don't tell anyone but these are 81ft long each lol

Available in 3 different colors
-Green (download this post)
-Red
-White
And if you want a longer version of the green one (as seen in 1st pic), you can try over 1,000 parts here

Info
Center flows are used worldwide for carrying products that cannot be exposed to climates, but fill like a liquid. These North American styled ones take woodchips/pulp, grain, and crushed rocks and ores. Occasionally they may be used for sand.

Info but SP
The cars are only 101 parts each. Altogether, it's 506 parts (including cockpit). The bodies have drag disabled, to reduce lag. You might notice some part saving ideas, such as using parachutes as bays (underneath the cars), magnets for top doors, and using rotators as supports for the walkways on the roof.

How to use
-Spawn as a locomotive in a railway map. You can use these as long as it is a powered train.
-Go to spawn AI, and select this train. Make sure it's on the correct track.
-Activate the locomotive's magnets and couple.
You can now drive your train.

Trains in the screenshots can be found on this forum post.

Enjoy!