Action0/Vehicles/Trains

Action 0 properties for trains

Action 0 - Properties for train vehicles

Defining properties of train vehicles.

{maketoc}

-=Properties=-

||Number|Version|Size|Description|Available for articulated parts

05| |B|Track type (see below)|should be same as front

08| |B|AI special flag: set to 1 if engine is 'optimized' for passenger service (AI won't use it for other cargo), 0 otherwise|no

09| |W|Speed in mph*1.6 (see below)|no

0B| |W|Power (0 for wagons)|should be zero

0D| |B|Running cost factor (0 for wagons)|should be zero

0E| |D|Running cost base, see below|should be zero

12| |B|Sprite ID (FD for new graphics)|yes

13| |B|Dual-headed flag; 1 if dual-headed engine, 0 otherwise|should be zero also for front

14| |B|Cargo capacity|yes

15| |B|Cargo type, see column 3 (type B) in CargoTypes|yes

16| |B|Weight in tons|should be zero

17| |B|Cost factor|should be zero

18| |B|Engine rank for the AI (AI selects the highest-rank engine of those it can buy)|no

19|1|B|Engine traction type (see below)|no

1A|1/(f)|B/B*|Not a property, but an action: sort the purchase list.|no

1B|6|W|Power added by each wagon connected to this engine, see below|should be zero

1C|6|B|Refit cost, using 50% of the purchase price cost base|yes

1D|6|D|Bit mask of cargo types available for refitting, see column 2 (bit value) in CargoTypes|yes

1E|6|B|Callback flags bit mask, see below|yes

1F|(a)|B|Coefficient of tractive effort|should be zero

20|(b)|B|Coefficient of air drag|should be zero

21|2|B|Make vehicle shorter by this amount, see below|yes

22|6|B|Set visual effect type (steam/smoke/sparks) as well as position, see below|yes

23|6|B|Set how much weight is added by making wagons powered (i.e. weight of engine), see below|should be zero

24|(c)|B|High byte of vehicle weight, weight will be prop.24*256+prop.16|should be zero

25|(c)|B|User-defined bit mask to set when checking veh. var. 42|yes

26|(c)|B|Retire vehicle early, this many years before the end of phase 2 (see Action0General)|no

27|(d)|B|Miscellaneous flags|partly

28|(d)|W|Refittable cargo classes|yes

29|(d)|W|Non-refittable cargo classes|yes

2A|(e)|D|Long format introduction date|no||

Version codes:

||Code|Version

(a)|2.0.1 alpha 19

(b)|2.0.1 alpha 27

(c)|2.0.1 alpha 44

(d)|2.0.1 alpha 58

(e)|2.5 r1210, OpenTTD r7191

(f)|OpenTTD r13831||

-=Comments=-

Track type (05)

Set track type of vehicle: 0 = rail, 1 = monorail, 2 = maglev. For setting the appropriate traction type, see prop19.

In OpenTTD, if a rail type translation table is loaded, this property is an index into the table instead.

Speed (09)

Train speed is in units of mph*1.6, i.e. approximately km/h.

For wagons, this value is only used if the "wagonspeedlimit" switch is on, and it limits the speed of the train to that of the lowest wagon speed.  This limit is ignored for wagons with a livery override for the current train, so that train sets always get their max speed from the engine's max speed.

For wagons, a value of 0 means "default" (which depends on cargo type and date of introduction), and FFFF means no limit.

Power (0B)

The power of the engine, in HP.

A value of 0 means that the vehicle will be a wagon, otherwise it will be an engine.

Running cost base (0E) and factor (0D)

TTD calculates all costs by multiplying a 32-bit base amount with an 8-bit factor.  The base amount is changed according to inflation, whereas the factor remains constant.

For the running costs of train vehicles, the following base amounts are available depending on the vehicle type (the value here is a pointer into TTD's memory where the actual amount is stored):

||Type|Value|in little-endian notation

Steam engines|4C30|30 4C 00 00

Diesel engines|4C36|36 4C 00 00

Electric engines|4C3C|3C 4C 00 00

Wagons|0|00 00 00 00||

Theoretically, you could use pointers to other base amounts available in TTD, but these are the numbers TTD uses for train vehicles.

The following are some real values for maintenance costs depending on the setting of the above two factors.  This value is correct for medium difficulty, but increases and decreases for hard and easy difficulties respectively.  These are the costs of a new game starting in 1921, because they obviously increase with inflation over time (unless noinflation is turned on).

Running cost base 4C30 (steam)

||Running cost factor|Maintenance cost

01|$ 42

10|$ 700

20|$ 1.400

80|$ 5.600

A0|$ 7.000

FF|$ 11.112||

Running cost base 4C36 (diesel)

||Running cost factor|Maintenance cost

01|$ 40

10|$ 650

20|$ 1.300

80|$ 5.200

A0|$ 6.500

FF|$ 10.318||

Running cost base 4C3C (electric)

||Running cost factor|Maintenance cost

01|$ 36

10|$ 600

20|$ 1.200

80|$ 4.800

A0|$ 6.000

FF|$ 9.524||

Cost factor (17)

The cost factor is a bit-coded value which determines how expensive an engine is. There is no distinction between steam, diesel or electric engines, they all use the same cost factor. The table below gives you some values to use for finding the right price for your engines.

||Cost factor|Price

01|$ 3.124

10|$ 50.000

20|$ 100.000

80|$ 400.000

A0|$ 500.000

FF|$ 796.874||

Engine traction type (19)

This sets the traction type of a train engine, i.e. whether it is powered by steam, diesel, electric, monorail or maglev technology.  It also sets the corresponding sound effect of the engine, and if property 22 is not set, the visual effect as well.

