"Turret Arrangement and Philosophy" Topic

I've been musing lately about why Japanese and German destroyers put two turrets on the rear of the ship and only one in the front. It seems like putting the heavy weight of your weapons on the stern indicates a less aggressive tactical doctrine?

I have no idea, however, that will not stop me from expressing an opinion. Placement may have a lot to do with stability of the vessel, aft turrets may offset the weight of the forward superstructure. As far as the Germans went, the surface fleet was intended, in part, for commerce raiding, so they may have anticipated being involved in more chases, where they were the ship being chased? Between the two, I would think stability. It is really easy to break a ship's back if the forward and aft weight load was off.

Using destroyer against anything bigger and it was most likely a night or action in smoke or fog and the torpedo would have been the primary attacking weapon. Guns to cover a retreat from a torpedo run makes sense.

Against anything equal there are a couple of ponts. Very few actions are straight on head to head coming at each other from opposites of 180 degrees. the ability to traverse the guns turrets or shields is more important than their placement. Arcs are parapmunt over whee they are put.

Another perspective is the idea that in an action against other like destroyers, what the expectation of the odds would always be against them. For the Germans, it was the fact of facing not only the RN but also the French that could be deployed in the Atlantic too.

For the Japanese it was also the threat of not just faing the USN, but the RN, the Dutch, the RAAN, the RNZN, and even the odd French too. So maybe guns in the back was not such a bad idea.

Not necessarily that the doctrine was less aggressive, far from it, but that they expected to be taking on either larger ships or larger numbers.

They were both quite aggressive. The Germans had torpedo boats taking on what everyone else had destroyers doing. They also tried to use guns normally found on a light cruiser on destroyers. Likeise the IJN shocked the world when their Specials came out. Even later the late war IJN the four twin 3.9" turrets on the 'Akisukis' (?) might have seemed a drop n caliber but the range and the rate of fire was incredible. No slouch compared to their previous 5 inch guns.

I think it had more to do with logic like this:

• We need to stuff as many main guns as possible on this little tin can.
  
• The front of the ship is wet in high seas and/or high speeds, so we have to raise it an extra deck (and often: add a clipper bow).
  
• Now that the bow is so high, we can't put a superimposed turret in front without hurting the ship's stability (esp. in hard maneuvers, part of a DD's job duties).
  
• Add more torpedo tubes! We need more than the other guys! There goes the deck space in the middle of the ship…
  
• The stern is the only place left for an extra turret.

As gamers we make a big deal about end-on fire, but the truth is that guns were expected to fire on the broadside most of the time. Shots fired off the bow or stern are generally only snap fire or potshots, e.g. during stern chases or sudden brief opportunities during fleet maneuvers. Ships with all the guns at one end (Nelson class, Richeleiu class, Dunkurque class) or deck-level turrets behind the superimposed forward turret (IJN cruisers and seaplane carriers) look weird to us, but make perfect sense to add power to the broadside while minimizing the weight of armor to protect the magazines and hoists.

- Ix

My first thought was to keep the superstructure and command above the smoke after firing.

The German destroyers didn't use twin turrets. They were built with single mounts like most pre WWII destroyers.

German light cruisers built in the 30s and Japanese destroyers did make use of 3 turrets, sited 1 forward and 2 aft. There were a number of reasons for this.

The primary reason was design stability. There is a balance between buoyancy and the metacentric height of the hull. Metacentric height is analogous to center of gravity. The more weight you add to the ship above the center of gravity, the more it will roll and the harder it becomes to keep the ship from capsizing in the event of flooding.

The German cruisers struggled to find a way to pack in all the features they wanted while still trying to cope with treaty displacement limits. Their cruisers were so excruciatingly overthought the 2 aft turrets were set slightly off the centerline, one to port, the other to stbd.

Additionally, knowing full well their likely opponents, the UK and France would have MANY more ships, putting the weight of their battery to stern to engage pursuers was a likely innovation.

The Japanese struggled to get the absolute most out of every ton of steel they planned to put in the water. The result was to press the math on seaworthiness to the edge of operational safety. Having 2 turrets aft lowered their destroyer's topweight, reducing the metacentric height. Even so, their efforts came back to haunt them. During a fleet exercise in 1934 the torpedo boat Tomozuru capsized in a storm. This forced a wholesale reappraisal of stability throughout the fleet, and extensive modifications to dozens of warships, including a carrier, at sea and under construction.

The Japanese naval doctrine deemed the destroyers to be primarily a torpedo delivery system. Their guns were not a primary consideration.

Stability ended up being a major gremlin plaguing navies going into WWII. Topweight restrictions inhibited the addition of light and medium AA weapons. Mid 30s US destroyers were so restricted that they were withdrawn to ASW escorts late in the war. Many ships in various navies wound up losing a gun turret or mount to make room and swap the topweight to allow for significant additional AA weapons.

Some later German destroyers (1936a Mob) carried a trim 5.9" turret forward. It was too heavy and led to poor stability and seakeeping

Ships would always try to use their broadside so all turrets could fire. So most of the time whether the turrets are on the front or the back doesn't matter, especially for destroyers whose main weapon was torpedoes.

A destroyer's primary offensive weapons were its torpedoes, which could most effectively be fired on a bow angle (port or starboard), steaming in the general direction of an enemy force. Guns were meant as a defensive weapon, in which role they would typically be fired on the broadside approaching enemy torpedo craft. This second mission applied to both self-defense and escort duties against surface attack; for those, the bow one of the least important arcs for the guns to cover.