102. The boiler shown in the illustration would be classed as __________

The illustration depicts a horizontal scotch marine boiler with a single bank of fire tubes, classifying it as a single-pass, fire-tube, scotch marine design. This configuration features hot gases flowing through tubes surrounded by water, a characteristic of fire-tube boilers, and a horizontal cylindrical shell with an internal furnace, defining the scotch marine style. The single pass of gases through the tubes distinguishes it from two-pass designs, and its construction differs from water-tube and coil-type boilers.