N4 supports positions 1 to 11 on up to three 40' chassis for a truck. The numbering scheme for the supported positions has the following rules:
20' positions are odd numbers starting behind the truck cab at position 1 and counting up for each 20' of chassis, such as 3, 5, and so on.
40' positions are comprised of two 20' positions and are the even number that falls between the two 20' positions. For example, 40' position 2 takes up the same space as 20' positions 1 and 3.
40' containers are always in even positions. However, 20' containers can be placed in either odd positions or in an even position when centered on a 30' chassis or inside a 40' position.
Because the first and last 20' position on each chassis in an odd position, you must skip an even position when moving from one chassis to the next. For example, a truck with two 40' chassis has odd 20' positions 1 and 3 on the first chassis and 5 and 7 on the second. Therefore, the even 40' positions are position 2 on the first chassis and position 6 on the second, skipping position 4.
A 30' chassis is treated similar to a 40' chassis, in that it also has three possible positions. Because you can place a 20' container in a fore, centered, or aft position, it has the same three possible positions as a 40' chassis even though it cannot carry a 40' container.
For example, a truck with one 40' chassis has the following possible positions:
A 20' container closest to the truck cab is in position 1.
A 40' container or a 20' container centered on the chassis is in position 2.
A 20' container farthest on the chassis is in position 3.
To enable a clerk to enter the position of a container on a truck in a gate form, add the Pos on Truck field to the appropriate trans type (on page 1) forms.
The following illustration displays three example truck configurations and the positions on the containers on each truck.
In the above illustration:
Truck A has three 40' chassis. The first 20' container behind the truck cab is in position 1 and the second 20' container is in position 3. Position 4 is skipped when moving from the first to second chassis. The 20' container on the second chassis is in position 6 since it is centered on the chassis. If this container was instead fore or aft on this chassis, it would be in position 5 or 7 respectively. Position 8 is skipped when moving from the second to third chassis. Therefore, the 40' container on the third chassis is in position 10.
Truck B has a 20' chassis followed by a 30' chassis and then a 40' chassis. The first 20' container behind the truck cab is in position 1. Position 2 is skipped when moving from the first to second chassis. The 20' container on the second chassis is in position 4 since it is centered on the chassis. If this container was instead fore or aft on the chassis, it would have been in position 3 or 5 respectively. Position 6 is skipped when moving from the second to third chassis. Therefore, the 40' container on the third chassis is in position 8.
Truck C has two 60' chassis. The first 40' container behind the truck cab is in position 2. The 20' container on the first chassis is in position 5 since the previous 40' container uses up positions 1 and 3. Position 6 is skipped when moving from the first to second chassis. Therefore, the three 20' containers on the second chassis are in positions 7, 9, and 11. If the third chassis instead had two 20' containers that were centered in 40' positions, then they would be in positions 8 and 10.