(Brotherhood of BSilway, Airline and Steamship Clerks,
 ( Freight Hamdlers, 8zpress and Station Employes
 PARTIES TO DISPUTE:
 (The Belt Railway Company of Chicago

1. Carrier violated the effective Clerks' Agreement when it failed to call Clerk R. Ostron, the inemabent of Position #551 for work on his rest day of September 30, 19781

 2. Ghrrier shall nor compensate Mr. Oatron for eight (8) hours' pay at the time and one-half rats of Position #551 far Saturday, September 30, 1978.

 OPINION O' BOARD: The Claimant is a regular incumbent of a 5 day position,
 with assigned hours of 8:00 sea* to 4:30 p.m., Monday
 through Friday.

 Prior to the incident under review, the employee represented by this Organization had been involved in a strike action against the Carrier, however the activity and picketing had terminated at 9:30 p.m. on Friday, September 29, 1978 and certain employes were scheduled to work on Saturday, September 30.

 The Carrier elected to have work performed on the Claimant's position on Saturday, September 30 but, according to the Organization, the work was not offered to the Claimant, even though he was available and willing to perform same. Instead, the Carrier called a junior employe to perform the work.

 According to the Claimant, utilization of the junior employe violated the Work on Unassigned Days Rule. In addition, the Claimant points out that he is senior to the employe who performed the work so that, in any event, he should have preference even if both employes perform similar duties.

 On the property, the Carrier took the position that when the decision was made to perform the work in question, the Claimant was "not available" for work. The Claimant asserts that the Employe's availability could not be known by the Carrier at the time, because it did not attempt to contact him. In response, the Carrier points out that on Friday, September 29, the employe who was used in lieu of the Claimant was on duty, even though the Organization was engaged in a strike against the Carrier, and he was asked to
 Award Number 23246
 Docket Number CL-23POT

 Page 2

 perform work on the following day at the close of the work day on September 29. Further, the C.rrier states that the fact that the picket line was eventually taken down late Friday was not something that could have been anticipated or known, other than by the Organization.

 We have considered the factual aspect of this case as it relates to the rather clear mandates of the agreement concerning work on unassigned days. Unquestionably, a Carrier must make a reasonable effort to call a proper employee and Award 22178 specifically determined that a Carrier may not make an assumption of unavailability. While the normal procedures may have been to notify employes on a Friday concerning Saturday work, we must recognize that those procedures would be more pertinent in a circumstance different than here. It may very well be that the timing of the circumstances might have precluded a lengthy exploration of manpower availability on the part of the Carrier; yet the record contains absolutely no indication that the Carrier took any effort to determine the Claimant's availability. Under those circumstances we are inclined to sustain the claim, but in doing so we stress that each such case of this nature must be determined on its own individual merits.

That the pasties waived oral hearing;

 That the Carrier and the Employes involved in this dispute are respectively Carrier and Employes within the meaning of the Railway Labor Actp as approved June 21, 1934;

the dispute involved herein; and

 That the Agreement was violated.

 Claim sustained.

 AITFST:

 Executive Secretary

 NATIONAL RAILROAD AWUS20NT HOARD
 By Order of Third Division

 Dated at Chicago Illinois this 31st day of march 19$1,