Compact grasshopper engines versus exposed crossheads

The grasshopper engine was a compact form of beam or half-lever machinery used in locomotives, riverboats, and tugs. That practical shallow-water role came with limited suitability for war or an Atlantic crossing. The crosshead engine took a different route, placing a tall square A-frame between a vessel's paddle wheels. Its exposed structure made the moving machinery easy to see but also looked fragile and vulnerable to damage. Together the examples show why engine layout had to match a ship's operating environment rather than simply deliver mechanical motion.