Uji was a metal-hulled gunboat with a triple expansion reciprocating steam engine with two boilers driving two screws.

The power plant was a double expansion reciprocating steam engine with four cylindrical boilers, driving two screws.

Maya was a metal-hulled two-masted gunboat with a horizontal double expansion reciprocating steam engine with two boilers driving two screws.

Three stage or triple expansion reciprocating steam engines, with three cylinders of increasing bore in line, were particularly popular for steamship propulsion.

Two vertical inverted triple expansion reciprocating steam engines powered by four double-ended Scotch boilers drove twin propellers, while two single-ended Scotch boilers supplied steam for auxiliary machinery.

Akagi was designed as a two-masted rigged schooner with a steam engine with a horizontal double expansion reciprocating steam engine with two cylindrical boilers driving two screws.

Atago was a iron-ribbed, iron-sheathed, two-masted gunboat with a horizontal double expansion reciprocating steam engine with two boilers driving two screws.