BLOCK SIGNAL RULES D-251. On portions of the railroad, and on designated tracks as specified by the Time Table or by General Order, trains will be governed by block signals, whose indications will supersede the superiority of trains for movements in the same direction, with the current of traffic. 253. The Train Dispatcher must be advised in advance of any known condition that will delay the train or prevent it from making usual speed. 254. Except as affected by Rule D-251, all Operating, Signal and Interlocking Rules remain in effect. BLOCK SIGNAL AND TRAFFIC CONTROL SYSTEM RULES 261. On portions of the railroad, and on designated tracks as specified in the Time Table or by General Order, trains will be governed by block signals, whose indications will supersede the superiority of trains for both opposing and fo[lowing movements on the same track. 261(a). When interlocking signals display stop, trains and engines, after complying with Rules 663 or 671, must not move beyond interlocking limits until authorized by train order, Form R. 261(b). When controlled home signals display stop, trains and engines must not pass home signal at Controlled Point until authorized by train order, Form R. 262. A train for which the direction of traffic has been established must not move in the opposite direction without proper interlocking or controlled home signal indication or train order. effect. 263. The Train Dispatcher must be advised in advance of any known condition that will delay the train or prevent it from making usual speed. 264. Except as affected by Rules 261 and 262, all Operating, SignaJ and Interlocking Rules remain in effect.