Star Shell" (flare on a parachute) is used to illuminate a target at night to aid you with your deck gun after you switch back to high explosives.

Good luck!

[Draka]

SS is StarShell.

Standard ammo types:
HE - High Explosive - blast damage, good against crew and soft targets, but doesn't make holes (penetrate)
AP - Armor Piercing - used against hard targets, but only puts holes in it - no boom-boom
AA - Anti-Aircraft - like it says - time-fused with a small blast charge (FLAK)
SS - Star Shell - illumination used to light up a target at night or other low light conditions

There is a debate on exactly what each Uboat actually carried - out of approx 220 rds of 105mm on U 199 there were 40 AA rds - see crew interrogation here: http://www.uboatarchive.net/U-199INT.htm

[Sailor Steve]

WELCOME ABOARD!

Looks like they've got you covered.

[RoaldLarsen]

Originally Posted by Draka

SS is StarShell.

Standard ammo types:
HE - High Explosive - blast damage, good against crew and soft targets, but doesn't make holes (penetrate)
AP - Armor Piercing - used against hard targets, but only puts holes in it - no boom-boom
AA - Anti-Aircraft - like it says - time-fused with a small blast charge (FLAK)
SS - Star Shell - illumination used to light up a target at night or other low light conditions

There is a debate on exactly what each Uboat actually carried - out of approx 220 rds of 105mm on U 199 there were 40 AA rds - see crew interrogation here: http://www.uboatarchive.net/U-199INT.htm

Those are the four type of ammo modelled in the game engine. GWX only provides HE for the deck gun. There are documented instances of U-boats using each of those four types of deck-gun ammunition in action, as well as two other types: semi-armour-piercing (SAP) and incendiary.

It is clear that the type and amount of deck gun ammunition carried on u-boats varied with date and circumstances (for instance AA ammunition seems to be more prevalent in 1943). I have not been able to find any clear references that show who was responsible for choosing which ammunition a u-boat carried. There is some indication that the u-boat's commander could at least influence the ammunication allocation.

HE ammunition could and did penetrate thin non-armoured plates, which is what almost all ships in the game (except battlehips and wooden vessels) are made of.

[Sailor Steve]

To add to the above, the so-called AP ammunition for shells this small was actually a Semi-Armor Piercing that would not penetrate the armor of even a light cruiser. The accepted standard was that this type of shell would penetrate approximately half of its own diameter, so a 4" shell could be expected to get through 2" of dedicated armor plate. Destroyers carried no armor, and the average merchant hull plating was less than 1/2" thick, so it was not really needed.

Of course the game reflects none of this.

While some boats were found to carry a variety of ammunition Campbell in his Naval Weapons of World War Two indicates that with the exception of the HE most other types were designated for surface ships. Carrying AA might be particularly useless simply because the deck guns could not elevate beyond 30 degrees. This would make them effective only against very low-flying aircraft.

[RoaldLarsen]

And the debate continues...

Campbell may indeed state this, but the proportion of primary source documents that indicate the use of non-HE ammunition by u-boat deck guns makes me question the value of his statement. HE was probably by far the most commonly used type of ammunition for u-boat deck guns, but it most certainly was not the only type of ammunition actually used by u-boat deck guns. I think that the historical record shows the use of multiple deck gun ammuntion types to have occurred so frequently that it is wrong to provide only one type of ammunition in the simulation.

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. 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.

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.

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.

[Draka]

I simplified the designation quite a bit - I wanted the basics to be clear to the OP. As for HE vs AP, HE has an impact fuse and thus though it may cause a hole by the blast, it was not designed for such. AP was designed to make a hole as a primary purpose. This of course is very simplified - there are HE rounds with shaped charges, delayed fuze types of APC with secondary HE charges, etc - I really was trying to be basic and relate to in-game uses.

[FIREWALL]

I would like to see incendiary shells modded in.

And Welcome Aboard.

