Note: In the later years of the interplanetary rocket era of space travel, it would have been very rare for any ship to be ‘faster’ than any other for the simple fact that, for human comfort, ships would typically simply accelerate at one gravity for the first half of a trip, then decelerate at one gravity for the second half, so no matter the size or power of a ship, they would all take the same amount of time for the same journey, and very few ships would have been designed for any acceleration or deceleration faster than one gravity. So, as counter-intuitive as it seems, the Harrison would have to have a more powerful ship in order to reduce deceleration time for a bit after the turning point.