EXECUTING THE PLAN
Once the dispatcher has a basic strategic plan for the balance of the shift, usually and necessarily achieved in the first 30 minutes of the shift, the rest of the work is tactical. A passenger train may spend an extra 5 minutes at a station stop because of a large volume of baggage or express; a merchandise freight train may not be making the anticipated speed because of excess tonnage, engine failure, or other causes; a train may develop a defective car and stop to inspect, repair or even set out the car; a track inspector may find defective track structure and establish a speed restriction or even remove the track from service until it is repaired. Every piece of information the dispatcher receives, minutes or even seconds apart throughout the day, causes a quick recalculation of the similarity between the anticipated and actual locations of trains and how the new information affects all of the other trains and maintenance work. The 5 minutes later than anticipated that a train is passing a given point may well be the 5 minutes needed by an opposing train to advance one more station or for the requested maintenance work. That 5 minutes may also be significant in recalculating the rest of the trip as each time projection affects many others and must be accurate. Train dispatchers must be familiar with the physical characteristics of their territory and with the use of engineering maps known as profiles which contain detailed information on grade, curvature, bridges, tunnels, track configuration and other information. If there is no apparent specific reason for the difference between the dispatcher’s anticipated time and the actual time, the dispatcher may then use the knowledge of characteristics of the territory and of train dynamics to turn the actual running time into a new projection for the rest of the territory. Should the new projected time differ greatly from those originally anticipated, a completely new strategic plan for that period of time and distance affected by that train must be formulated.