Comments by "Steve Valley" (@stevevalley7835) on "The Drydock - Episode 117" video.

  1. wrt the question on relining guns, I happened to read a US Naval Academy gunnery textbook from 1915 last week that describes the process in detail. At the turn of the century, a lot of guns were initially built without liners, and had to be bored out to make room for the liner when the gun was refurbished. The feed rate for the boring operation was about 6"/hour, so boring a 12-14" gun would take 4-5 days, running continuously, per pass, and it would take several passes to bore the gun sufficiently to allow insertion of a liner. Initially, the liners were of uniform diameter, which simplified the boring operation. The liners were inserted and removed by placing the gun in an oven and heating it, to cause the metal of the gun to expand, so the unheated liner could be inserted. Removing an existing liner amounted to heating the outside of the gun, while running cold water through the bore to keep the liner cool so it would not expand with the heated gun. Then pressing out the old liner with a press. Sometimes, the uniform diameter liners did not want to come out, and had to be bored out, consuming a great deal of time and expense. So the shift was made to boring the gun and turning the OD of the liner with a slight taper, so they would separate more readily.
    4
  2. wrt to the question about a fleet of Vanguards. in the Q&A section on Queen Mary post a few days ago, my reply to a question of what if the RN had completed all four Admirals followed the repercussions on the fleet due to treaty tonnage limits, resulting in the R-class ships going to the breakers for the fleet draw down called for by the First London Treaty in the early 30s. That opens up the possibility of the Admiralty having a very large number of dual 15" turrets on hand when the battleship construction moratorium ended at the end of 36. Using four turrets per ship, as Vanguard, requires a long hull, which would exceed the treaty 35,000 ton limit. The thought crosses my mind that, a KGV using 3 twin 15" turrets, instead of the 14" layout historically received, would result in lower displacement due to the smaller turrets and, because fewer guns, less ammunition carried, which might result in more speed. Additionally, the cost savings of using existing guns and turrets may make it possible to build more than the five KGV class ships that were built. But, would the RN really be comfortable building a battleship that would assuredly be outgunned by any other individual battleship, because such a KGV would only have 6 guns vs potential adversaries having 8 or 9. Or, would they take a compromise route and remount the used 15" guns in new triple turrets?
    2
  3.  @hughfisher9820  Yes indeed. When the Italians were working on the Caracciolo class battleships, the 15" guns were made in Italy, but were foreign designs, by Vickers, Armstrong and Schneider. When the USN started using nitrocellulose propellant around 1900, they didn't fully understand the dynamics of the powder and started blowing the muzzles off their guns. The entire production run of 12"/40 guns had to be brought back to the gun factory for new liners and to be hooped to the muzzle to make them safe to use. The Brits had a learning curve too. The early 12"/35s were taken off of the obsolete Majestic class battleships and mounted on the Lord Clive class monitors to provide fire support to ground troops. Copper choke was becoming an understood issue: where copper from the driving bands forms deposits in the bore which impede the shell's travel through the gun. The old 12"/35s had an extra trick "steel choke", where a ridge would form in the liner. The ridge would grow to the point where the shell would hit it with enough of a jolt to trip the fuse and detonate the shell. In one case, a monitor fired, a shell detonated at the muzzle and a nearby French destroyer was showed with shell fragments.
    2