This is the oldest operating vessel with a diagonal, compound steam engine, with disc valve gear. Operating at a higher pressure than the oscillating-cylinder engines then used in lake steamers, this type of engine was more powerful and efficient, as well as smaller. The compound engine, built by Sulzer brothers of Winterthur, uses super-heated steam from the boilers in two stages-high and low pressure-before exhausting it into a condenser. The engine produces 650 horsepower, turning two paddle wheels.