This year has been really busy with most of my spare time sent making parts for the battleship's six 5" deck guns and a few other items. Originally in 1914 the ship had 19 5" guns but as aircraft became a threat, 13 of them were removed and replaced with antiaircraft systems.
One seemingly simple task was making replacement adjustment screws for part of the sighting system. We'll understand the function better once the barrels are set into the mounts and all of the gear boxes are connected. In all of the archives for the New York class nobody has found information on this particular part. We don't even know what it's called but they obviously needed to be repaired. The screws are just over 18" long, 1-1/8" diameter and 7 TPI LH threads. The employee that usually locates and purchases parts found some 1-1/8-7 LH x 36" all thread for the staggering sum of $198.00 each. We needed 3 to make 6 screws. We immediately agreed that I could cheat dimensions and "almost 18 inches" was going to have to do. All that had to be done on one end was to machine it down to fit into a bronze bushing. The other end was a little more complex, with three different diameters, a pilot hole for a taper pin and a larger diameter piece that had to be shrink fitted to the shaft.
This is the finished screw installed in its casting and attached to the slide of the gun. The slide is what the barrel moves backward in during recoil. The slide weighs about 3,500 pounds and has a bronze liner surrounding the barrel.
Even after cleaning and paint to corrosion damage over 112 years is easy to see. The replacement screw is installed as is the universal coupler on the right end. I made three of those. Some of the original screws were in very rough condition. Surprisingly, once the ends that were in bushings were freed, all six screws were unscrewed from the trapezoidal piece that they went through.
The biggest problem with this job was the size of my lathe. The spindle bore is just large enough to take 1" stock so the 1-1/8" stock had to be supported in a sleeve and steady rest. The sleeve was a close "tap on" fit. After every feature was machined I had to reposition the steady rest. That proved very time consuming since concentricity had to be maintained. The final feature on the 3 feature end was a journal over which a larger piece was joined by heat shrinking. It was very satisfying to hear each hot piece drop home, knowing that it was there for the long term.
Test fit in my shop. The trapezoid was backwards but it fit and worked.
Earlier I mentioned that the reproduction screws were going to be a little short of the original length. This is where most of the difference was absorbed. The end cap was solid bronze. The designers were very generous in their use of bronze when the ship and guns were designed in 1910-1912.
All six screws finished along with a couple of the originals. The originals were made from a solid piece of stock with the larger boss being integral to the entire piece. My little lathe was not capable of making a 7 TPI LH thread so we did what we could.
One seemingly simple task was making replacement adjustment screws for part of the sighting system. We'll understand the function better once the barrels are set into the mounts and all of the gear boxes are connected. In all of the archives for the New York class nobody has found information on this particular part. We don't even know what it's called but they obviously needed to be repaired. The screws are just over 18" long, 1-1/8" diameter and 7 TPI LH threads. The employee that usually locates and purchases parts found some 1-1/8-7 LH x 36" all thread for the staggering sum of $198.00 each. We needed 3 to make 6 screws. We immediately agreed that I could cheat dimensions and "almost 18 inches" was going to have to do. All that had to be done on one end was to machine it down to fit into a bronze bushing. The other end was a little more complex, with three different diameters, a pilot hole for a taper pin and a larger diameter piece that had to be shrink fitted to the shaft.
This is the finished screw installed in its casting and attached to the slide of the gun. The slide is what the barrel moves backward in during recoil. The slide weighs about 3,500 pounds and has a bronze liner surrounding the barrel.
Even after cleaning and paint to corrosion damage over 112 years is easy to see. The replacement screw is installed as is the universal coupler on the right end. I made three of those. Some of the original screws were in very rough condition. Surprisingly, once the ends that were in bushings were freed, all six screws were unscrewed from the trapezoidal piece that they went through.
The biggest problem with this job was the size of my lathe. The spindle bore is just large enough to take 1" stock so the 1-1/8" stock had to be supported in a sleeve and steady rest. The sleeve was a close "tap on" fit. After every feature was machined I had to reposition the steady rest. That proved very time consuming since concentricity had to be maintained. The final feature on the 3 feature end was a journal over which a larger piece was joined by heat shrinking. It was very satisfying to hear each hot piece drop home, knowing that it was there for the long term.
Test fit in my shop. The trapezoid was backwards but it fit and worked.
Earlier I mentioned that the reproduction screws were going to be a little short of the original length. This is where most of the difference was absorbed. The end cap was solid bronze. The designers were very generous in their use of bronze when the ship and guns were designed in 1910-1912.
All six screws finished along with a couple of the originals. The originals were made from a solid piece of stock with the larger boss being integral to the entire piece. My little lathe was not capable of making a 7 TPI LH thread so we did what we could.
