Form 1 NATIONAL RAILROAD ADJUSTMENT BOARD Award No. 12032
 SECOND DIVISION Docket No. 11633
 91-2-88-2-119
 The Second Division consisted of the regular members and in
 addition Referee Lamont E. Stallworth when award was rendered.

 (Brotherhood Railway Carmen/Division of TCU PARTIES TO DISPUTE:

STATEMENT OF CLAIM:

 1. That under the current Agreement the Carrier violated Rule 10 when it failed to call Cayman B. Adams for overtime on January 4, 1987.

 2. That the Carrier be ordered to pay Cayman B. Adams eight (8) hours pay at the overtime rate.

 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 employes 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.

At the time this Claim arose, Claimant was regularly assigned as a second shift carman in the Carrier's John Sevier train yard at Knoxville, Tennessee. His assigned days were Friday through Tuesday, with Wednesdays and Thursdays off.

 On Sunday, January 4, 1987, a third shift carman, reported off due to illness at about 9:00 P.M. Therefore, the Carrier was required to call another carman to work overtime to cover his absence. The Carrier began by calling the carman who had worked the fewest hours of overtime according to a list maintained by the Carrier. That carman declined the work, as did the next four carmen in ascending order on the Carrier's list of overtime hours worked. Finally, the Carrier called a Cayman who was assigned as a second shift carman on the Carrier's repair track. This Cayman had the sixth fewest overtime hours according to the Carrier's list. He accepted the overtime assignment.
 Form 1 Award No. 12032,
 Page 2 Docket No. 11633
 91-2-88-2-119


carmen for this overtime assignment. The Organization asserts that an over
 time board is maintained in the train yard foreman's office, on which carmen
 assigned to the train yard record their availability and willingness to work
 overtime. According to the Organization, a separate overtime board is main
 tained for overtime assignments on the repair track. Claimant was listed
 first on the train yard overtime board.

 The first five employees offered the overtime assignment on January 4, 1987, were other carmen assigned to the Carrier's train yard. However, they were listed after Claimant on the overtime board. The Organization argues that Claimant should have been the first carmen offered the overtime assignment, and that no repair track carman should have been called until all train yard carmen on the overtime board had declined the work.

 According to the Organization, the Carrier violated Rule 10 of the Agreement. Rule 10 provides:








However, Rule 10 does not require that overtime assignments be offered in the
 order in which employees' names appear on the overtime board, or that all
 train yard carmen be called for overtime work in the train yard before any
 carmen assigned to the repair track is called. Rather, Rule 10 requires only
 that the Carrier undertake to distribute overtime hours equitably among car
 men. The procedure followed by the Carrier in this case fairly meets that
 objective.
 Besides alleging a violation of Rule 10, the Organization argues that
 the Carrier's procedure represented a unilateral abrogation of established
 practice between the parties. The Organization maintains that, until this
 case, the established practice involved calling employees in the order they
 are listed on the appropriate overtime board. However, the Organization's
 initial Claim on the property, filed January 13, 1987, did not assert that
 such an established practice existed. Even after the Claim was initially
 denied by the Carrier, the Organization's reply did not allege such an estab
 lished practice. The existence of such a practice was first asserted by the
 Organization in its February 13, 1987, appeal addressed to the Carrier's
 regional manager. On June 4, 1987, the Carrier replied to the Organization
 insisting that the Carrier had awarded the overtime assignment in this case as
 it always had in the past, by calling carmen beginning with the one with the
 least amount of overtime worked at that point. low
 Form 1 Award No. 12032
 Page 3 Docket No. 11633
 91-2-88-2-119
Because the Carrier's actions did not violate the letter or spirit of the applicable Rule in the Agreement, it was incumbent on the Organization to show that a practice had become firmly established between the parties which was breached. The Organization advanced such a Claim somewhat belatedly on the property, but it was promptly denied by the Carrier. The record does not establish what the traditional practice in fact had been. Since, however, it was the Organization's burden to prove its assertion in order for it to sustain its Claim, the lack of proof must be construed against the Claim. Accordingly, the Claim must be denied.

        Claim denied.


                          NATIONAL RAILROAD ADJUSTMENT BOARD

                          By Order of Second Division


Attest: d!sg~e'

      4a~ncyy J. D - Executive Secre ary


Dated at Chicago, Illinois, this 1st day of May 1991.