What is an iron pig?

"Iron Pig" is a slang term for a railroad car, specifically a railroad hopper car used for transporting bulk materials like grain, coal, or sand.

Here's why it's called an "Iron Pig":

* Shape: Hopper cars are shaped like a large, rounded container, resembling a pig's belly.

* Material: Hopper cars are typically made of steel, hence the "iron" part of the name.

* Function: Hopper cars carry large amounts of material, similar to a pig's ability to consume and store large quantities of food.

So, next time you see a large, steel railroad car carrying bulk materials, you can confidently call it an "Iron Pig"!