The train service in Japan looses rapidity, comfort and robustness against delays in morning peak hours especially, and it has been a serious social problem. On the other hand, the cost to purchase land for a new track is very high. An efficient train operation is proposed in this paper. The proposed train operation has substantially high rapidity and train density identical to a quadruple-track line, with a novel train scheduling based on full usage of a triple-track line. The significance of the proposed train operation on a triple-track line has been verified based on the calculations of waiting time and boarding time of passengers. Consequently train operators can keep the rapidity, moreover, raise track capacity by operating express and local trains like knitting on triple-track lines.