Parties to said dispute were given due notice of hearing thereon.

This case involves a claim for eight days of per diem allowance covering an eight rest day period (May 1 through and including May 8) and a single vacation day which the Claimant elected to take on May 9, immediately following his eight rest day period. The Carrier viewed the Claimant's use of a single vacation day as akin to voluntarily absenting himself, thereby denying the Claimant the per diem amount for his rest days as well as the single day of vacation taken. In support of this position, the Carrier asserts that historically, it has not paid the per diem allowance for rest days where the employee has taken less than 40-hour vacation increments, i.e., has taken "single-day vacations" on the work day immediately preceding or following the rest day period.

In support of the Claimants, the Organization asserts that the Carrier's action violated Rule 39(e) Rule 44(c) and Appendix X-1(2). The Organization also asserted that the Claimant's observance of scheduled vacation does not reasonably fit the express exceptions set forth in Rule 39(e) and accordingly, the Carrier's decision to withhold the per diem allowances violates the Agreement. This is so, the Organization maintains, due the fact that ". . . vacations of less than a full week are not always for the benefit of the employee but on many occasions the Carrier is happy to allow less than a full week of vacation so the position is not vacant for an entire week." Finally, the Organization maintains that Public Law Board No. 6302 Award 14 is not "directly on point" as the Carrier asserts because the facts in the instant matter are distinguishable from Award 14 and the pertinent Agreement provisions involved herein did not exist at that time.

In addition to the foregoing arguments, both parties make equity arguments: the Carrier asserts that per diem was specifically designed to defray employees' expenses when they are working away from home and is not to be treated as ordinary income for periods when they are at home. For its part, the Organization maintains that the per diem allowance is not sufficient to cover daily expenses and employees should not be deprived of income merely because they take contractuallypermitted vacations. Respectfully, the positions espoused by the Carrier and the Organization are irrelevant here. The only issue before the Board is whether per

diem payments for rest days are required by the Agreement when a vacation period of less than one week is taken adjacent to those rest days.

Following a careful review of the record, we find that the issue has been litigated by the Organization in the past without success.

Rule 39(e) as modified by the October 31, 1988 On-Line Service Agreement (OLSA) provides:

"On-line Service* - Employees assigned with headquarters on-line, as referenced in Rule 29, will be allowed a daily per diem allowance of $48.00 ($52.00 effective July 1, 2002 and $57.00 effective July 1, 2005) to help defray expenses for lodging, meals and travel.

The foregoing meal allowance will be paid for each day of the calendar week, including rest days, holidays and personal leave days, except it will not be payable for workdays on which the employee is voluntarily absent from service, or for rest days, holidays or personal leave days when the employee is voluntarily absent from service when work is available to him on the workday immediately preceding or the workday immediately following said rest days, holidays or personal leave days. No elimination of days for per diem allowances or vacation credits will occur when a gang is assigned a compressed work week, such as four (4) ten-hour days."

Concurrent with the signing of the OLSA, the parties entered into a Side Letter for the purpose of clarifying certain aspects of the OLSA's provisions. This Side Letter provides, in relevant part:

"[1]n reference to the amendments made this day to Agreement Rules 29, 30, 36 and 39. To help clarify some of the issues involved with the changes made, the following understandings will apply:

The Carrier asserts that most recent on-property Third Division Awards 39294, 39298, 39323, 39324, 39328 and 39331 have upheld the Carrier's recoupment and/or denial of rest day per diem allowances under substantially identical circumstances as present herein. Invoking the affirmative defense of collateral estoppel, the Carrier argues that these cited Awards are controlling precedent which the Board is compelled to follow. It therefore urges that the Board deny the instant claim.

Following our review of the facts and arguments in the parties' Submissions to the Board, we find from our close review of the entire record that the instant claim is indeed substantially identical to the cases considered by the Board as noted above. It is significant in reaching our decision in this case that the instant matter as well as those Third Division cases noted above is governed by the identical Agreement Rules. It is also significant that each of these decisions carefully considered the findings and conclusions in Award 14 of Public Law Board No. 6302 and, having done so, incorporated Award 14 thereby concluding that Award 14 was controlling precedent. Indeed, in Awards 39328 and 39331, the Board concluded:

"In Award 14, Public Law Board No. 6302 involving the parties to this dispute, the claimant took a single-day vacation on Monday, February 6, 1995 and was not paid a per-diem allowance for Saturday and Sunday. The PLB found that the claim turned on the interpretation of Rule 39(e) and held that `. . . per diem allowances where a one day vacation is taken must . . . be governed by the practice on the property. During handling on the property, the

We find the Board's stated conclusion applicable to this case and we therefore adopt it. In addition, it is noteworthy that each of the above cited Third Division Awards has consistently upheld the Carrier's practice of withholding per diem allowances on rest days when less than a full week's vacation is taken in conjunction therewith. Accordingly, given the Board's holdings in these substantially similar Awards together with the factual record before us, we rule that the Board must follow that line of established precedent as applied to the instant case pursuant to the doctrine of collateral estoppel. Collateral estoppel or issue preclusion, bars a party from relitigating an issue determined against that party in an earlier action, even if the subsequent action differs significantly from the prior one. Under collateral estoppel, findings of fact in a previous forum involving the same parties, the same issue of fact, and the same fact pattern will be given effect in later proceedings involving the same issues between the same parties. The application of this doctrine makes sense given the desire for stability in the Labor-Management relationship. Were the parties free to repeatedly submit the same issue to arbitral resolution, thereby essentially "shopping" for a different result, the common rule of

09-3-NRAB-00003-030426 (03-3-426)