The following ranges are available (and it does not matter which value you pick):

||Values|Traction type

00..07|Steam

08..27|Diesel

28..31|Electric

32..37|Monorail

38..41|Maglev||

Default value is 00, i.e. steam. For setting the appropriate track type, see prop05.

In OpenTTD, if a rail type translation table is loaded, setting this property does NOT alter the track type.

Sort vehicle list (1A)

This property is an extended byte in OpenTTD since r13831!

This is not a property as such, but an action.  It forces TTDPatch to shuffle the vehicle this "property" is being set for in front of the vehicle with the given value of the property.  The order of this list is only used in the train purchase window.

For example, setting prop. 1A for vehicle 09 to a value of 07 would lead to the following internal list: ... 05 06 09 07 08 0A 0B ...

This property can not simply be overwritten, because the list is already shuffled when trying to do so.  It is possible to reset the list to its original order with a special action 0 that has num-info set to 0, and only sets property 1A for trains:

-+00 00 01 00 00 1A+-

Resetting the list should however only be done by sets that contain replacements for all train vehicles.

Powered train wagons (1B and 23, see also 22)

Normally, train wagons are unpowered in TTD, and if you set property 0B to a non-zero value, they become engines instead.  Therefore, to model real-life trains where wagons have power, a different mechanism is needed.

To make train wagons powered, you set property 1B of the engine instead of the wagon. This determines how much power each wagon adds to the train when attached to this engine. This only applies to wagons with a graphics override for this engine as well.  This means that for example passenger wagons (with an override) will add power, but coal wagons (with no override) will not.

In addition to adding power, these wagons are also heavier by the amount set in property 23.

Callbacks (1E)

For trains, the following callbacks have to be enabled by setting the corresponding bit in property 1E (certain other, not as frequently used callbacks are available without setting a bit here):

||Bit|Value|Variable 0C value|Callback

0|1|10|Powered wagons and visual effect

1|2|11|Wagon length

2|4|12|Load amount

3|8|15|Set refitted capacity

4|10|16|Build articulated engines

5|20|19|show a suffix after the cargo type name

6|40|2D|Select color mapping for vehicle

7|80|33|Sound effect callbacks||

Bit is the bit you have to set, you do this by adding all the values for all the bits. Variable 0C value is what variable 0C will be set to, for checking it in the variational action 2 for callbacks.

Callbacks 1D (Can wagon be attached?), 23 (Additional text in purchase screen), 31 (Start/stop check), 32    (32-day callback), 34     (Autoreplace vehicle selection) and 36 (Change Vehicle Properties) do not need a bit to activate them, they are always active and will be used if defined in the action 3/action 2 chain.

Coefficient of tractive effort (1F)

This cofficient sets what fraction of the vehicle weight is equal to the maximum tractive effort.  This includes the effect of having some unpowered axles, as well as the coefficient of friction that is available.

Theoretically, this value should be calculated by taking the ratio of adhesive weight W{SUB()}adh{SUB} (i.e. the vehicle weight that rests on powered axles) times the coefficient of friction µ between the wheels and the rails to the total vehicle weight W, times 255, and convert to hex:

prop. 1F = HEX 

[[Action0Cargos#Cargo_classes_16_|action0 cargos]] page for bits and classes defined so far.

Note that cargo types may belong to several classes. This is the reason for making two properties, an additive and a subtractive one, because this way a vehicle can be specified to be refittable to, for example, all express cargo that does not require refrigeration (i.e., from the default cargos, no food).

For the cargo types added in this way, the vehicle will probably have no specific graphics (in [[Action3|action 3]]) to show the cargo load.  In this case, the default will be used, which should therefore be sufficiently generic-looking if possible. However, using [[VarAction2Vehicles#Vehicle_cargo_info_47_|vehicle variable 47]] you can at least select the graphics most appropriate for the cargo type's class.

==Long format introduction date (2A)==

Set the vehicle introduction date, in days since the year 0. This takes account of leap years; dividable by 4, but not 100 unless 400. A start date of 1920-01-01 is obtained with a value of 701265 (51 B3 0A 00). This property must be set after property 00 to take effect. In TTDPatch, dates after 2044 will be limited to 2044.

-=Example=-

Below is an example of what a real Action 0 pseudo-sprite could look like for a train engine.

(A basic version)

<pre>10 * 14  00 00 03 01 02 09 C0 00 0B D8 0E 12 FD

||Bytes|Meaning

10|<Sprite-number>

14|<Length>: of the action in bytes; start counting at 0 (<action>)

00|<action>: sets this pseudo-sprite to function as action 0

00|<Feature>: In this case Train

03|<Num-props>: 3 Properties to change

01|<Num-info>: 1 vehicle ID to make changes to

02|<ids...>: vehcile ID (02 - Ploddyphut Choo-Choo)

|Properties

09|<Speed>

C0 00|<Value>: Value for Speed (192 Km/h)

0B|<Power>

D8 0E|<value>: value for Power (3800 HP)

12|<Sprite ID>

FD|<value>: FD for new graphics||