Deck Gun Rate-of-Fire
 

I've been poking around the net after trying both the RFB and TM mods to find some info on the rates-of-fire of deckguns. I found some here on the US 5" 25-caliber gun mounted late in the war on the USS Bowfin.
http://216.239.51.104/search?q=cache...lnk&cd=1&gl=us
The stated ROF is ten rounds per minute! For those of you who are math challenged, that's one round every six seconds. So I'd say that TM is closer to reality in that aspect than RFB.

Admittedly, that's probably under optimal conditions.

Horst.

Stock SH4 has the reload time set to 4 seconds.

Note that the navweaps site lists the ROF for that weapon as 15-20 rpm. Poor Bowfin didn't read the manual, or they would have fired faster I guess ;)

So 66-100% lower ROF than spec, probably due to the poor platform a submarine is for a gun, ammo issues, and everythign being soaking wet all the time.

I'm actually perfectly happy with ROFs being in the ballpark of what that Bowfin site claims as long as the guns aren't gyro-stabilized death rays. Firing for effect, lying to in a calm sea, that would be fine as long as a boat making flank into a stiff sea can't do the same. Kv29's mod looks like it will absolutely mitigate this problem and allow a more accurate ROF to be in game while preserving historical outcomes.

That said, if the real ROF was 10 (assuming plenty of ready ammo), I'd tend to drop it by some small % to cover problems still not able to be modded in. So maybe 8-9 rpm for a 10rpm gun (jams/misfire clearing, etc).

Not that in my testing of kv29's mod, I was lucky to shoot at ~8 rpm at close range with the reload time set to 4 seconds just because of the roll and pitch of the boat.

Yes, this has been posted in every one of the RFB threads, proving that the gun can be fired that fast in testing. You need to read some of those threads to see some of the problems involved and exactly why Beery uses the rate of fire he does. We've been having this same discussion with these same "proofs" since the creation of RUB two years ago.

^^^ that said, kv29 is adding an entirely new capability to make more realistic guns without having to resort to the much lower ROFs required to get historical results with gyro-guns.

The debate will certainly continue, but the ability to solve it in SH4 just got considerably more complex (in a good way).

BTW, Berry has never appeared dogmatic about any particular ROF, just that it provides accurate simulation of RL use. Simulation is not just a count of rpm, but also the results, total times of engagement, etc.

tater

What is sometmes overlooked (and I don't think one could reproduce it in SH4) is that it wouldn't only be the deck gun used in the engagement but all other guns would be brought to bear as well - such as mentioned below. I read somewhere else that this was also standard practice for US subs as well. The AA going off as well keeps the buggers heads down while allowing your own gunners to get on with the job without worrying too much about return fire - which would help them in their ROF.









"Due to the high rolling and pitching, a U-boat makes a poor gun platform. Furthermore, depending on wind and sea conditions, it was not always possible to man the deck guns. The U-boat’s deck gun was also of no use against enemy warships, as enemy destroyers would easily outgun a U-boat anytime.

