Complex sentence: The US claimed in 1963 that it could produce a 35 megaton fusion bomb, and put it on a Titan II (3700 kg payload), almost doubling the yield-to-weight ratio of the B-41.
Split into simpler sentences: The US claimed in 1963 that it could produce a 35 megaton fusion bomb, and put it on a Titan II (3700 kg payload). Almost doubling the yield-to-weight ratio of the B-41.