ie: 300 feet - New electromagnetic aircraft launch system: Newport News Shipbuilding division conducts "dead-load" testing on carrier USS John F. Kennedy's electromagnetic aircraft launch system. This phase, the shipbuilder said, involves launching "large, wheeled, car-like structures of graduated weights up to 80,000 pounds to simulate the weight of actual aircraft" off the topside of the Kennedy and into the water below. The vehicles travel more than 300 feet down the track at more than 150 miles per hour, simulating an aircraft's launch. But unlike a plane, they hit the water, sometimes with a skip like a smooth stone on a river.
They use actual aircraft wheel and tire assemblies as it is required for the weight (and stress) as well as friction coefficient. Them sneakers ain't cheep.
In case you don't know - the old catapults used steam to drive the piston down the deck. They were a pain to set up and needed constant maintenance. In keeping with the Navy's move to all electric ships, they developed this electromagnetic launch system - over the last 30+ years!!! The first ship to use it was the first in this class. That ship delivered 2 years late due to issues with this system. If you watch old movies of carriers you will see the steam follow the jet down the deck.
My first ship was an Aircraft Carrier, the USS Essex CVS-9. This was the newest & biggest carrier in WW2. Commissioned in 1943. I loved to see the aircraft launched by the steam catapult. The airmen got hazardous duty pay and one day I found out why. A aircraft landed and the cable arresting cable snapped in half. When that happens, the cable ends wiped at lighting speed and cut two guys in half like a razor blade. Not a job I wanted to do. Also, I believe there is a YouTube video that shows an airman getting sucked into a jet engine and flames shooting out of the rear of the engine. That engine sucked that guy in as quick as it does a bird. Vet
Since the catapult attaches to the nosewheel, I can only imagine the engineering that goes into carrier aircraft nosegear.