(dissenting).
With respect, I am unable to agree with the Court that the subject matter of Act No. 431 has not been preempted by the federal Railway Labor Act.2 In my opinion, the federal government has occupied the field covered by the Pennsylvania statute, and the latter must, under the Supremacy Clause,3 give way.
There is no disagreement as to the general principles involved. As Mr. Justice Roberts said in speaking for this Court in Bessemer & L. E. R. Co. v. Pennsylvania, Public Utility Commission, 430 Pa. 339, 243 A.2d 358 (1968) cert. denied, 393 U.S. 959, 89 S.Ct. 395, 21 L.Ed. 2d 373 (1968), reh. denied, 393 U.S. 1045, 89 S.Ct. 614, 21 L.Ed.2d 597 (1969):
“It is certainly too late in the development of constitutional law to say that Congress may not pre-empt an entire field by the passage of a broad based statute, even though the regulations passed pursuant to that statute do not in fact cover every possible situation. Moreover, once such a statute is passed, and the intention to pre-empt state law in the area becomes manifest, the various states may not pass legislation even supplemental to the federal rules, so long as the area affected by these supplemental acts coincides with the federal baliwick.” (Emphasis added.) 430 Pa. at 346, 243 A.2d at 361.
The Court spoke in similar vein through Mr. Justice Cohen in Mamula v. United Steelworkers, 409 Pa. 175, 185 A.2d 595 (1962):
“Where the Congress of the United States enacts a comprehensive statute which is intended to occupy the field, the Supremacy Clause of the United States *86Constitution requires that the state legislature and judiciary defer to the superior command of Congress. This doctrine is particularly applicable in the area of labor law which is covered in detail by numerous comprehensive federal statutes.” 409 Pa. at 178, 185 A.2d 595 at 597.
The problem, of course, is to determine whether a particular Congressional enactment has occupied a particular field so completely as to indicate a clear intention to preclude state regulation. See City of Chicago v. Atchison, Topeka and Santa Fe Railway Co., 357 U.S. 77, 78 S. Ct. 1063, 2 L.Ed.2d 1174 (1958). Recognizing the perplexities that inhere in making such a determination, I am nevertheless unable to subscribe to the Court’s holding that Congress has left the states free to legislate in the area of rates of pay, rules and working conditions of employees of railroads involved in interstate commerce. Under today’s decision, the legislature of any state could by statute or authorized regulation prescribe a work condition for railway labor, provided only that the subject matter of the condition was not already a matter of agreement between a railroad and its employees. This cannot have been the intent of the Congress.
Guides to Congressional intent to preempt an area previously occupied by the states include the pervasiveness of the scheme of federal regulation, the dominance of the federal interest in the field, and possible inconsistency of the state policy with the objective of the federal statute.4 *87All three criteria point to preemption in the present case.
The large field in which this case lies is that of interstate railroad transportation. The pervasiveness of the Congressional interest in and regulation of railroads need not be elaborated upon.5 “National rather than local control of interstate railroad transportation has long been the policy of Congress.” Chicago v. Atchison, Topeka & Santa Fe Railway Co., 357 U.S. 77, 87, 78 S.Ct. 1063, 1069, 2 L.Ed.2d 1174 (1958). Turning specifically to the labor aspect of interstate railroad transportation, the relevant federal law is, of course, the Railway Labor Act. Adopted in 1926, that Act is “essentially an instrument of industry-wide government. . . . Like the Safety Appliance Act, the Railway Labor Act is ‘all-embracing in scope and national in its purpose, which is as capable of being obstructed by state as by individual action.’ United States v. California, 297 U.S. 175, 186, 56 S.Ct. 421, 425, 80 L.Ed. 567 [573].” California v. Taylor, 353 U.S. 553, 565-566, 77 S.Ct. 1037, 1044, 1 L.Ed.2d 1034, 1042 (1957). Its purpose is “to encourage collective bargaining by railroads and their employees in order to prevent, if possible, wasteful strikes and interruptions of interstate commerce. . . .” Detroit & Toledo Shore Line Railroad Company v. United Transportation Union, 396 U.S. 142, 148, 90 S.Ct. 294, 298, 24 L.Ed.2d 325, 331 (1969). “To this end, the Act established rather elaborate machinery for negotiation, mediation, voluntary arbitration, and conciliation. ... It imposed upon the parties an obligation to make every reasonable effort to negotiate a settlement and to refrain from altering the status quo by resorting to self-help while the Act’s remedies were being exhausted. ... A final *88and crucial aspect of the Act was the power given to the parties and to representatives of the public to make the exhaustion of the Act’s remedies an almost interminable process. As we noted in Brotherhood of Railway & Steamship Clerks v. Florida E. C. R. Co., 384 U.S. 238, 246, 86 S.Ct. 1420, 1424, 16 L.Ed.2d 501, 507 (1966), ‘the procedures of the Act are purposely long drawn out, based on the hope that reason and practical considerations will provide in time an agreement that resolves the dispute.’ ” The Detroit & Toledo Shore Line Railroad Company v. United Transportation Union, supra, at 148-49, 90 S.Ct. at 298, 24 L.Ed.2d at 332. See also Railroad Trainmen v. Terminal Co., 394 U.S. 369, 377-380, 89 S.Ct. 1109, 22 L.Ed.2d 344, 354-55 (1969).6
Central to the process of dispute resolution created by the Railway Labor Act are collective bargaining relating to rates of pay, rules and working conditions, and maintenance of the status quo during negotiations and thereafter during the stages of mediation mandated by the Act.’7' Shore Line Railway Co. v. Transportation Union, *89supra, 396 U.S. at 150, 90 S.Ct. 294, 24 L.Ed.2d at 332. There can be no doubt that a state-imposed working condition removes that condition from the scope of collective bargaining, which, as above stated, is central to the federal scheme. The bargaining freedom of at least one of the parties is thereby necessarily restricted. Adoption by states of statutes imposing such conditions also inevitably change the status quo, which under the Act is to be maintained while bargaining, and the other steps in the federal machinery, is carried out.
