A typical river cargo and passenger steamer, as used in colonial areas of Earth and Mars. Her 625 HP twin cylinder steam engine can burn coal or wood (but in practice only sees wood); a simple condenser is fitted (mostly to avoid fouling the boilder with muddy river water). The stern paddlewheel has a protective wooden cover.

The hull is between 75' to 100' long, and 25' to 28' wide, with a draft of 3'. Loaded, the vessel weighs about 200 tons; it can carry about 50 tons of cargo and passengers. Crew consists of a captain, helmsman, 2 deckhands, cook/steward, engineer, 2 mechanics, and 2 stokers. Bench seats for a dozen or more persons are provided on the canopied upper deck; dozens more can sit or squat on the decks. Primitive cabins are provided for the crew, but none for the passengers (though many similar vessels might erect a deckhouse on the upper deck, with half a dozen cabins). If need be, up to about 250 persons could be packed aboard.

A cord (2 tons) of green (freshly-cut, soft) wood will supply the boiler for about 5 hours; top speed is about 10 knots. Steam can be raised from "cold" in about 3 hours.

No weapons are normally fitted, but military expeditions have successfully mounted minor weaponry on the decks of this type of vessel -- at most two machine guns on each side of the upper deck, and a cannon on the prow. Heavy wooden bulwarks, or sandbags, are usually fitted if the vessel expects to come under fire, providing a "midships" armor value of 1 (18 DEF in Hero terms).

Hull size 2, engine size 5 (50 tons), fuel bunker 10 (100 tons = 50 cords), mass number (4). Cost, about £10,000 on Earth; if constructed on Mars, with machinery and other iron parts imported from Earth, the cost is about £15,000.