Tiny Tim (rocket)

The Tiny Tim was an American air-to-ground rocket used near the end of the Second World War.

History


The Tiny Tim was built in response to a United States Navy requirement for an anti-ship rocket capable of hitting ships from outside of their anti-aircraft range, with a payload capable of sinking heavy shipping. The Tiny Tim was manufactured using 11.75-inch (298 mm) pipe, which was chosen because it was already being manufactured for oil well casings. This also allowed using four modified Holy Moses propellant charges, and payload adapted from 12-inch naval gun shells.

According to the China Lake Weapons Digest, the Tiny Tim was "... designed by the Caltech-China Lake team as a bunker-buster, Tim was the first large aircraft rocket, and, although it saw only limited service in WWII, it helped form the foundations of many postwar developments in rocketry."

The "Tiny Tim" name came from the fact that the drawings of the rocket, which were made without official approval, were presented to the supervisor of the design team in late December.

The Tiny Tim's diameter of 11.75 in (29.8 cm) was the first Allied aerial rocket to have a larger calibre than the Luftwaffe-deployed bomber destroyer aerial rocket ordnance, the Nebelwerfer-based BR 21 of 21 cm (8-1/4 in) calibre. The Tiny Tim's large diameter allowed a sizable 148.5 lb (67.4 kg) semi-armor-piercing high-explosive warhead, some 60 lbs (27 kg) heavier than the BR 21's 40.8 kg (90 lb) warhead. The Tiny Tim had a maximum range of 1,500 meters (1,640 yards), some 200 meters greater than the BR 21's time-fuze limited 1.2 km detonation range from launch.

They were used by the United States Navy and United States Marine Corps near the end of the war during the Battle of Okinawa, and during the Korean War. A problem with the sheer power of the rocket motor causing damage to the firing aircraft was resolved by having the Tiny Tim drop like a bomb, and a lanyard attached to the rocket would snap, causing the rocket to ignite. Common targets included coastal defense guns, bridges, pillboxes, tanks, and shipping. An ambitious operation to use the Tiny Tim against German V-1 sites as part of Operation Crossbow, code-named Project Danny, was planned but cancelled before the squadrons assigned could be deployed to Europe.

Common Tiny Tim delivery aircraft during World War II included the PBJ-1 Mitchell, F4U Corsair, F6F Hellcat, TBM Avenger, and the SB2C Helldiver.

After World War II, the United States Navy's rocket laboratory at Inyokern, California developed an even larger version of the Tiny Tim, called "Richard", which was 14 inches in diameter and one of the largest air-to-surface unguided rocket ever developed for the US military. While tested, it was never placed in production. The United States Navy also experimented with a version of the Tiny Tim which was a two-stage rocket, with another Tiny Tim rocket motor mounted behind a complete Tiny Tim. Like the Richard, it never moved beyond the research and development stage.

During the second half of the 1940s Tiny Tim also had a short civilian life, when it was modified to be used as a booster for the first U.S. sounding rocket WAC Corporal.