Before any such work as is mentioned in § 56-17 is commenced, the president or general managing officer of the company which proposes to cross the works of another company shall submit plans, specifications and descriptions of the proposed crossing and of the proposed appliances and methods of operation thereof to the president or other general officer of the latter company; and if the plans, specifications and descriptions are accepted or if no notice of suspension of the work on such crossing by the Commission pursuant to § 56-19 is received by the first named company within thirty days after such plans, specifications and descriptions have been delivered to the president, or any general officer of the company whose works are to be crossed, the first named company may proceed with the construction and operation of the crossing, under the plans, specifications and descriptions, and with the appliances and methods, so submitted.