"Motor" container

Revision as of 05:13, 22 September 2013

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
}

• Omit/delete as an illegal value in TRS2006∅

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, defined as the index of the last array-element with non-zero values in an array of arrays (container of sub-containers) —the dependent "Throttle-power" container.

• the contained arrays are the arrays-listing-paired-values (steps-of max speed and acceleration thrust force)— so the throttle-notches value is the last index# of an (nn+1)th element array listing elements made of other subcontainers (arrays of paired numbers which define points on a speed-power graph; and which has no fixed number of paired datum requirements; one engine spec might list 14, another 12 or 20).

Description: Can be viewed as the Number of "Power-is-applied" throttle-notches listed in the "Throttle-power" arrays of paired values (container) with power applied—not counting 'OFF' or zero power applied.

1. Not an total-elements or count-of-elements value, but the last legal index of the last element (nn) in an 1+nn-element array where the first element is idexed by 0 (zero).
   1. The first or Zeroth-indexed element has a value of zero, corresponding to Zero power applied, or Neutral.
   2. Value indicated must correspond to the number of NON-ZERO data arrays listed in the throttle-power container (a table of entries).
2. Each table element takes one index number in an array, so eight throttle notches (Diesel, no dynamic brakes) has nine array elements corresponding to a correct throttle-notches value of 8 (eight)—No Power, and eight Power Applied steps.
3. Dynamic brakes creates a doubling of elements and indexes, so a diesel with dynamic brakes will list 16 as the throttle-notches tag value, whilst the 'throttle-power' arrays will have 18 total elements —in this case: two zero power states, dynamic brakes engaged or not (normal) engaged states.

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:

Notes: TRS2006-SP0 reports this tag as an error in a "container-type 'motor'"

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.

Example motor container

TBD

Resistance calculations

These calculations occur according to Davis formula:

R = (1.3ˑm + 29ˑaxle-count) + moving-friction-coefficientˑmˑV + air-drag-coefficientˑsurface-areaˑV^2 + 20ˑmˑG

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