With the success of the Iowa 16" turret project now on display in the ward room of the Battleship New Jersey Museum and Memorial, I offered and it was accepted to build another of its characteristic weaponry, the 5" multi-purpose turrets. Orginally, the Iowas had ten of these (5 on a side), but during the 1980s refits, 4 were removed to make room for the missile launchers.
With the response I had posting all the gory details about that build on this forum, I’ve decided to do it again with this one.
Unlike the last project, this will be entirely scratch-built, again relying heavily on resin 3D printing. With the lessons learned on the last project, I am looking forward to this project being a little less stressful. I was originally intending to build it in 1/35 scale with the Takom model of the gun house (like the Missouri turret) to streamline the build somewhat. That plan changed when my hobby shop sold their last one and none were available from any of their sources. I had already offered the model to the ship and it was accepted, so I bit the bullet and proceded with a full scratch-build. Since I was no longer married to the Takom model, I changed scale to 1/48.
1/48 is O’scale and there are aftermarket parts that I may be able to use. It’s also 30% smaller and fits my printer much better. It’s still much bigger than the 1/72 of the previous model and more details will be able to be rendered. And as before, all of the design will be done on SketchUp Pro 2023.
The 5" turret system, while not a slam dunk, is much simpler than the big gun’s. For starters it occupies only three decks instead of six. It has two guns instead of three. It doesn’t have that massive range finder that was a drawing and building challenge. I also found very good reference material with more dimensions so my sizing will be less anxiety producing. There are still some abiguous areas which may require me to make another 3D scanning field trip to the ship later in the month.
This turret is a marvel of mechanical engineering. It was first fielded in the mid-1930s and was used on ships almost unchaged until the 1990s. It is considered a semi-automatic weapon. Like the 16" guns, the projectiles and powder are separate, but unlike the big gun, the powder is contained in a metal cartridge that is stored and loaded separately from the projectiles. The projectiles weigh around 55 pounds, and the cartridge with powder about 22 pounds.
From the point the projectile and powder are dropped into the loading tray, the gun is automatic. The breach opens, the projectile and powder cartridge are rammed into the chamber, the gun fires, the breach opens and ejects the spent cartridge out a chute and out of the gun house onto the deck. Because of this automation the gun is capable of firing a round every 3 to 4 seconds. But, getting those projectiles and cartridges from the magazines into the loading tray is all manual and requires a lot of lifting, moving and loading operations with a lot of men. It’s hard work and normal rate of fire with a trained crew is 15 rounds a minute, but the gun is capable of 22, and with lots of practice, a crew could reach that speed in bursts. It explains why battleships had load training machines on their upper decks so the crews could regularly drill to get up to speed. In the 80s refit, the loading trainers were removed and training took place in the gun turrets themselves.
There were many variations of this versitile weapon and they were found on almost every kind of ship in the fleet. They were found in single and double open mounts. In the open mounts, the fuzes were set right on the gun platform. The 5" guns could fire many different kinds of ammunition. For anti-aircraft the first fueses were time variable. Depending on the altitude of the target, the time of flight was calculated and the fuse set to detonate after that many seconds elapsed. Later in WW2, the proximity fuze was invented. It contained a miniature, battery-operated, radio ranging system that would detonate when the reflected signal was received from the aircraft target. The Japanese didn’t know about this advance (it was as secret as the Norden Bombsight) and thought we had the most accurate gunners in the world.
On the enclosed turrets, the fuze settings was an ingeiouse device that adjusted the fuze while it was on the elevator from the projectile handling room (below the turret one deck) to the gun house. When it arrived at the gun house, all the loader had to do was lift it out of the hoist and place it into the loading tray.
And another big difference (for me) is the only rotating structures are the gun house itself and the projectile and powder hoists that move munitions from the gun handling room to the gun house. That’s a far cry from the five rotating decks on the massive Iowa Turret. It also means I don’t have to construct that cylindrical barbette that surrounds the big turret that I had to open like a clamshell to show the insides. Therefore; this will be a much more conventional and sedate build.
Even within the enclosed twin guns there were differences. The Takom model was a Mark 38 turret. This was found on destroyers and smaller vessels. It was much lighter and less armored. It also had some external differences such as exposed bolts, the training buffer (device to keep turret from rotating where it would hit part of the ship) and the reach hatch arrangement were different. The Fast Battleships’ turret was much heaver with 2.5" armor plating. It would stop a 16" shell, which BTW, the big turrets could, but it would stop aircraft machine gun fire and probably rockets. These differences meant I would have needed to modify the Takom kit. As it stands now, I’ll just build it right the first time.
I’ve made a good start.