arm 1 NATIONAL RAILROAD ADJUSTMEMBOARD Award No. 6394
 SECOND DIVISION Docket No. 6201
 2-PT-CM-X72
 The Second Division consisted of the regular members and
 in addition Referee Irving R. Shapiro when award was rendered.

Parties to Dispute: ( (Carmen)

Dispute: Claim of Employes:










Findings:.

 The Second Division of the Adjustment Board, upon the whole record and all . the evidence, finds that:

 The carrier or carriers and the employe or employes involved in this dispute are respectively carrier and employe within the meaning of the Railway Labor Act as approved June 21, 1934.

 This Division of the Adjustment Board has jurisdiction over the dispute involved herein.

The Petitioner charges a violation of Rule 8, of the controlling Agreement, which Rule endeavors to provide means to equalize overtime between employees, and avers that claimants were deprived of overtime work opportunities and earnings stemming therefrom on three occasions.

 A careful reading of the record reveals that the dispute can be narrowed down to two statements. The Organization in its rebuttal, states:
 Form 1 Award No. 6394
 Page 2 Docket No. 62x1
 2-PT-CM-'72._.~
 "Thestatement submitted by the Carrier is true wherein the"Carrier
 states that it has always been the duty of the wreckmaster to be gang
 leader at all derailments; however, prior to July 5, 1970, the date that
 the first claim was initiated, acted in the capacity of wreclunaster. He
 supervised and directed the Carmen engaged in the rerailing operation
 only. He was not allowed to perform any duties of a Carman, unless he
 was selected from the overtime list in accordance with Rule 8 (b) of the
 Current Agreement. It has always been a Carrier policy to have the
 Wrecknaster at the scene of all derailments for this heretofore quoted
 purpose. However, on July 5, 1970, and thereafter, the Carrier took it
 on their own to arbitrarily change this long established practice, that
 they initiated themselves, and called one less Carman from the overtime
 call list, under Rule No. 8 and ordered the Wreckmaster R. E. Palmer to
 not only supervise and direct the operation, as was the procedure in the




Petitioner does not question the right of the Carrier to call oat the Wreckmaster for a rerailing job at times other than his regularly assigned hours. This obviously is an accepted exception to Rule 8 (b). Nor does the Petitioner object to the Wreckmaster's performing any and all Carmen duties at a derailment which occurs during his regularly assigned hours. The crux of its discontent is the Wreckmaster's performing other than supervisory functions when on overtime unless he had been chosen to work overtime by the Local Committee.

 It is fundamental in the determination of the meaning and intent of contract provisions that we ascertain the manner in which the parties have operated thereunder. We have accepted fact that without protest by the Organization, the Carrier called out the Wreckmaster for all derailments during and outside his assigned hours without referring to the Local Committee. We have a dispute as to whether when called to work outside his regular hours, he performed Carmen duties as well as directed the operation.

 Two well established concepts pervade most of our Awards on related problems. First, it is the function of Management to determine the size of the work force it requires to perform a specific job. Second, it is incumbent upon the complaining party to establish with probative evidence that the breach of the agreement, its intent and meaning, had occurred.

 If, as the Carrier states, there existed a practice whereby the Wreckmaster, properly called out for a derailment, performed all duties in connection with the rerailing, this was the accepted understanding of the application of Rule 8 with reference to this category of Carmen at the property. Saying that this was not so, does not make it not so: and Petitioner did not, in the record before us,
Form 1 Award No. 6394
 'tee 3 - Docket No. 6201
 2-PT-CM-t72

 ,port its contention in this regard, with more than an allegation. We are unable to resolve a question of fact with that which was afforded us and therefore must hold that the Petitioner failed to support the claim of a violation of Rule 8 as such Rule was adhered to and applied by the parties with reference to Wreckmaster's functions at a derailment at any time.

                        A W A R D


      Claim denied.


                        NATIONAL RAILROAD ADJUSTMELT BOARD By Order of Second Division


Attest: ef~c~
 Executive Secretary

 Dated at Chicago., Illinois, this 31st day of October, 19.720

 I