If none of the locomotives in your consist are equipped with alignment control couplers, what is the maximum number of locomotives allowed?

• A. 2
• B. 4
• C. 3
• D. 5

Answer: (C)

The key idea here is how alignment control couplers affect how many locomotives you can safely put in one consist. Alignment control couplers help automatically align the couplers between locomotives, which makes longer consists safer and easier to control. If none of the locomotives in the consist have this feature, the ability to keep all couplers properly aligned is reduced, so the safe limit is lower.

That’s why the maximum number of locomotives without any ACC-equipped units is three. With ACC on any unit, you could form longer consists safely, but with none of them equipped, three is the accepted limit.