Various patterns of the 5-inch Whitworth shell, case shot and bolt are interesting projectiles.
Four Whitworth 5-inch muzzle loading rifles were indeed captured in the blockade runner Princess Royal on 29 January 1863. One is currently at the Washington Naval Yard and the Navy Historical Center states “… two similar Whitworths captured in the blockage runner were used by the Federals against Charleston, but were deemed highly unsatisfactory. Shells exploded prematurely and tended to jam in the bore during loading and accuracy was poor. When the inner tube of one gun slipped, both pieces were taken out of service; the disabled gun is now at West Point.” Reference: John C. Reilly, Jr., The Iron Guns of Willard Park, Naval Historical Center, 1991, page 84.
Olmstead, Stark and Tucker, The Big Guns, state “After 111 rounds, one 5-inch Whitworth was disabled by the breech starting back inside the reinforcing sleeve far enough to close its vent.” “While striving to ram one of them [a round] home, four men were killed by a premature explosion of its charge.” (Page 141)
Jack Bell also notes “…that four men on the crew were killed trying to ram one home” and that documents in the Washington Navy Yard acknowledge it was the ammunition (Bell-445).
The gun did not blow-up and was on display at West Point’s Trophy Point when I last visited the West Point Museum to measure their collection.
Mr. Whitworth designed some 5-inch Whitworth rifle projectiles specifically to penetrate armor plate. To accomplish this, his armor penetrating shells and shot were made of steel. Holly states Mr. Whitworth used Bessemer steel (page 199) which was some of the finest of its day. Armor penetrating shells had a flat nose and the impact of the shell with the plate caused immense heat that detonated the bursting charge. To “…regulate the time of ignition, the bursting charge was surrounded with a proper thickness of flannel, or other material which is a non-conductor of heat.” Holly, pages 493 and 494. I have not been able to document whether this shell was fired at Charleston, but a specimen is on hand at the West Point Museum.
The British specification for the 5-inch Whitworth projectile was 4.965-inches across the flats and 5.465-inches across the angles.
I inspected the 5-inch shell (old inventory #3226), 5-inch case shot (old inventory #3225) and bolt (old inventory #9512) that are on hand at the museum. I don't recall if the inventory cards revealed if the shell or bolt had been produced at the Washington Naval Yard or whether they came off the blockade runner, but I will check my notes.
The shell casing weighed 65.0 pounds without its fuse and bursting charge. Computer modeling the shell revealed a complete specimen would weigh at least 70.0 lbs, depending upon the size of the bursting charge that was used. This is a very long shell (21.5-inches) and has a large bursting charge chamber. The case shot casing weighed about 50.0 pounds (the casing was missing its payload, bursting charge and fuse). A complete round would also likely weigh at least 70.0 pounds. The case shot and bolt were the same specimens listed by Jack Bell on pages 450 and 447.
There were several lengths and weights of shells and bolts made for 5-inch Whitworth rifles. Some weigh 81 pounds; hence this rifle at times is referred to as the 80-pounder, but Whitworth designated it the 70-pounder. The ammunition used at Charleston was of the 70-pound classification.
The heaver ammunition may have been limited to tests conducted in England or on export rifles. As a matter of interest, Holly lists his 5-inch-inch blind shell as 19-inches in length, 81 pounds including a bursting charge of 3.75 pounds. As a point of reference, that is approximately the same size bursting charge that was used in the 80-pounder Parrott.
Respectfully, John B
