🔍 Key Concepts

• Bank suction and cushion effects when a vessel or tow operates close to a canal bank at speed • How water flow and pressure differ at the head of the tow versus near the towboat’s stern when close to a bank • Interaction between shallow water, narrow channels, and vessel maneuvering

💭 Think About

• Picture the water being squeezed between the right bank and the tow. Where will the water speed up, and where will the pressure be lower or higher? • Think separately about the front of the tow (the head) and the stern of the towboat: which part is closer to the bank and how will the water flowing past that side act on it? • Remember that suction tends to pull the hull toward low pressure, while cushion tends to push the hull away from high pressure near the bank.

✅ Before You Answer

• Identify which side (bank side or off‑bank side) experiences faster water flow and lower pressure when you are close to the right bank at high speed. • Decide whether the head of the tow will feel more suction (pulled toward) or cushion (pushed away) from the right bank. • Decide whether the stern of the towboat will tend to move toward or away from the right bank as a result of these interaction forces.