The basic document for traffic control at Ferrovias Guatemala is Authorization to Use the Track (Autorización Uso de Vía, a.k.a. Track Warrant). It is issued by a train dispatcher to the conductor through a cell phone on the engine. The authorization always expires in a station where the train meets another train (if there is no opposite train, then in a station where crews change or in a final destination). Once both conductors report their arrival, the dispatcher issues a new Authorization. The system is adopted from the U.S. (TWC - Track Warrant Control). Unlike Europe, trains do not follow a fixed schedule and do not have numbers (recipient of Authorization is identified by engine number and direction - see "Loc. 901 Norte" in the header).
Logic of the TWC system in the US is described in detail by Carsten Lundsten. Official rules are included in the General Code of Operating Rules. The same or very similar rules are in place in Guatemala.
© Jan Peula, 2004