Historical Materials: Vessel Types

"Engine-powered vessel" is a collective term used by nautical historians to include all vessel types using engine power of any type for propulsion, whether assisted by sails, oars, or other motive power. In Lane's time, steam reciprocating engines fueled by wood or coal were the only practical source of this power for ships using paddle-wheels or screw propellers to convert heat energy into motion.

For most of the nineteenth century, steamships had sails for auxiliary power; indeed the earliest examples relied principally on sails, using engine power in calm weather to shorten the voyage time or keep to a schedule. As engines became more efficient, powerful, and reliable, sail plans were reduced, to be used only to steady a vessel's motion in a seaway (for the sake of seasick passengers), or to maintain headway if the engine broke down. Only harbor craft, ferry boats, and coastwise passenger steamers relied solely on engine power.

Among Lane's depictions of steamships, the auxiliary steam packet Auxiliary Steam Packet Ship Massachusetts (inv. 442) is a good example of primary reliance on sails, while the steam demi-bark The "Britannia" Entering Boston Harbor, 1848 (inv. 49) and the Cunard Liner "Britannia", 1842 (inv. 259) have relegated sails to secondary (or simply emergency) motive power.

– Erik Ronnberg