The Powerhouse acknowledges the Traditional Custodians of the ancestral homelands upon which our museums are situated. We respect their Elders, past, present and future and recognise their continuous connection to Country.
18432 Steam engine, double-acting beam type, cast iron / wrought iron, made by Boulton and Watt, Birmingham, England, 1785, used at Whitbread's Brewery, London, England, 1785-1887. Click to enlarge.

Boulton and Watt rotative steam engine, 1785

This is the oldest rotative steam engine in the world. It embodies the four innovations that, together with extended patent protection, Matthew Boulton's capital and entrepreneurship, and James Watt's engineering skill and prudent management, made Boulton and Watt rotative engines the first commercially successful stationary power plants that were independent of wind, water and muscle.

Thomas Newcomen made the first successful steam engines in the early 1700s in England. Their output was …

Summary

Object No.

18432

Object Statement

Steam engine, double-acting beam type, cast iron / wrought iron, made by Boulton and Watt, Birmingham, England, 1785, used at Whitbread's Brewery, London, England, 1785-1887

Physical Description

The vertical cylinder is connected to a separate condensor (in a cooling tank with the air pump) to which spent steam is exhausted and cooled to form water, creating a partial vacuum. The piston, which is pushed up and then down by steam admitted to the cylinder below and then above it, is attached to the overhead beam via a set of 'parallel motion' linkages; this mechanism translates the vertical motion of the piston into the arc-wise motion of the end of the beam. The other end of the beam (which rocks up and down about a fixed pivot through its centre) transfers motion via a connecting rod to the 'planet' gear, which turns the horizontal drive shaft via the 'sun' gear; the names refer to the fact that the planet gear moves around the sun gear, which rotates but does not change position. A large flywheel, which maintains momentum between strokes, is attached to the horizontal drive shaft, which also carries the smaller toothed drive wheel and the governor pulley. The centrifugal governor controls the engine speed via a throttle (butterfly) valve in the steam supply pipe.

Cylinder bore is 635 mm (25 in), piston stroke is 1830 mm (6 ft), flywheel diameter is 4270 mm (14 ft), and the mass of the cast iron beam is 9.2 tonnes. Steam admission to the cylinder is via drop (poppet) valves, and a flap valve opens and closes the pipe between the condenser and the air pump.

Dimensions

Height

8400 mm

Width

10250 mm

Depth

5200 mm

Weight

33000 kg

Source

Credit Line

Gift of Messrs Whitbread & Co, Brewers, 1888

Acquisition Date

4 June 1888

Cite this Object

Harvard

Boulton and Watt rotative steam engine, 1785 2021, Museum of Applied Arts & Sciences, accessed 30 March 2023, <https://ma.as/7177>

Wikipedia

{{cite web |url=https://ma.as/7177 |title=Boulton and Watt rotative steam engine, 1785 |author=Museum of Applied Arts & Sciences |access-date=30 March 2023 |publisher=Museum of Applied Arts & Sciences, Australia}}