In California v. Taylor, 353 U.S. 553, 77 S.Ct. 1037, 1 L.Ed.2d 1034 (1957) the Supreme Court dealt with the applicability of the Railway Labor Act to a state-owned railroad, the Belt Railroad. Under California law the employees of the Belt Railroad, being state employees, had no right to bargain collectively with the state concerning those terms and conditions of employment which were fixed by the civil service laws of the state. The Supreme Court held that the Railway Labor Act applied to the Belt Railroad, and that the policy of the state must therefore give way. Crucial to the decision was the purpose and policy of the Railway Labor Act to protect and promote collective bargaining. “[T]he Act’s policy of protecting collective bargaining comes into conflict with the rule of California law that state employees have no right to bargain collectively with the State concerning terms and conditions of employment which are fixed by *90the State's civil service laws. This state civil service relationship is the antithesis of that established by collectively bargained contracts throughout the railroad industry.” 353 U.S. at 559, 560, 77 S.Ct. at 1041, 1 L.Ed.2d at 1039. Accord, International Longshoreman’s Association v. North Carolina State Ports Authority, 370 F.Supp. 33 (E.D.N.C.1974).
There is no question that the length of a pay period is a “working condition” and subject to the provision of Sec. 6 of the Railway Labor Act. Indeed, the record shows that pay periods have been so treated for many years by the parties to this dispute.8 That working condition — which the legislature of Pennsylvania has by Act No. 43 declared to be nonbargainable — stands in no different light than the working conditions which in California were fixed by that state’s civil service laws. The same reasons which impelled the Supreme Court to hold that since the federal Act applied to the Belt Railroad the policy of California must give way, dictate that the policy of Pennsylvania as stated in Act No. 43 must also give way.9
*91The Commonwealth Court, in my view, was entirely sound in its analysis of the issue here involved and in the conclusions it reached. I quote at length the following passage of Judge Rogers’ opinion:
“We have concluded that the Act of 1971, P.L. 221, is an attempt on the part of the state to regulate this working condition in the interest of employes; that it has the effect of changing working conditions without the notice and bargaining requirements of The Railway Labor Act; that it is an interference with and an intrusion upon Federal requirements; and that it offends the Supremacy and Commerce clauses hereinbefore cited. Although the Act of 1971 is expressly subject to the provisions of existing labor agreements, it can and in this case does change a customary working condition contrary to Section 6 of The Railway Labor Act as interpreted by Detroit & Toledo Shore Line Railway Company v. United Transportation Union, supra. It substitutes for customary conditions, until an agreement is reached, the heavy and immediate hand of state law for the collective bargaining process which Congress has declared to be the best and only means of changing such conditions. If we should hold that Pennsylvania may regulate customary pay periods without the agreement of the parties required by The Railway Labor Act, the state could similarly effect (and except for our supersedeas would have here effected) changes in existing practices so drastic as to render subsequent bargaining thereon pointless. Or, state regulations could be instituted during bargaining arbitration or mediation under The Federal Railway Act so favorable to one of the parties as to render it impossible realistically for the representatives of that party to relinquish the advantage so conferred at the *92bargaining table although the other party is prepared for a work stoppage unless a change is made.
“The Act of 1971, P.L. 221 is artful in its express subservience to hiring contracts and labor agreements and we would have more difficulty finding interference with Federal requirements had the Act expressly exempted customary practices or had the Secretary construed the Act as intending the exemption of customary practices. We do not quarrel with the Secretary’s construction, for if the Act is not intended to act on customary pay periods different from the weekly requirement it stipulates, there is nothing for it to act upon, unless there is somewhere in Pennsylvania a railroad enterprise with no labor agreement. The result is that the appellants have been ordered instantly to change a working condition other than by the procedures of The Railway Labor Act. This brings the case clearly within the rulings of California v. Taylor, 353 U.S. 553, 77 S.Ct. 1037, 1 L.Ed.2d 1034 (1957), holding that a state statute denying state employes collective bargaining rights was superseded as to employes of a state owned railroad by The Railway Labor Act, and Local 24, I. B. of T. v. Oliver, 358 U.S. 283, 79 S.Ct. 297, 3 L.Ed.2d 312 (1959), holding that a state antitrust law must give way to provisions of a labor agreement reached under the provisions of the National Labor Relations Act.”
