Before revision: This was an important consideration for the Advanced Passenger Train in the United Kingdom, where the lengths of block sections limited speeds and demanded a new braking system be developed.Leonard Hugh Williams, "Advanced Passenger Train: A Promise Unfulfilled", Ian Allan, 1985, The length of block sections have to be balanced on a case-by-case basis .
After revision: This was an important consideration for the Advanced Passenger Train in the United Kingdom, where the lengths of block sections limited speeds and demanded a new braking system be developed.Leonard Hugh Williams, "Advanced Passenger Train: A Promise Unfulfilled", Ian Allan, 1985, There is no perfect block section size for the block-control approach .