[INTRO]

This is my vision of a resourceful use of the train carts to build a small settlement around the station tower, which is converted to a minutemen outpost.  
Here they make use of the train carts all around, with most amenities inside them.
This is a scrappy settlement, settlers aren't as wealthy as many others, and most objects are worn and scrap made.

[MAIN FEATURES]

Item count: 679.

The main structure of the mod (train carts) is all vanilla, if you only want that (which was a bitch to setup), you don't need any other requirements, just place the furniture however you like.
The interior decor also isn't my best work, but it looks good enough considering minimal use of mod items and the vanilla item limit.

Minimal turret placement. I hate settlements with 100 turrets, they look bad, so here I just placed 3 strong M60 turrets, they are often enough to keep the place safe, but you might need to place a few more.    
You might also need to setup your own power source.

[ABOUT TRANSFER SETTLEMENT BLUEPRINTS]

Transfer Settlements is a mod that allows you to import settlements into external data files called BLUEPRINTS, which can be downloaded and imported into your game with the in-game setting holodisk. You NEED THIS.

[REQUIREMENTS]

First you need Transfer Settlements - Shareable Settlement Blueprints to import this settlement, along with the requirements bellow, if you dont want to use some of these, the assets will simply not show up, so you can skip a few, but it wont look like the images.

I have all DLCs, but they weren't used much.

I use Longer Power Lines at infinite length, not sure if this is needed or not.

Workshop Rearranged - might be required for everything to work, not sure
Sandbag Fortifications - Just a few placed on the towers.
Homemaker - Structure decor
cVc Dead Wasteland - Structure decor
CREAtive Clutter at Bethesda.net - Minor decor
M60 Light Machinegun - For the only turrets placed around.  
TTP's Settlement Objects - decor and furniture;
Workshop Decorations Pack - just decor
Settlement Supplies Expanded - Structure decor
Settlement Objects Expansion Pack -  just decor;
Crimsomrider's Unique Furniture - decor and furniture;
NorthlandDiggers Resources - Scavenging stations
Housekeeping - Scavenging Deluxe - Scavenging station

[SCRAPPING]

You can keep the tower, but not the items in there. You can keep everything inside the farm area and the fence around it. 
Everything else must go, including trees and all shrubs you can get rid of.
Keep the trains tracks of course, they look cool.