Dimensional loads or cars identified by the letter U may be placed anywhere in a train unless otherwise instructed.

• A. False
• B. True
• C. Only with RTC approval
• D. Only if the train is on mainline

Answer: (B)

Dimensional loads labeled with the U marker are treated with placement flexibility to help build trains efficiently. The rule is that these cars may be positioned anywhere in the consist unless someone in authority, such as the dispatcher or yardmaster, issues a specific instruction that limits their location. This means you don’t have a fixed slot for dimensional loads by default, but you must follow any overriding directives that may come for a given route, yard, or siding.

Think of it this way: the vehicle’s size or overhang requires attention to clearances and securement, but the general practice allows placement wherever it best fits the train’s makeup, weight distribution, and handling, as long as the appropriate safety checks are observed. If a particular movement has restrictions—perhaps due to bridge clearance, tunnel restrictions, or a temporary advisory—those restrictions would supersede the general rule.

So, the statement is true because, in normal operations, you can place dimensional loads anywhere in the train unless you’re given explicit instructions to change that placement.