U-boat crew shells a British tanker after it failed to go down with a torpedo. Although intended primarily as a defensive weapon, the deck gun however could be used against stragglers and unescorted merchants, and some ships, particularly tankers could be sunk at leisure, even in daylight. It was also useful in conserving the limited torpedo supply and to finish off the kill of a ship crippled by a torpedo. Later in the war, merchants were armed with makeshift guns to repel deck gun attacks by U-boats. It was still possible to attack armed merchants however, as these were frequently manned by civilians with little or no training on naval engagements.
When the deck gun was used, the gun crew had to be secured by life lines to prevent them from being washed overboard. A crew of three manned the deck gun, gunner, layer and loader. For the ammunition, a chain of men had to be setup to bring the rounds from below the deck, to the conning tower and onto the gun crew. A small watertight locker stowed near the gun held a few more rounds ready for use, providing an advantage during the first few vital seconds of engagements. This also meant that crash dives took longer than usual, as the gun had to be secured and crew rushed below deck. There were no range finders, so engagements had to be done at close range. With an experienced crew, the rate of fire was between 15 to 18 rounds per minute. Three types of ammunition could be fired; armor piercing, high explosive and star burst (flare).
In a gunnery duel, the best position for the U-boat is to be at the stern of the victim, at a distance not less than 4,000 meters. An advantage is gained from the rear because the port side guns of the victim cannot be used in retaliation and only the stern guns can be fired. Point the boat towards the target. This presents a smaller target to the enemy, and keeping the bow pointed minimizes the effects of roll and pitch which would undermine accuracy.
Lay alternate fire with the U-boat’s other weapons in order suppress return fire. There is a four second interval between rounds, and while the deck gun is reloaded, open fire with a short burst of anti-aircraft rounds. If within range, small arms fire from the MG34 is very effective at suppressing return fire. Suppressive fire from the 20mm and even the 37mm anti-aircraft cannon will not sink the ship, but is used only to prevent the crews from firing back.
An attack could be aimed at the target’s bridge, waterline or weapon systems. Attacking the bridge will hinder the victim’s steering ability, while attacking at the hull’s waterline would quickly sink the ship. Attacks at the bows or stern will sink the ship faster compared to attacks on an even keel. Attacking the weapon’s systems will hinder the victim’s ability to fire back, but it takes just one unlucky shell to penetrate the U-boat’s hull which will make diving impossible. Armor piercing shells are better suited to hull attacks, while high explosive could be used against other targets.
The standard procedure for opening fire is to aim at the bridge and superstructures with ten rounds of incendiary shells, in order to provide a good marking point from the resulting fire, especially during night or low visibility conditions. The 37mm anti-aircraft cannon and MG34 is fired to suppress enemy resistance. The 20mm anti-aircraft cannon is kept in readiness, and fired only on orders from the commander. Typically, it will be used when there is a jam (stoppage) in the 37mm gun or when enemy resistance is too strong.
While it is better and safer to conduct a submerged torpedo attack, sometimes a U-boat may find itself out of position for a torpedo attack. If a merchant sails at 8 knots and above, and since the maximum underwater speed of a Type VII is also 8 knots, a U-boat had to surface to run its powerful diesel engines in order to catch up with its prey. Without the element of surprise, the deck gun makes a viable alternative.
Throughout the entire engagement, the watch crew are prohibited from witnessing the attack sequence. Four watch crews are on deck, with each covering a 90 degrees arc and they had to strictly scan their respective zones for any activity. They are not allowed to watch the attack to prevent the U-boat from being surprised by a lurking enemy."

Good lord.

We already had a thread 4 pages deep discussing this.

Another thread with a poll discussing this.

Now we have ANOTHER thread on the topic :oops:

Yes, you are right. but hopefully this thread will remain on the question: "How important was the use of the deck gun in combat?, Was it used often? What was its ROF? etc, etc" without bringing you-know-whose-mod into the equation. Lets leave the hystirics out of this thread and hopefuly the prima donnas wont be encouraged to come on board.

To me this is one of the joys of this type of game, it broadens your knowledge historically if you take the time to read, debate, learn and absorb issues in RL that you are trying to emulate in a game. I know my reading of war patrols of sub crews has an impact on how I play the game.

The deck gun was not all that important.

It was not used that often.

The rate of fire was dependant on a whole host of variables.

I think that pretty much sums it up.

