What was the Old Bess beam engine?

Old Bess was an early beam engine built by the partnership of Boulton and Watt in 1777 that remained in operation until 1848. It holds historical significance as the first engine designed to utilize an early cutoff, harnessing steam expansion for greater efficiency. Today, it is preserved in the Science Museum in London as the oldest surviving Watt engine.

What we know

• Old Bess was constructed in 1777 by the partnership of Boulton and Watt and operated until 1848. [2]
• It was the first steam engine designed to work with an early cutoff to use the expansion of steam for greater efficiency. [2]
• Old Bess is an instance of a beam engine as classified by Wikidata records. [1]
• It is recognized as the oldest surviving Watt engine and the third-oldest surviving beam engine. [2]

Where to go next

• whoWho were Boulton and Watt?
• whereWhere can you see Old Bess today?
• how it workedHow does steam cutoff improve efficiency?
• the bigger pictureWhat was the Watt steam engine?
• compared withWhat are the oldest surviving beam engines?
• an unexpected connectionHow did an 18th-century engine influence modern power generation?Old Bess pioneered early steam cutoff techniques, linking early industrial machinery directly to the thermodynamic efficiency principles used in modern power generation.

Sources

• [1]Old Bess (Wikidata Q7083463) · CC0 1.0
• [2]Old Bess (beam engine) · CC BY-SA 4.0
• [3]Bess · CC BY-SA 4.0
• [4]Cutoff (steam engine) · CC BY-SA 4.0
• [5]Watt steam engine · CC BY-SA 4.0