[RoaldLarsen]

Originally Posted by Draka

I simplified the designation quite a bit - I wanted the basics to be clear to the OP. As for HE vs AP, HE has an impact fuse and thus though it may cause a hole by the blast, it was not designed for such. AP was designed to make a hole as a primary purpose. This of course is very simplified - there are HE rounds with shaped charges, delayed fuze types of APC with secondary HE charges, etc - I really was trying to be basic and relate to in-game uses.

Agreed that HE have impact fuses and are therefore designed to explode as a result of impact.

Agreed that AP is designed to penetrate.

What I am disagreeing with is two statements:

HE - High Explosive - blast damage, good against crew and soft targets, but doesn't make holes (penetrate)

and

HE has an impact fuse and thus though it may cause a hole by the blast, it was not designed for such.

HE shells are intended to punch a hole and AP shells are intended to explode.

I may be wrong, but it is my understanding that the history of the develpment of naval ammunition goes something like this:

In the beginning there was shot: solid round cannonballs fired singly, or smaller shot fired in clusters(cannister and grapeshot) or non-ballistic shaped shot for damage to sails and rigging (chain). This was fired from a smooth-bore cannon. This was countered by iron cladding. This in turn was countered by a ballistically shaped ammunition fired from a rifled barrel and designed to penetrate iron cladding by virue of a much higher terminal velocity owing in part to its ballistic shape. Roughly at the same time as the development of rifled naval guns came the development of fuzed explosive ammunition. Earliest fuzes were time fuzes, but these were largely replaced by impact fuzes.

The purpose of this explosive ammunition was not to create a hole by means of explosion rather than impact, but rather to cause greater damage after impact. The shell would punch a hole in the cladding due to its mass and velocity, and then explode on the inside of the target. Both early rifled shot and explosive shell had similar ballistic properties and similar penetrative properties on impact. In practice, solid baliistic shot was rarely used, except in small calibre guns.

Rifled naval guns were countered by armour. This was specially forged or milled steel that was much harder than the iron cladding of early metal warhips and also much harder than the metal out of which merchant ships and smaller warships of the WWII era were made. The ammunition designed to defeat armour was AP. It differed from previous ammunition by having its point hardened or capped with a hard material and the case strengthened. In some cases it would also have a soft outer cap applied to improve ballistic properties so as to increase terminal velocity or improve accuracy. Again, most armour-piercing ammunition was a shell that contained an explosive charge and an impact fuse. Because of the need for a stronger case and a more complex tip, the explosive charge was smaller than in a simple explosive shell.

So, the difference between HE and AP shells was not that the HE was designed to go boom and the AP was designed to punch a hole. Both shells went boom and both shells punched holes. The difference was that the AP shell was designed to punch holes through harder surfaces than the HE. The design features that enabled this result in a smaller boom. HE was a simpler, cheaper shell that would go through the hulls or superstructures of most ships and then explode. AP was modified HE intended to defeat armour.

Naval HE shells were not designed to create a hole soley as a result of the explosion on impact. Do not confuse HE shells with shaped-charge anti tank ammunition such as HEAT (High Explosive Anti-Tank). Those wepons used the force of a directed explosion to defeat armour, rather than the kinetic energy of impact. To the best of my knowledge, nobody deployed naval ammunition in WWII designed to defeat armour through the force of an explosion.

[FIREWALL]

My simple take on ammo is.

AP for Warships with thicker armor on beltline of hull.

HE for thinner merchant hulls.

Incendiary for Tankers.

3 things of importance are, Availability, Year, and Deck gun size.

[Megatherion]

Boy, this forum is great, one day and I get all of these answers and explanations! Of course, when I went and played SH3 again, I saw that the ammo was named star shell when I moused over the icon in the deck gun station and looked it up on the internet for an explanation-basically a flare. I was looking at the weapons management screen before, where the ammo was just named SS. Thanks again all of you for your quick replys and excellent descriptions and advice about all the ammo. Now I am going to start a new post about the damned insert waypoint function, all cntrl+left click does for me is center my u-boat to the middle of the map.

[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.