Battleship gun barrel life

[Curtis Lemay]

I seem to recall that the Yamato's gun barrels were only good for about 100-200 rounds, after which they would have had to be replaced. I can't find or remember where I read or heard this, perhaps the History Channel. Can anyone confirm this or tell me I'm nuts? If confirmed did it extrapolate to all battleships?

[Nikademus]

no. Barrel life depends on a number of factors but one of the most important would be muzzle velocity. Higher velocities will tend to wear out the barrel and liners more quickly than lower velocity.

On the extreme end of the scale, the ultra-high velocity 15inch guns of the Italian Littorio class only had a life of approximately 90 rounds....the price paid for being the most powerful 15inch gun produced. (in terms of penetrative power)

[Feinder]

There was a similar discussion on the boards, regarding the barrles of the Iowa class BBs (and so safely said, that the barrels of -all- warships come with an expiration date). The discussion naturally led to "this should be simulated in WitP!". Kind of an over-complication of things. Ships take sys damage from simply moving from point a, to point b. This represents a lot of wear and tear on the ship, that just isn't the engines. Furthermore, ships did have extra barrels available to them, and it's a safe assumption that a ship would be replacing barrels (if necessary) when you click "Resupply". You're not just getting more bullets, you're taking on fuel (if available), fresh water, several tonnes of powdered eggs, and gun barrels. (True, you wouldn't be able to get 16" gun barrels at small anchorage, but again it's splitting hairs).

My personal take on it is, the fundamanental problem with naval ops is the quick turn-around of a task force. Whether you're talking about replacing gun-barrels, taking on 6,000 tonnes of explosives, or loading a 6 months supply of powdered eggs; only 24 hours (one turn) to get underway, is "ambitious" to be very polite (if not delusional).

I've thought it would slow things down, if that's what the players want (and I don't think they really do), if you gave each port DockPoints that are expended as you create TFs. The larger the ship, the larger the DockPoints required to make ready to get underway. A port would generate DockPoints per turn, equal to 100 x PortSize (or maybe more, depending on balancing). PortPoints are not "banked" and are simply generated/spent/lost each turn. Getting a PT boat ready to get under way, might only take 10 DockPoints. Whereas a DD might take 100, and a BB might take 500 and CV 700 (just throwing numbers out). Basically, that means that you're not going to be able to dock a BB at anything less than a size 5 port, in order to reprovision (fully). You could easily operate a small flotilla of PTs from a size one port (you could rearm 10 per turn). But an ASW TF with 4 DDs pulls up to your size 1 port, (a DD is the largest size serviceable), it's going to take all of your efforts to rearm/reprovision/"rebarrel" just a single DD. It's going take you 4 days to add them all of the DDs in your TF.

Again, it's constraining the larger ships to reprovisioning at the larger ports.

But I also know that would be MAJOR, MAJOR, MAJOR change. And certainly, if I were Matrix, I'd politely tell me to "bugger off"... :^)

Conversely, be careful what you ask for.

While players are happy to nit-pick for realism, "realism" means slowing the pace of things down, a LOT. Players like sending their CVs hunting everything in sight. But if you could (more realistly) deploy your CVs for 4 weeks, and then they sit in port for another 4 weeks, players would likely scream bloody he11. Matrix has given us a bunch base-ball bats that never crack and said, "Ok! You've got 1500 turns to beat the crap out of each other! Go to it!" If things were done to dramatically slow the pace of the game (making it much more realistic), you'd have players screaming "NERF!" or worse.

-F-

[Skyros]

If you had the barrel, how long would it take to change it? It seems that a good ized crane would be needed for this operation.

[Mike Scholl]

ORIGINAL: Skyros

If you had the barrel, how long would it take to change it? It seems that a good ized crane would be needed for this operation.

You don't change the barrel..., you replace the barrel liner.

[Nikademus]

early war....if requring a complete barrell change (such as when Pennsylvania had her guns replaced using spares salvaged from Oklahoma) the ship would need to return to a major port.

Late war USN, I believe IIRC that they actually could transport the barrels to their mobile bases that utilized atolls.

[PeteG662]

As an artilleryman, I will tell you that you have to do major renovations to the barrel. The wear and tear on the lands and grooves inside the barrel (rifling) caused by the round passing through as well as the gasses eating at the metal creates the need for barrel replacement. Current US artillery tubes have checks every 500 EFC (equivalent full charges) and are replaced by Watervliet Arsenal in NY when detection of excessive wear on the lands and grooves, stress cracks, warping or metal fatigue from gas occur. The check done is called a Borescope and Pullover. There are certain standards that have to be met or the tube is sent back to the depot for retooling or replacement whichever is required.

The simple answer is the tube does get replaced at some point, however it depends on many factors. The technology and solutions in the 40s was not as sophisticated as today in handling this problem.

[hithere]

i assume you mean field arty.....155? anyway...does field arty use liners like the naval guns?

[PeteG662]

there is no liner in smaller tubes as they are cast and bored. There is a coating to help with the gas issue if that is what is meant by a "liner". There is still major retrofit that has to be done to ANY tube after sufficient wear. It all boils down to the 'rifling' inside the tubes.

[Twotribes]

Lets not forget firing is abstracted in the game as well, I am afraid a BB had more than 9 shots per turret on board.

[juliet7bravo]

I recall being on the demo range using 8" gun barrels (complete) as scrap for steel cutting shots. Probably 50 brand new rifle barrels sitting there, dating from WW2. Doesn't the bunker buster bomb they developed (in a hurry) during Gulf#1 use a section of 8" naval gun barrel with a titanium nose cap as well? Obviously, they made alot of spare barrels.

[Tiornu]

The average barrel life for a BB-caliber gun is in the neighborhood of 250 rounds with a full-service charge of propellant. Japanese practice included three charge ratings: the full charge, the weakened charge (half a full charge), and the reduced charge (half a weakened charge). The weakened charge was used for bombardment missions, but I have no specific info on when the reduced charge was to be used (target practice?).
The Americans were unusual in specifying reduced charges for use against enemy heavy ships. The Iowas could derate to 2300fps from their usual 2500fps (and even lower, I believe) in order to maximize the incidence and effect of deck hits. The idea of enhancing a 2700-lb shell's deck performance is truly frightening.
Yamato's barrel life was 200-250 rounds. Bismarck's was 250. Scharnhorst, despite the meager 28cm caliber, had only 300. (Keep in mind, I cannot say that the various navies used identical definitions of barrel life.) As mentioned, Littorio was at the low end here, 110-130. All the British ships were over 300, except of course Nelson at 250. The top figure is for the American 16in/45 gun--395, regardless of the shell weight. As an aside, this matches the 350-400 rounds for one Japanese gun--the 100mm DP gun! (The US 5in/38 had 4600, and no, I didn't accidentally add an extra "0.")
It was US practice to replace the liners when the ship's loadout was equal to the anticipated remaining life of the barrels--so figure when the barrels had a hundred firings left. So barrel life is not likely to figure in a battle, though you have to think that Littorio would suffer greater round to round variation than SoDak.

[PeteG662]

That would go into the targeting routine and factor into whether there was a hit or miss in game terms after prolonged combat.....