🔍 Key Concepts

• Lock dimensions vs. tow dimensions – compare overall length and width of each configuration to 600' x 110' • Typical standard barge size (about 195' x 35') and jumbo barge size (about 240' x 35') • What double lockage means – when the entire tow cannot pass in one cut because it’s too long or too wide

💭 Think About

• For each answer choice, sketch or visualize the tow layout (how many barges long and how many abreast, and where the towboat sits). Does the total width exceed 110'? Does the total length exceed 600'? • Pay attention to whether the towboat length should be added to the barge length in that configuration (e.g., is the towboat made up into the notch or alongside?). • Consider which situation would clearly force you to break the tow into two pieces (two cuts) in order to fit inside the lock chamber.

✅ Before You Answer

• For each choice, multiply number of barges abreast × 35 ft and compare to 110 ft lock width • For each choice, compute total length in feet (using ~195' for standard and ~240' for jumbo, plus the 150' towboat when appropriate) and compare to 600 ft lock length • Identify which configuration(s) cannot fit both length and width within the lock at the same time and therefore would require a double lockage