Thanks for the movies, Soot. Most of them are in some form of fast motion, but actually the complete cycle time for one of the 10 or 12 inch disappearing rifles only took on average 3 minutes and it included firing, recoil to loading position, calculating the ship's next position, plotting shell impact zone, sponging, shell ramming, powder loading, closing breech block and setting primer, return to battery, traversing carriage, elevating or depressing the tube, aim checking and firing again.
Gulfcoast, you are right, the lower part goes into a big hole and almost all of the tube goes down into this hole as well for the re-loading cycle, completely protected from the enemy warship's direct fire. It's good to remember that the technology which made these guns and emplacements obsolete was the airplane, Not fancy rangefinder or more accurate fuses. Tube artillery did not have nearly the accuracy, especially when it comes to range to give these installations any kind of realistic challenge, especially from a ship's rolling and pitching platform. We are NOT thinking of one of these as a project for the future, No.
Josco, thanks for that excellent online book! Lots of good stuff there!! BIG download, but I crammed it into the old laptop without any curls of smoke from under the keyboard.
We tried to think of another Endicott Period artillery piece which could have been a significant deterrent to enemy warships attacking American ports during the Spanish-American war. We came up with the one which probably caused more fear in the hearts of enemy Admirals and ordinary seamen alike, The 12" Seacoast Mortar, Model 1890 M1 on the Seacoast Traversing and Elevating Carriage Model 1896 M1. We think photos and engineering drawings of these 136,000 pound mortars are really interesting. What do you think?
Tracy and Mike
P.S. Unless otherwise noted all of the diagrams and images presented here are photographer unknown and draftsman unknown, but coming from the Rican Havock website.
Note the traversing crank and the elevating hand wheel and the azimuth scale and azimuth pointer on the base plate periphery.
I really love this feature-labeled photo. It shows the recoil control system clearly. The narrow, rear, cylinder going down and back from the right trunnion is the hydraulic shock absorber with it's oil reservoir to the rear. The recuperator spring set, forward, with 10, large dia. coil springs is what brings the tube up, out of the pit after recoil, refilling the hydraulic cylinders with oil from the reservoir as the tube rises.
One of the old-style 12" mortar pits with very little room for actual serving of the mortars. By 1905 most of these had one mortar removed, so the crews had some chance of moving about the guns without colliding. Fort Desoto, Florida. The only 1890 12" Seacoast Mortars in the United States today are located at Fort Desoto near Tampa, Florida.
Even with one Mortar removed, the crowding during operation of these guns is evident. 3 of the 800 or 824 Lb. armor piercing or deck piercing shells are visible. 16 foot rammers were close behind. With 65 Lbs. of nitrocellulose powder, the shell could go almost 7 miles and penetrate 6" of deck armor at that range and the recoil of the tube was 23". In a typical early battery, with all sixteen Mortars ranged in, a rectangle 150 yards long and 100 yards wide typically held all the shell splashes. No wonder enemy navies were concerned!!
The powerful Recuperator springs, elevating rack and elevating wheel shaft and bracket on the left of a present day Mortar at Fort Desoto.
2 gears of a 3 gear set are shown here. The elevating hand wheel is off the photo to the right and the pinion gear is hidden under the massive cast iron frame on the same shaft that the partially hidden gear, engaged with the hand wheel shaft gear is on.
Some interesting markings. These were all made near Troy, New York at the Waterveliet Arsenal. The 1896 carriages were made by 4 or 5 different foundries. Are those some azimuth graduations on the traverse circle edge?
The large pedestal in front of the carriage is the Traversing crank gearbox which transfers two-man power on the cranks though bevel, spur and pinion gears and shafts to the huge circular rack which surrounds the gun and turns the entire Mortar tube and carriage due to changes in azimuth. You get an idea of the size of these seacoast mortars when an adult stands to the rear of the gun in this view and can look down the center of the 12" bore along it's axis.
