Replacing ship's main gun with 155mm artillery?

The thing is that most of the modern naval guns are DP guns with high rate of fire. Both these features cannot be achived with 155m guns orginally intended for field artillery role. 155m guns ammunitions haven't got shellcasing and the ammunition (piggie) is a separate particle and the gunpowder is in bags which you load after the ammunition is stucked to the tube. Most modern Naval guns however has a riflecartidge type of munitions with shellcases and all...

Dear Sirs:

If I remember correctly, traditional heavy naval guns (greater than 6 inch - 153 mm caliber) are typically bag-charged. The projectile was first loaded, then rammed, after which the required number of powder bags (looking rather like giant pillows) were then loaded into the chamber.

Ignition was usually electrical, and to aid this gunpowder charges were stitched onto the ends of the powder bags. Sealing the chamber (obturation) was done by a mushroom-shaped piston acting upon a seal ring. When the gun fired the high pressure would compress the ring, expanding it's circumference, sealing the chamber.

One of the limitations (aside from those mentioned in the articles posted) would be the rate of traverse and elevation - which are slower in a land system. Another would be the limited amount of elevation available. All this would limit the systems' usefullness against aerial or fast-moving targets, reducing its role as a dual-purpose gun.

Given enough power, I suppose the training rates could be increased, however, how much that could be improved for a piece of artillery like a 155 mm gun is debateable. That is a pretty heavy piece of metal to swing rapidly about.

If sustained fire is required, then typical naval modifications like water-cooling and air-purging must be made. Rapid replacement of the barrel would also be called for.

The kind of long-duration, maximum rate-of-fire bombardments undertaken by navies is unusual in land-based field artillery operations. Our own fire-missions (with ex-US WWII 105 mm howitzers) were seldom done at the gun's maximum fire-rate.

The resultant weapon would end up firing specialized guided ammunition for the majority of it's fire missions - land, sea or air. I foresee a tremendous increase in the cost of such ammunition - ending up with a piece that is more like a glorified missile launcher.

Would such a weapon ultimately justify the fanstastic increase in cost over conventional naval artillery with more modest technical improvements? I think not.

In the end, navies kept the gun because it was the most economical way to engage a wide variety of targets effectively - something that given the history of US guided projectile developement is unlikely to be achieved.

What is much more likely to happen is that the US Navy will once again find the most expensive way to arm its' ships with guns.

Best Regards,

Dusky Lim

Another point to remember is that modern Naval guns are quite different from land artillery pieces, inasmuch as they are fully automatic weapons operated from the CIC. Nobody is in the gun mount, indeed there is no room for anyone in the gun mount other than for maintenance. In the Falklands war the British 4.5inch (114mm) mk8 single and mk6 twin mounts were reckoned to achieve a rate and weight of fire comparable to a six gun land battery equipped with 105mm guns. The mk8 is a very reliable weapon having been in service for over thirty years, and the trend towards heavier guns has seen the mount proposed as the basis for a 155mm weapon for the new type 45 Daring class DDGs. It could also be retro fitted to any ship mounting the mk8 in theory, and as it was widely exported that could mean orders from abroad too.
The 155mm Naval gun would use essentially the same barrel as the army's gun, but would have to use rifle cartridge ammunition in order to be compatible with the auto loading system so a common supply of ammo with the army isn't possible.

Well, if you want to shoot down AC then its 5 inch or 120mm. If you want to sink ships its 6 inch or 150 mm. All durring WW2 the Allies were trying to get a good 6 inch AC gun. They never did it and still have not. Most people dont realize the big difference between a 5 inch and 6 inch shell. A 5 inch is about 80lbs and 6 inch is over 240lbs.
The Japanese tryd to shoot 18 inch anti AC shells out of the Yamato ( or sister ship- forgot name) and blew out it turrents- (reported, not confirmed).

This forum is unbiased and internationally friendly, so let's not use contractions that can result in misunderstanding.

Dear Sirs:

The representative projectile weights of a 6 inch weapon (about 155 mm) would range from 45 to 50 kilograms (thats about 90 to 100 lbs approximately). A 5 inch weapon (127 mm) would have about 25 kilogram round (about 50 to 55 lbs approximately).

Armour-piercing rounds would be heavier, while high-explosive rounds would be lighter. Of course to pierce ship armour at long range, the heaviest shell is the best one.

It its final series of WWII light cruisers, the Worcester class, the US Navy introduced what was the most potent of 6 inch naval weapons, the 47-caliber, Mk 16 Dual Purpose gun. Unfortunately these cruisers were too late to serve in the War.

It was an excellent weapon, capable of being loaded at all elevations! The new all-power turret could be trained and elevated more rapidly than any previous models. It was considered an excellent AA weapon, more effective than the previous 5-inch 38-caliber it replaced.

The round that the Japanese developed for firing against aircraft is called the san kai dan. It was a form of AA shrapnel. The 1.3 ton shell was filled with bomblets and was timed to burst about 1000 meters from the gun. Bad fuzes could set it off inside the barrel with terrible consequences.

