The term carrier includes any express company, sleeping car company, carrier by railroad, subject to the Interstate Commerce Act (24 Stat. 379, as amended; 49 U.S.C. 1 et seq.), and any company which is directly or indirectly owned or controlled by or under common control with any carrier by railroad and which operates any equipment or facilities or performs any service (other than trucking service) in connection with the transportation, receipt, delivery, elevation, transfer in transit, refrigeration or icing, storage, and handling of property transported by railroad, and any receiver, trustee, or other individual or body, judicial or otherwise, when in the possession of the business of any such “carrier.”

(a) The term “carrier” shall not include any street, interurban, or suburban electric railway, unless such railway is operating as a part of a general steam-railroad system of transportation, but shall not exclude any part of the general steam-railroad system of transportation now or hereafter operated by any other motive power.

(b) The term “carrier” shall not include any company by reason of its being engaged in the mining of coal, the supplying of coal to carrier where delivery is not beyond the tipple, and the operation of equipment or facilities therefor or any of such activities.

The Interstate Commerce Commission is hereby authorized and directed upon request of the Mediation Board or upon complaint of any part interested to determine after hearing whether any line operated by electric power falls within the terms of this part.

The term employee as used in this part includes every person in the service of a carrier (subject to its continuing authority to supervise and direct the manner of rendition of his service) who performs any work defined as that of an employee or subordinate official in the orders of the Interstate Commerce Commission now in effect, and as the same may be amended or interpreted by orders hereafter entered by the Commission pursuant to the authority which is hereby conferred upon it to enter orders amending or interpreting such existing orders: Provided, however, That no occupational classification made by order of the Interstate Commerce Commission shall be construed to define the crafts according to which railway employees may be organized by their voluntary action, nor shall the jurisdiction or powers of such employee organizations be regarded as in any way limited or defined by the provisions of this Act or by the orders of the Commission.

The term “employee” shall not include any individual while such individual is engaged in the physical operations consisting of the mining of coal, the preparation of coal, the handling (other than movement by rail with standard locomotives) of coal not beyond the mine tipple, or the loading of coal at the tipple.

The term representative means any person or persons, labor union, organization, or corporation designated either by a carrier or group of carriers or by its or their employees, to act for it or them.