This is a scale model of a generic liquid-transport railroad tank car, where 1 stud's width on the model is equal to 15 scale inches, intended for use on an 8-wide Lego train. Using this scale, a minifig is about 6 feet tall while the car is 40 feet long, approximately 10 feet wide, and about 13.5 feet high, not including the trucks. The tank on its own is about 32 scale feet long. As this is my first attempt at a tank car - and my first design to make such heavy use of SNOT construction techniques, conincidently - I've simply called it the Mk. I. The car isn't functional by any means, and the only moving parts are in the trucks, but I'm nonetheless quite pleased with it.
The ladders aren't quite finished, there will be a small section below where they end now in all likelihood. Also, the robot arms which attatch to the top of the car will likely be the same shade of bley. The ends aren't final; I might replace the flat ends with dishes, but I'm not yet sure. Obviously, the undercarriage remains to be built in the coming months, and there are a few internal details that will be replaced. I wish I had a way of getting the bricks to all line up so that no gaps showed, but so it goes, I guess.
A paint scheme might be difficult to do on this model, as the main piece used doesn't come in a wide variety of colors - black, grey, white, red, orange, and yellow. Nonetheless, as this is primarily an industrial car, those should serve well enough for most purposes.
This picture is primarily to illustrate how I planned to accomplish the fairly-cylindrical body - the actual build has been adjusted quite a bit, due to weight and motor wear considerations. The surface consists of 8 curved 3x1 slopes, available on BrickLink here. Directly beneath the top two is a black 2x10 plate, which holds all the sections together. The blue pieces just below that are two jumper plates placed side-by-side, running lengthwise (this is done to achieve the same offset as the sides.) Below the blue jumpers is another long plate, though I believe this yellow plate is a 2x8. Every 8 studs, I would place another 2x6 red brick like the one shown here. Several things are attached to the red bricks: to hold the sides on, long technic bricks with several 1/2 pins support black 2x10 plates that correspond to the 2x10 supporting the top pieces. The two yellow headlights each have a 1x1 round dot piece on them which in turn supports the end cap sections. (The white plates underneath these are simply L-bends to provide additional support.) Two green 2x8 plates run lengthwise the full length of the car and underneath every red 2x6 brick, they provide the spacing needed for the two sideways 1x1 bricks with two knobs. These tan bricks provide the transition for the upside down bricks below, which follow the same pattern as the bricks of corresponding color above.