Old Bess (beam engine)
Encyclopedia
Old Bess is an early beam engine
built by the partnership of Boulton and Watt
. The engine was constructed in 1777 and worked until 1848.
The engine is most obviously known simply for being an early example of an engine built by Boulton and Watt. However it also played a far more important role in the development of steam engine
s for being the first engine designed to work with an early cutoff
, and so to use the expansion of the steam for greater efficiency.
It is now preserved in the Power Gallery of the Science Museum, London. It is the oldest surviving Watt engine, and the third-oldest surviving beam engine.Two older Newcomen engines survive, one at Dartmouth
and one in the Henry Ford Museum.
's first engine at Kinneil had been unsuccessful and the parts were taken down and re-used at Boulton
's Soho Manufactory
in Birmingham
. The reworked engine was more successful here and encouraged Boulton to invest further in this developing steam technology, and Watt's inventions.
The Manufactory had been built to use a water wheel
to drive its machinery, and the site had been chosen on that basis, but there were concerns over seasonal lack of water to power the wheel. Similar problems in the iron industry had inspired the development of the water-returning engine
: a steam pump that could raise water to drive the wheel, in times of low water on the river. The Kinneil engine had been built as a pump, for use in a coal mine, and so was suitable for this new task. Watt's rotative beam engine had not yet been considered and so the only way to produce rotary work to drive machinery in the Manufactory was by water power.
In 1777 Boulton and Watt decided to build a second engine for use at Soho, either to supplement the Kinneil engine or primarily to experiment with Watt's new idea of expansive working of the steam. The new engine was also to be a water-returning engine Like the earlier Newcomen engines, it was only capable of pumping water rather than driving machinery directly.
. Early engines were incapable of this, as they used a single valve for both inlet and exhaust. As Watt had already begun to use separate valves for each function, it would now be possible to control their timing independently, i.e. to apply lead to the timing of the inlet valve. Watt decided to construct a new engine to demonstrate this principle and was confident of the substantial savings in coal consumption to be offered.Letter to Gilbert Meason, 24 April 1777, Boulton & Watt colln.
Construction began in 1777 with the ordering of a 33 inchEngines were characterised by and often named after the diameter of their cylinder. This dimension (amongst other factors) determined their power output, and whilst the working pressure and precise piston stroke length could be altered, the cylinder was fixed at manufacture. cylinder (84cm). The engine was erected and working at Soho by August, although still incomplete.
The engine always worked as a water pump and was equipped with two cast iron
cylinders at opposite ends of the beam, one for the working cylinder and one for the pump. The pump cylinder was taller and thinner, of 24 inches (61 cm) diameter and 8 in 3 in (2.51 m) tall, designed for a working stroke 7 feet (2.1 m) within this, although only 6 in 1 in (1.85 m) was used in practice. The pumped water was delivered at a head
of 24 feet (7.3 m). The engine was later described as being of 30 hp
in power.
The beam was typical for early single-acting beam engines, pulling through wrought iron
chains running over a curved arch-head at each end of the beam. At some later point, possibly when reconstructed after the fire, this beam was strengthened by being strutted and bridled with the additional timber and iron triangular trusses that are seen above the beam today.
.
Neither Watt nor Boulton had a solution to the engine's behaviour. Watt's experience with the Chacewater engine, a rebuilt Smeaton
engine, at Wheal Busy
, suggested that cutoff led to a violent action. In September he recommended throttling
the steam supply to the engine.Letter to Boulton, 20 September 1777, Boulton & Watt colln. Boulton favoured further experimentation with cutoff
(i.e. valve timing) and in 1779 suggested that a series of more scientific measurements be tried. With hindsight, Boulton's approach was the more thermodynamically efficient, although this lesson was not fully appreciated by locomotive drivers right to the end of steam power.
While the engine had been damaged, Watt, who was once again away in Cornwall, had advised that "no repair farther that the roof ought to be gone about at present", with his intention being to reconstruct the engine in some improved manner. The nature of these reconstructions, and their effectiveness, remains unclear.
By 1781, the engine had been working in its reconstructed form for some years. Whatever the improvements had been, they left Watt and Boulton still agreeing that this was, "one of the worst engines they had".Letter from Watt to Boulton, 1781, Boulton & Watt colln.
