BATTLEFIELD CALCULATIONS
Section I. MOVEMENT PLANNING
8-1. GENERAL
An effective corps or division planner must understand how large corps and divisions are, the amount of space they may occupy, and the considerations for moving them under varying circumstances.
Moving a typical corps by tactical road march entails moving at least 25,000 vehicles, assuming the corps has three divisions, an ACR, and supporting troops. The corps would occupy road space of 2,500 kilometers if it marched at the normal interval of 100 meters between vehicles (10 vehicles per kilometer), even without gaps between march units and serials. Pass time at 25 kilometers per hour would be more than 4 days.
To conduct tactical operations, the corps must march on multiple routes at the greatest possible speed, making the most economical use of road space. Economizing road space requires greater vehicle density on the routes in use, a function of shorter intervals between vehicles and minimal gaps between march units and serials. Increasing the number of routes adds flexibility and speed. Condensing intervals and gaps increases risks.
The corps can shorten its movement time and accelerate its deployment by marching in division columns with four routes for each of two leading divisions and by:
Moving at a daylight rate of march of 30 kilometers per hour (kmph).
Maintaining a 50-meter (m) interval between vehicles.
Limiting gaps to 2 minutes between march units and 5 minutes between serials (1,000m and 2,500m at 30 kmph). On eight routes at that interval and speed, the corps column length and pass time become manageable, and divisions can deploy to fight in a reasonable amount of time.
Under these conditions, the 25,000 vehicles of the corps would occupy about the same total road space of 2,500 kilometers (1,200 km of occupied road space plus 1,300 km of gaps). Distributed over eight routes, the average corps column would be only 320 kilometers long and would pass in 10.5 hours at 30 kilometers per hour. A reinforced division (6,000 vehicles) marching on four routes would average 155 kilometers per column and would pass in just over 5 hours.
8-2. ARMORED DIVISION CONDUCTING A TACTICAL ROAD MARCH
a. Total wheeled and tracked vehicles. Total vehicles in a division = 5,314. (Trailers, aircraft, and vehicles that would probably or normally move by lowbed (bulldozers, forklifts, etc) were not counted.)
b. Road space. For an entire armored division to conduct a tactical road march, with 100 meters from the front of one vehicle to the front of the next vehicle and no considerations for march units and serials, the division requires 531 kilometers of road space. If the division moves on two routes, it requires 265 kilometers of road space per route.
8-3. ROAD MARCH PLANNING FACTORS
Movement formulas are applied to known distance, rate, and time data to derive information necessary to prepare a time schedule. The time schedule is used to regulate departures and arrivals of march elements.
a. Time and distance relationship. Relationships between time and distance are the basis for march planning. The planner determines how far the column is to travel (distance) and how long it will take to make the move (time). He must also know the space (the length of the column) the column will occupy on the route and the distance (gap) that separates march elements. Each term used for distance has its corresponding term for time. The length of the column in kilometers has an equivalent pass time in minutes. The relationship between time and distance and the average rate of march is shown in figure 8-1.
Figure 8-1. Time-distance relationships
b. Terms.
(1) March column- Elements using the same route for a single movement under control of a single commander.
(2) Serial - A major subdivision of a march column. Usually a battalion-sized unit. Usually 2 to 20 march units.
(3) March unit - A major subdivision of a serial. Usually a company-sized unit. Usually 10 to 24 vehicles.
(4) Arrival time - Head of column reaches the start point (SP).
(5) Clearance time - Tail of column reaches the release point (RP).
(6) Pass time (PST) - Time between when the first vehicle passes a given point and when the last vehicle passes the same point.
(7) Vehicle interval - Space between two vehicles (km).
(8) March unit gap (MUG) - Gap between the rear of one march unit and the front of the next march unit within a serial.
(9) March unit gap time (MUGT) - Time measured between the rear of one march unit and the front of the next march unit, within a serial, as they move past any given point.
(10) Serial gap (SG) - Gap between the rear of one serial and the front of the next serial within a march column.
(11) Serial gap time (SGT) - Time measured between the rear of one serial and the front of the next serial, within a march column, as the move past any given point.
(12) Time distance (TDIS) - The time required to move from one point to another at a given rate of speed.
(13) Road clearance time- The time it takes from when the first vehicle passes the SP to when the last vehicle passes the RP.
(14) Extra time allowance (EXTAL)- Time added to allow for the accordion effect during a movement and unplanned delays.
(15) Rate of march- Average number of kilometers traveled in any given period of time.
(16) Density - Average number of vehicles per kilometer.
(17) Speed - Planned velocity of the lead vehicle (kmph).
c. Formulas.
(1) Pass time (PST). (# of vehicles x 60 / (density x speed) ) + EXTAL + (# of SGs x SGT) + (# of MUGs x MUGT).
(2) Time distance (TDIS). Distance (km) / rate of march.
(3) Road clearance time. ((TDIS + 60) + PST) / 60.
(4) Extra time allowance (EXTAL). # of vehicles / 25.
(5) Rate of march. Distance / time.
(6) # of MUGs. # of march units - # of serials.
(7) # of SGs. # of serials - 1.