[CB: ]

Couple Base, Couple Left, Couple Right

One picture is coupled to another so that one part of the second picture overlaps the first.

These commands are the only commands that can be used to expand a picture in a horizontal direction.  They were introduced originally to couple trailers to trucks, but also usable to couple special railway vehicle for heavy loads etc.

[CL:] and [CLB:] extends the picture by placing the new picture to the left, behind the original picture.

[CLF:] extends the picture by placing the new picture also to the left, but before the original picture.

[CR:] and [CRB:] extends the picture by placing the new picture to the right, behind the original picture.

[CRF:] extends the picture by placing the new picture to the right, before the original picture.

The parameters <BaseX> and <AddX> specify a contact point in the vehicle pictures.  The parameter <BaseX> is the position of the contact point, measured from the side in the original picture ( CL : left side, CR : right side).  The parameter <AddX> specifies the position of the contact point in the overlay picture measured from the edge which meets the base picture (in the case of the [ CL:] and [CLF:] commands  from the right, in the case of the [CR:] and [CRF:] commands from the left side).  The overlay picture is positioned so that both contact points overlay each other: new width  = original width + overlay width - <BaseX> - <AddX>.

It is understood that the contact point in the case of a tractor trailer is the "fifth wheel" or coupling mechanism between tractor and trailer.  Because one can combine many different tractors with just as many trailers and the contact point is always the same, it is possible to predefine this point by using the command [CB: ].  If the vehicle has the modifier [CB: ] in front of the modifiers [CL:] and [CR:], the default value of the parameter <BaseX> is the value specified in [CB:] (if you omit the  parameter value <BaseX> the value of [CB:] will be used instead, however, you can also input other values as well).  If an overlay picture has a [CB:] parameter in its macro in the Stock List then the default value for <AddX> is set to this value.

The <Y> parameter specifies the vertical position of the added picture. If the parameter is not given, the extending picture's macro is looked for a [CY:] modifier. If the modifier is given, the parameter therein is used to place the additional picture. If neither values are given, the extending picture is placed to 0 - beside the original picture. Placing oversized loads on a truck you should specify the heigth rather at the track.

Trucks will be extended always on one side, but other picture could be extended on both sides, with different contact points. One can define separate contact points for extending to left by the [CBL:] modifier, and for extending to right by the [CBR:] command. Similarly, the contact point of the added picture can differ, if it is used for extending it to left or to right. If the new picture is used to extending to left, then its [CBR:] modifier is checked (beside the [CB:] modifier) for determining it's contact point distance. It is not a typo - remember, the extending picture's right side will be placed to the left side of the extended picture, so, the right contact point distance of the extending picture is needed.

After the picture is extended, on the extended side it inherits the contact point distance of the extending picture for possible further extensions. Of course, if the extending picture has different contact point distances by separate [CBL:] and [CBR:] modifiers, then the value of the appropriate side is used (extending to the left the left side contact point is used, given by the extending picture's [CBL:] modifier).

One can also use this command to place loads on vehicles where the load exceeds the horizontal length of the original picture.  If one had a load which was so large that it needed to span two or more vehicles (for example, some long steel forms and industrial loads are shipped spanning three flat cars) the vehicle pictures should first be combined using the couple command (in this case the overlap values <BaseX> and <AddX> should be 0 as the vehicles couple normally). Then the load can be placed onto the combined vehicles as normal.

One can use this command to stretch the horizontal distance of a vehicle by using this command multiple times.  Please remember that the combined vehicle possesses the macros and characteristics of the original picture that serves as the base for the expansion.  The overlay vehicles only contribute their pictures, not any of their macros and other characteristics. After processing this modifiers one can place further modifiers in the vehicle macro - but remember, this following macros will use the resulting, extended picture for their coordinate parameters. If a picture is extended to the left, and a following modifier for example wants to place something  on the picture by an [O:] command, on should use coordinates of the resulting extended picture, not the coordinates of the original picture.