Best Regards,

Dusky Lim

dusky
You are right on. I am going back and trying to find where I got my bad info on the web. Will do my best to give you a link- thanks for the correction.

Well, if this gun fails as a lone DP gun on a ship, then why would the US and Germany switch o the 155mm? (Or do you think it is a mistake?)

Looks like I was looking at the actual turrent and not the shell- my bad.

Data is for Bismark

Twin Mounts:
116.250 kg (256.287 lbs.) including range finder
110.000 kg (242.500 lbs.) without range finder
108.000 kg (238.100 lbs.) without range finder and short barbette

I have nothing against this idea but, what is the use for a gun? Guns on ships these days are litterally useless. Against enemy ships, you use torpedos. against land targets, you use cruise missiles. Features that every modern warship has.

Torbedos??? Every modern ship have them???...well lets see...hmm...Give me a minute.... Got it, haha...Latest Russian destroyers carry 533mm torbedoes...

...but those are for ASW operations

I hate being a pain-in-the-ass but perhaps little introducting to naval warfare comes at handy once again...

Dear Dennis:

The best source online for all naval gun info is the Naval Weapons site (www.NavWeaps.com), run by Nathan Okun and company. As far as I know it is the most comprehensive site for naval weapons in general and the best I've ever found regarding naval guns and armour in particular.

But when it comes to specifics (like in your example of the Bismark) individual sites may be more accurate.

Going back to topic, as Nathan Okun relates, the change over from the older 6-inch mount to the newer 6-inch mount caused a weight increase of 20 percent, and the higher rate of fire was accompanied by a loss in reliability.

This mount served as the prototype for the most successful big-gun mount in the US Navy the 8-inch mount on the Des Moines class heavy cruisers. In contrast to the 6-inch mount the 8-inch was one of the most reliable ever built and had 3 times the rate of fire of all previous 8-inch mounts to boot!

Of course this was obtained by a weight increase of 50 percent. So that must be the price one has to pay for the higher rate of fire and greater reliability.

With newer technology we definitely can increase both the rate of fire and training speed of a 155 mm piece, but I think experience will show that we will have to accept both greater weight and higher servo power in order to do so. Such a weapon could not be mounted on smaller combatant vessels.

Simply grafting a 155 mm gun-howitzer onto a ship (like the Germans did with the turret of a PZH-2000) will not create a dual-purpose weapon. One would have to take the land-based weapon as a basis and deliberately develop it into naval DP gun system.

The current US Mk-45 5-inch gun is a good example of a typical naval weapon. One in which (in contrast to European and Russian practice) the rate of fire was kept down (about 20 rpm) in order to maximise reliability and barrel life.

In operation the weapon is fully automatic and autonomous. The only crew needed are the guys who load the ammunition carousel below decks.

My fear is that the USN will lose sight of a cheap, simple weapons' (i.e. a naval gun) virtues and will spec and gold-plate the thing to death (super missile launcher).

Best Regards,

Dusky Lim

Originally Posted by Gollevainen

Torbedos??? Every modern ship have them???...well lets see...hmm...Give me a minute.... Got it, haha...Latest Russian destroyers carry 533mm torbedoes...

...but those are for ASW operations

I hate being a pain-in-the-ass but perhaps little introducting to naval warfare comes at handy once again...

Educate me Gollevainen. I wanna know what your talking about. The only use that I can think of for guns is either shore bombardment like recently in Israel or in close quarters littoral combat, like for example if you were fighting around Singapore, areas like that where there are lots of islands and such making it difficult to use ASMs and the enemy is probably quite close. Your use of faces and ...s has confused me.

I had Jane's Fleet Command (a very accurate naval command sim game. It's old but I reccommend it.) for years and I only used guns a few times. That's about as close as I have come to commanding a ship, I know it's lame, but I never had a whole lot of use for them.

Well a gun (and this has nothing to do with my love affair with artillery ) is still the most cost-effective naval weapon after mines.

Against threads which are with in the range of the ships main gun there is no other means to attack. In such close range -30 km there is no usability to missiles and frankly using expensive SSMs against targets that can be sinked/destroyed with artillery is just blain silly. You encounter enemy transportships, small, fast patrolcrafts, fixed instalations or spy-ships, what do you do?

In peacetime naval patrols in the ECC zone you might encounter foreing vessels exploiting your natural recourses...what do you do? Did the russian patrol boats fire a missiles against the japanese trawlers in the latest skirmish between those two countries?

No offence but computergames are computer games...no matter how respectfull publisher is behind them...To learn more about naval warfare I suggest everyone to READ something from the same publisher...

Thanks for hooking me up with the sweet info Gollevainen. Obviously, guns are still useful in many less intense situations. But as I said, they are still useful for littoral combat and in areas like the Persian Gulf, entrance to the Baltic, Straits of Mallacca, etc. where engagements are at a range too close for ASMs or if there are islands or civillian ships making things difficult for ASMs.

Lastly, having that gun on the bow makes sure everyone knows that your ship is a warship.