Action0/Vehicles/Ships

Action 0 - Properties for road vehicles

Defining properties of road vehicles.

Properties

Number	Version	Size	Description	Available for articulated parts
08		B	Speed in mph*3.2	no
09		B	Running cost factor	should be zero
0A		D	Running cost base, see below	should be zero
0E		B	Sprite ID (FF for new graphics)	yes
0F		B	Capacity	yes
10		B	Cargo type, see column 3 (type B) in CargoTypes	yes
11		B	Cost factor	should be zero
12		B	Sound effect: 17/19/1A for regular, 3C/3E for toyland	no
13	2	B	Power in 10 hp, see below	should be zero
14	2	B	Weight in 1/4 tons, see below	should be zero
15	2	B	Speed in mph*0.8, see below	no
16	2	D	Bit mask of cargo types available for refitting (not refittable if 0 or unset), see column 2 (bit values) in CargoTypes	yes
17	6	B	Callback flags bit mask, see below	yes
18	(a)	B	Coefficient of tractive effort	should be zero
19	(a)	B	Coefficient of air drag	should be zero
1A	(a)	B	Refit cost, using 25% of the purchase price cost base	yes
1B	(b)	B	Retire vehicle early, this many years before the end of phase 2 (see Action0General)	no
1C	(c)	B	Miscellaneous vehicle flags	partly ("tram" should be same as front)
1D	(c)	W	Refittable cargo classes, see train prop. 28	yes
1E	(c)	W	Non-refittable cargo classes, see train prop. 29	yes
1F	(d)	D	Long format introduction date	no
20	(e)	B*	Sort the purchase list	no
21	(f)	B	Visual effect	yes

Version codes:

Code	Version
(a)	2.0.1 alpha 30
(b)	2.0.1 alpha 44
(c)	2.0.1 alpha 58
(d)	2.5 r1210, OpenTTD r7191
(e)	OpenTTD r13831
(f)	OpenTTD r21240

Comments

Running cost base (0A) and factor (09)

TTD calculates all costs by multiplying a 48-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 road vehicles, the following base amounts are available:

Type	Value	in little-endian notation
Road vehicle running cost base	4C48	48 4C 00 00

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

Cost factor (11)

The cost factor is a bit-coded value which determines how expensive a vehicle is. The table below gives you some values to use for finding the right price for your vehicles.

Cost factor	Price
00	$ 0
01	$ 108
10	$ 1,750
20	$ 3,500
80	$ 14,000
FF	$ 27,890

Realistic acceleration properties (13, 14, 15)

TTDP uses these properties only if road vehicles are set to realistic acceleration in the NewCurveAndMountainHandling switch. They are ignored otherwise.

OpenTTD uses these properties always, if they are defined and gives the speed defined here precedence over the one defined in property 08.

Using property 15 to set the speed, it is possible to achieve speeds larger than 80 mph (127 km/h), to which property 08 is limited. When setting property 15, always set property 08 as well, so that the vehicle works reasonably well whether realistic acceleration is turned on or off. If property 15 is not set, the value from property 08 is used instead.

Callbacks (17)

For road vehicles, the following callbacks have to be enabled by setting the corresponding bit in property 17 (certain other, not as frequently used callbacks are available without setting a bit here):

Bit	Value	Variable 0C value	Callback
1	2	11	Wagon length
2	4	12	Load amount
3	8	15	Set refitted capacity
4	10	16	Build articulated vehicle
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.

Coefficient of tractive effort (18)

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.

For a value of FF, the tractive effort is equal to the vehicle weight, for 80, it is half, and so on.  If not set, a default of 4C is used, for a fraction of 0.30, corresponding to Wadh=W and a coefficient of friction of 0.30, which is the value used by the patch before 2.0.1 alpha 19.

Coefficient of air drag (19)

This property sets the air drag coefficient c2 used for the realistic acceleration model, from 01 (no airdrag) to FF (most air drag) in arbitrary units.  00 means to use the default value that depends on the top speed (to simulate the fact that high-speed engines are more streamlined).

The default values are the following:

top speed (mph/1.6)	<16	16	24	32	48	64	96	128	192	256	...
c2	192	128	96	64	48	32	24	16	12	8

For higher speeds, the series is continued in the same manner.

Air drag in Newtons will then be c2*v*v with v in m/s, although it is probably futile to attempt to make c2 a realistic number due to the lack of TTd's consistent scaling.  If a vehicle doesn't reach its historical top speed, you might try setting prop. 19 one or two higher than the default above, otherwise it's probably a good idea to leave it at the default.

Miscellaneous flags (1C)

This is a bit mask, with the following bits:

Bit	Value	Meaning
0	1	Vehicle is a tram/light rail vehicle and requires tram tracks to operate
1	2	Uses two company colors

Long format introduction date (1F)

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.

Sort vehicle list (20)

See sort vehicle list for trains for details.

Visual effect (21)

See the equivalent train property for information about the meaning of all bits. There is no default effect for road vehicles, therefore values of 00..0F will show no visual effect. Bit 7 (disable wagon power) currently has no meaning and should be left at 0.