Form 1 NATIONAL RAILROAD ADJUSTMENT BOARD Award No. 29417
 THIRD DIVISION Docket No. MW-28307
 92-3-88-3-60
 The Third Division consisted of the regular members and in
 addition Referee Edwin H. Benn when award was rendered.

 (Brotherhood of Maintenance of Way Employes PARTIES TO DISPUTE:


STATEMENT OF CLAIM: "Claim of the System Committee of the Brotherhood that:

 (1) The Agreement was violated when the Carrier assigned junior MW Repairman P. Koch instead of MW Repairman J. Pikulak to a 'contract' MW Repairman position on the TracK Laying Machine (System File NEC-BMWE-SD-1672).





FINDINGS:
The Third Division D: 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.

Claimant holds a S.)uthern District seniority date of September 25, 1985, and an entered service date of June 2, 1982. P. Koch holds a Southern District seniority date of April 19, 1985, and an entered service date of January 24, 1984. Claimant and Koch were interviewed for a contract MW Repairman position on the Track Laying Machine which was advertised pursuant to Rule 89 of the parties' December 5, 1980 Memorandum of Agreement. That Rule provides, in pertinent part:
 Form 1 Award No. 29417
 Page 2 Docket No. W-28307
 92-3-88-3-60
 "I1. All positions and vacancies below the rank
 of General Foreman will be advertised to employes
 holding seniority on Corridor Units in accordance
 with the Rules of the Agreement. Bulletins adver
 tising these pnsttions will also be posted in places
 accessible to other employes covered by the said
 Agreement In order that such employes may, if they so
 desire, make application for advertised positions and
 vacancies.
 In tie fLLLing of positions advertised in accord
 ance with the drovision of the first paragraph
 hereof, the order of preference will be as follows:
 (:) From employes with seniority in the class L_n
 the unit in which position is advertised.
 _, From emDloyes with seniority in unit in
 wntch position is advertLsed 1n accordance
 wIth the ~uLes of the Schedule Agreement.
 r3, · rim emD2oyes with seniority in other
 Cirridor Uaits."

 Neither Siaimant nor Koch possessed seniority on the Track Laytn3 System. Further, neLther Claimant nor Koch was on a Corridor Seniority Roster. In short, literal application of Rule 89 did not establish a preference as between Cl.iimant possessed sufficient fitness and ability and awarded the position to Koch rather than Claimant based u on Koch's greater Southern District seniority. The Carrier further asserts t.^.at for nine years prior to this dispute positions were filled a this fas,lLon relying upon Southern (or Northern) ~Lstrict Seniority where ap?licants had no seniority on the Track Laying System or on a Corridor Seniority Roster.

 At best, ·he language in Rule 89 governing the awarding of positions to employees who do not possess seniority on the Track Laying System or who were not on any Corridor Seniority Roster is ambiguous. Rule 89 appears silent with respect to employees such as Claimant and Koch who hold no seniority under the designate contract construction, ambiguities in language can be resolved through the examination of custo-n and past practice between the parties. Here, the Carrier has sufficiently estaolished a past practice of reliance upon Southern (or Northern) Distri-,t seniority in such situations. Given Koch's greater Southern District arni-)rity, --he selection of Koch over Claimant therefore did not violate the .Agr·ement.
 Form 1 Award No. 29417
 Page 3 Docket No. MW-28307
 92-3-88-3-60




                          By Order of Third Division


Attest:

 40;Z;~itive Secretary

 Dated at Chicago, _Llinois, --.is 21st day of October 1992.