In August, all Alaska Railroad locomotives used in yard and switch service started using oscillating yellow warning beacons which had been mounted on top of locomotive cabs in an effort to prevent crossing accidents in the yard areas.  They have proved so successful that a program is underway to equip all locomotives with the warning device.  At present, the beacons are not used when the locomotives are in road service, and will not be until such time as all locomotives are so equipped.