The boiler shown in the illustration would be classed as __________. Illustration MO-0064

Correct Answer: Option B — single-pass, fire-tube, scotch marine

The Scotch marine boiler is a classic fire-tube design characterized by a large cylindrical shell containing internal furnaces and fire tubes. In a single-pass configuration, combustion gases travel from the furnace through the tubes to the uptake in one direction, typical of smaller or older auxiliary boiler installations.