Which Class B foam application method uses a bank to drop foam onto the spill?

Which Class B foam application method uses a bank to drop foam onto the spill?

• A. Roll-On
• B. Rain-Down
• C. Bank-Down
• D. Roll-Down

Answer: (C)

Bank-Down is the method that uses a foam bank to drop foam onto the spill. The foam solution is released from an elevated bank so it cascades down and blankets the hydrocarbon surface. This gravity-assisted drop covers large spills quickly, creating a thick foam layer that cools and blankets the fuel, helping to suppress vapors and reduce ignition risk. The other options involve applying foam by rolling or spraying in a rain-like pattern, rather than dropping from a bank, so they don’t achieve the same cascading, bank-to-spill coverage.

Bank-Down is the method that uses a foam bank to drop foam onto the spill. The foam solution is released from an elevated bank so it cascades down and blankets the hydrocarbon surface. This gravity-assisted drop covers large spills quickly, creating a thick foam layer that cools and blankets the fuel, helping to suppress vapors and reduce ignition risk. The other options involve applying foam by rolling or spraying in a rain-like pattern, rather than dropping from a bank, so they don’t achieve the same cascading, bank-to-spill coverage.