This paper presents a prototype real time clock ensemble designed for semi-autonomous operation at unmanned Loran-C radionavigation transmitting stations. This clock is designed to mitigate a doomsday scenario where all space-based timing assets are lost. It is implemented using three free-running commercial cesium oscillators, a traditional measurement system, and an Auxiliary Output Generator (AOG) phase-locked to the weighted mean of the cesium ensemble. A relatively inexpensive rubidium oscillator is used ...