Initially, deck guns were considered by many to be an extraneous and dangerous piece of hardware for submarines at the beginning of the war. Principally, the reasoning was that a submarine is basically a poor platform for a deck gun. Owing to the fact that the vast majority of the sub fleet's war patrols within 500 miles of Japanese bases were conducted submerged, the value of the deck gun was severely questioned. Additionally, it was reasoned that a submarine in a head to head gun battle with an enemy in possession of equal (or greater) firepower was at serious risk. Any enemy hits on the submarine which could impede or prevent her ability to submerge was justification enough to avoid a surface gun action. That's not to say that submariners didn't take advantage of some welcomed target practice when the opportunity arose. US Submarines that were scouting the Japanese Empire waters frequently came upon sampans, which were often suspected of being naval lookouts or anti-submarine pickets. By April of 1942, submarine skippers decided to start thinning out the sampan fleet and a periscope contact often resulted in the order of "Battle Surface". The results of a piboat going up against a lightly armed, floating bundle of wood one would think could be easily determined, however sinking these pesky little vessels was not a simple as first thought. Theodore Roscoe, in his book US SUBMARINE OPERATIONS IN WW II, states: "They could be riddled with .30 and .50 caliber machine gun bullets and holed several times by 3 or 5 inch shells and remain afloat like a box of Swiss cheese". More often than not, a submarine's deck gun was of greater value for overall morale than it was for combat effectiveness. A submerged boat that was damaged by an enemy surface vessel could, as a last ditch effort to survive, surface and engage in a gun battle, although with the odds generally stacked heavily against it. The deck gun was the ultimate weapon of last resort and it has been suggested that the 3, 4 or 5 inch guns (used for both anti-aircraft and surface actions and typically located abaft of the the conning tower), was therefore justified.
The 4 inch 50 caliber dual purpose cannon was standard issue to many submarines during World War II. This weapon had a muzzle velocity of 2,700 feet per second, a maximum range of 14,600 yards and was equally effective being utilized against both surface and aerial targets.
The US Navy's largest machine gun, and the one which was frequently found in a submarine's armory, was the Bofars designed 40mm; an automatic, rapid firing anti-aircraft gun, capable of delivering 160 rounds per minute at a maximum range of 2,800 yards - although its most effective range actually depended upon the type of ammunition used. Typically located forward of the conning tower, it often replaced two 20 mm AA guns.
While the single 40mm was air cooled and manually loaded, aimed and fired, both the twin and quad (double and quadruple barreled) guns were water cooled and was capable of firing by either manual, local power or by director power fire control. While not used on submarines, these weapons were designed for the larger warships (destroyers, cruisers etc)
The 20mm Oerlikon is a manually operated weapon and was located either forward or aft of the conning tower on the bridge deck. Fleet submarines often substituted twin 20mm guns for the single mounts for added firepower. Capable of firing 450 rounds per minute, the 20mm had a maximum range of 4,000 yards. The close range Oerlikin was an air cooled automatic anti-aircraft gun which fired an explosive shell - including the "tracer" - which glowed as it traveled towards its target and indicated the direction of fire.

There's the rub. No sub in combat fired anywhere near optimal conditions. Plus, a ROF for a gun is not the same thing as a ROF for a gun mounted on a sub. The former is for the gun system ONLY, with no accounting for an ammo supply located yards away from the gun or for the stability (or otherwise) of the gun platform. Then there's the issue of the target - guns firing to test the maximum ROF are not firing at a target and there's no necessity of rangefinding or measuring the effect of fire. Actually there's a whole host of issues that make it a big mistake to assume that gun system ROF values apply to combat.

RFB is the only version of SH4 that uses actual in-combat ROF examples rather than examples of gun tests from a firing range.

In theory a gun can be fired very fast indeed, but not in practice. In theory a man can eat a hot dog in about 10 seconds, but in practice people don't eat hot dogs in 'eating tournament mode'. The situations are completely different.

Listed ratings for gun ROF simply don't apply to combat.

(yawn)

Impossible to explain it better.
The main factor for a fast or slow ROF is related to our own human possibilities in a determined enviroment.

I think this has been discussed before, but lets refresh it a bit. Lets imagine the worst scenario: the weather is bad (which is game modeled) and the gun swings a lot (which is NOW modeled) so the guy at the trigger has to wait for the right moment when the sight appears to be on the horizon line, the gun crew cannot bringing more ammo at a fast pace because the deck is wet and moving a lot and is being constantly washed by waves, and to make things even worst the enemy is firing at them with the same or more powerfull explosive shells... :doh: and what about the shells weight? how many 65 lbs shells would they be able to handle until they get really tired slowing everything down?

btw, all the crew seems to be almost immune to gun fire (really bad modeled, can we change that??)

The ROF is an average, just that.

That said, kv29, I think that the reload time can be dropped (from RFB average) with the addition of your mod. Not back to 4 seconds, but somewhere between that and the 23 seconds beery has been talking about. My guess is that it could drop to 10 seconds as a fair compromise for factors not modeled in game.

If I were to keep the 15rpm standard used in stock SH4, but with your mod, I'd make the deck gun not allow fire in lighter seas than stock SH4. Pretty much if water came over the deck, start over. That would grossly reduce the ROF, actually.

Anyway, with your mod, I think the reload time can certainly start approaching a much lower value. Note I keep saying reload time. That's because with the gun actually hard to aim, and shooting disallowed when water sweeps over the deck several feet deep, the actual ROF will plunge. In calm seas, lying to at close range, you might then be able to "fire for effect" pretty rapidly, but start moving in any kind of chop, and turn... no way, you'll be down to 2-3 rpm in no time.

That's the future!

tater

After LOTS of testing we´ll be able to achieve a new average. It will not be perfect, either way it will benefit the enemy in calm seas, or to us in rough ones.

Hehe, the deck guns that need a massive increase in ROF are those on the decks of SHIPS, IMO.

tater