"Motor" container

The Motor container is a top-level config.txt file entry used by Enginespec and Steam Enginespec assets.

Supported Tags

The Motor container supports the following tags. Each tag is show here with its default value.

motor
{
    resistance                     1.7
    adhesion                       5.0
    maxvoltage                     600.0
    maxspeed                       33.3
    brakeratio                     55000
    max-accel                      3500
    max-decel                      9000
    throttle-notches               8
    axle-count                     6
    surface-area                   80.0
    moving-friction-coefficient    0.03
    air-drag-coefficient           0.00017
    full-throttle-speed            33.0
    driving-wheel-weight-ratio     1.0
}

resistance

Type: Decimal

Desc: Not used

adhesion

Type: Decimal

Desc: Not used

maxvoltage

Type: Decimal

Desc: Voltage to traction motors. This is used to scale the ammeter displayed in the cab. (Power is volts times amps - increasing the voltage means reducing the ammeter...)

maxspeed

Type: Decimal

Desc: Maximum speed in DCC mode.

brakeratio

Type: Decimal

Desc: Coefficient between the pressure in brake cylinder and the brake force.

max-accel

Type: Decimal

Desc: Accelerative force available in DCC mode. Note - this is a force, not a rate of acceleration. The rate of acceleration will depend on the mass of the train as well.

max-decel

Type: Decimal

Desc: Decelerative force available in DCC mode. Note - this is a force, not a rate of deceleration. The rate of deceleration will depend on the mass of the train as well.

throttle-notches

Type: Integer

Description: Specifies the number of throttle notches in the cabin. By default, all (non-steam) locos have 8 throttle notches, but this may be overridden with this tag. Note that this has no impact on train power output, unless the engine also enables the throttle-power-extended-notch-range or dynamic-brake-extended-notch-range options, and provides the relevant data in the power output graphs.

axle-count

Type: Integer

Desc: Number of axles on this vehicle. Used in rolling resistance calculations.

surface-area

Type: Decimal

Desc: Frontal surface area (sq ft) of vehicle. Used in air resistance calculations.

moving-friction-coefficient

Type: Decimal

Desc: Used in rolling resistance calculations.

air-drag-coefficient

Type: Decimal

Desc: Used in air resistance calculations.

full-throttle-speed

Type: Decimal

Desc: Obsolete- no longer used. (Previously: maximum speed with DCC throttle at 100%)

driving-wheel-weight-ratio

Type: Decimal

Desc: Ratio (between 0.0 and 1.0) of the weight of this vehicle bearing down on driven wheels. Used by steam locos only.

Resistance calculations

These calculations occur according to Davis formula:

R = (1.3·m + 29·axle-count) + moving-friction-coefficient·m·V + air-drag-coefficient·surface-area·V^2 + 20·m·G

R = total resistance in lb. including grade resistance
V = speed - mph
m = weight of the vehicle (tons)
G = % grade (upgrade +, downgrade -)