NEW YORK, July 2, 2008 – ASME today will name the oscillating steam engine of the English manufacturer John Penn & Sons a historic mechanical engineering landmark. 

ASME landmarks are mechanical systems and devices that represent progress in the history of mechanical engineering.

The John Penn & Sons design, which was built in 1841 and is the oldest fully operational oscillating steam engine in the world, will be recognized in a special ceremony in Dresden, Germany.  Attendees at the ceremony will gather around the paddle steamer Diesbar, which was equipped with the award-winning engine in 1884.

The oscillating engine eliminated levers and other component parts common in previous steam engine designs, allowing a lighter and more compact power plant on the vessel.  Among its many design refinements, the John Penn & Sons engine features adjustable valves enabling the operator of the ship to set the desired cutoff for improved efficiency.

The ASME bronze plaque to be presented at the designation ceremony cites among the technical attributes of the engine its low center of gravity and direct mechanical linkages.

Writing around 1880, Robert Thurston, the first president of ASME, said the oscillating engine “is very compact, light, and moderately economical, and it excels in simplicity.”

The oscillating engine remained popular on steamers until the turn of the century, when improved boilers capable of higher pressure created opportunities for advancements in engine design and efficiency.

Since its inception in 1971, ASME has designated more than 230 historical mechanical engineering landmarks, heritage collections or heritage sites.

Founded in 1880 as the American Society of Mechanical Engineers, ASME is a not-for-profit professional organization promoting the art, science and practice of mechanical and multidisciplinary engineering and allied sciences.  ASME develops codes and standards that enhance public safety, and provides lifelong learning and technical exchange opportunities benefiting the global engineering and technology community.  ASME has more than 127,000 members worldwide.

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