Baltimore & Ohio R. R. v. Department of Labor & Industry, 12 Pa.Cmwlth. 292, at 298-300, 314 A.2d 862 at 865-66 (1974).
Because I find that the Act of 1971 is invalid under the preemption doctrine, I do not reach the questions of the constitutionality of the Act under the Equal Protection Clause of the Fourteenth Amendment to the Constitution of the United States and under Article III, Section 32, of the Constitution of Pennsylvania.
*93I would affirm the order of the Commonwealth Court setting aside the order of the Secretary of the Department of Labor and Industry.
JONES, C. J., joins in this dissent.. Act of July 14, 1971, P.L. 221, 43 P.S. § 255.1 (Supp.1974).
. Act of May 20, 1926, Ch. 347, § 1, 44 Stat. 577, as amended, 45 U.S.C. § 151 et seq. (1971).
. Constitution of the United States, Art. 6 clause 2.
. The Supreme Court’s statement of these indicia of congressional intent was as follows:
“The scheme of federal regulation may be so pervasive as to make reasonable the inference that Congress left no room for the States to supplement it. [citations omitted]. Or the Act of Congress may touch a field in which the federal interest is so dominant that the federal system will be assumed to preclude enforcement of state laws on the same subject, [citation omitted]. Likewise, the object sought to be obtained by the federal law and the character of obligations imposed by it may reveal the same purpose, [citations omitted]. Or the state policy may produce a result inconsistent with the objective of the fed*87eral statute.” Rice v. Santa Fe Elevator Corp., 331 U.S. 218, 230, 67 S.Ct. 1146, 1152, 91 L.Ed. 1447, 1459 (1947). (Emphasis added).
. See generally Title 45 of the United States Code and the many statutes embraced therein governing railroads in interstate commerce.
. The broad purposes of the Railway Labor Act as set forth by Congress in § 2 of the Act, 45 U.S.C. § 151a are as follows:
“The purposes of the chapter are: (1) To avoid any interruption to commerce or to the operation of any carrier engaged therein; (2) to forbid any limitation upon freedom of association among employees or any denial, as a condition of employment or otherwise, of the right of employees to join a labor organization; (3) to provide for the complete independence of carriers and of employees in the matter of self-organization to carry out the purposes of this chapter; (4) to provide for the prompt and orderly settlement of all disputes concerning rates of pay, rules, or working conditions; (5) to provide for the prompt and orderly settlement of all disputes growing out of grievances or out of the interpretation or application of agreements covering rates of pay, rules, or working conditions.” 45 U.S.C. § 151a (1971).
. Section 6 of the Railway Labor Act, 45 U.S.C. § 156, provides as follows:
“[Notice of Intended Change in Agreements affecting Rates of Pay, Rules, or Working Conditions.] Carriers and representatives of the employees shall give at least thirty days’ written notice of an intended change in agreements affecting rates of pay, rules, or working conditions, and the time and place for *89the beginning of conference between the representatives of the parties interested in such intended changes shall be agreed upon within ten days after the receipts of said notice, and said time shall be within the thirty days provided in the notice. In every case where such notice of intended change has been given, or conferences are being held with reference thereto, or the services of the Mediation Board have been requested by either party, or said Board has proffered its services, rates of pay, rules, or working conditions shall not be altered by the carrier until the controversy has been finally acted upon, as required by section 5 of this act, by the Mediation Board, unless a period of ten days has elapsed after termination of conferences without request for or proffer of the services of the Mediation Board.”
. A change to a weekly pay system was proposed by means of a Section 6 notice by predecessor organizations to United Transportation Union, the present appellant, in 1959. Negotiations pursuant thereto resulted in a change from a semi-monthly basis of payments to a bi-weekly basis. This basis has continued to date.
. The reliance of the majority opinion, ante, page 10, on Terminal Railroad Association v. Brotherhood of Railroad Trainmen, supra, is misplaced. The Supreme Court there distinguished between “differences that threaten continuity of work” and those which involve “conditions that threaten the health or safety of workers.” Id., at 6, 63 S.Ct. at 423, 87 L.Ed. at 577. The clear implication is that disputes which do not involve health or safety must be resolved through the processes of the Railway Labor Act. This reading of Terminal Railroad Association is borne out by the reference to that case in California v. Taylor, supra at 560, n. 8, 77 S.Ct. 1037, at 1041, 1 L.Ed.2d at 1039, n. 8. After citing cases upholding the supremacy of federal statutes relating to railroads in interstate commerce, the Court cites Terminal Railroad Association, for the proposition that “the Railway Labor Act did not preclude a State from establishing minimun health and safety regulations in the interests of railway employees. That case did not concern a conflict between federally protected collective bar*91gaining and inconsistent state laws.” The decision has thus been limited to the facts there involved; the unnecessarily broad language relative to preemption used by Mr. Justice Jackson in his opinion and relied on by the majority here was dictum.