, until the mint's closure in 1848. It was sold for £48, then re-sold for £58 and placed on display on an island in Derrington Pool, outside the metal-rolling works of its new owner, a Mr. Walker. Although much of the Mint's coining
machinery had been re-sold for further use at the new Birmingham Mint
, this aged and thoroughly obsolete engine appears to have been one of the first artefacts of industrial archaeology
to be deliberately preserved.
The engine was later re-sold and then presented to the Commissioners of Patents for their Patent Office Museum, which would in turn become the Science Museum. The engine is thus not only one of the Museum's oldest exhibits, but also one of the first to enter its collection. When first displayed, the engine was erected in an open-fronted representation of a brick-built engine house. It is now displayed on free-standing timberwork, allowing a closer inspection of the cylinders.
For an engine that had been described as "one of the worst engines they had" when almost new, it had a relatively long working life of over 70 years. Its name had also shifted from the violent Beelzebub to the rather more friendly Old Bess, indicating a more satisfactory performance. Reports by both Joseph Harrison, Artificer of the Soho Mint and William Buckle support this.
The first of these confusions is that this was Watt's second engine (after the Kinneil engine) and the first by the Boulton and Watt partnership. In fact several engines were built between 1773 (the return of the Kinneil engine to Birmingham) and the construction of Beelzebub in 1777. These include such well-known engines as the 1775 38 inch blowing engine
for John Wilkinson
's blast furnace
s at New Willey, near Broseley
, and the 50 inch pumping engine for Bloomfield Colliery near Tipton
.
The identity of Beelzebub is also confused. Some sources describe this as referring to the rebuilt Kinneil engine at Birmingham. There are two pieces of evidence to support the view that Old Bess and Beelzebub are the same engine. Firstly the name Beelzebub derives from its violent action when used experimentally for expansive working, an experiment applied to the engine built new in 1777. Secondly Beelzebub is described as a 33 inch engine, as is Old Bess on display today. There is no record of Boulton & Watt ever building another engine of this dimension.
Beam engine
A beam engine is a type of steam engine where a pivoted overhead beam is used to apply the force from a vertical piston to a vertical connecting rod. This configuration, with the engine directly driving a pump, was first used by Thomas Newcomen around 1705 to remove water from mines in Cornwall...
built by the partnership of Boulton and Watt
Boulton and Watt
The firm of Boulton & Watt was initially a partnership between Matthew Boulton and James Watt.-The engine partnership:The partnership was formed in 1775 to exploit Watt's patent for a steam engine with a separate condenser. This made much more efficient use of its fuel than the older Newcomen engine...
. The engine was constructed in 1777 and worked until 1848.
The engine is most obviously known simply for being an early example of an engine built by Boulton and Watt. However it also played a far more important role in the development of steam engine
Steam engine
A steam engine is a heat engine that performs mechanical work using steam as its working fluid.Steam engines are external combustion engines, where the working fluid is separate from the combustion products. Non-combustion heat sources such as solar power, nuclear power or geothermal energy may be...
s for being the first engine designed to work with an early cutoff
Cutoff (steam engine)
In a steam engine, cutoff is the point in the piston stroke at which the inlet valve is closed. On a steam locomotive, the cutoff is controlled by the reverser....
, and so to use the expansion of the steam for greater efficiency.
It is now preserved in the Power Gallery of the Science Museum, London. It is the oldest surviving Watt engine, and the third-oldest surviving beam engine.Two older Newcomen engines survive, one at Dartmouth
Dartmouth, Devon
Dartmouth is a town and civil parish in the English county of Devon. It is a tourist destination set on the banks of the estuary of the River Dart, which is a long narrow tidal ria that runs inland as far as Totnes...
and one in the Henry Ford Museum.
Watt's previous Kinneil engine
WattJames Watt
James Watt, FRS, FRSE was a Scottish inventor and mechanical engineer whose improvements to the Newcomen steam engine were fundamental to the changes brought by the Industrial Revolution in both his native Great Britain and the rest of the world.While working as an instrument maker at the...
's first engine at Kinneil had been unsuccessful and the parts were taken down and re-used at Boulton
Matthew Boulton
Matthew Boulton, FRS was an English manufacturer and business partner of Scottish engineer James Watt. In the final quarter of the 18th century the partnership installed hundreds of Boulton & Watt steam engines, which were a great advance on the state of the art, making possible the...
's Soho Manufactory
Soho Manufactory
The Soho Manufactory was an early factory which pioneered mass production on the assembly line principle, in Soho, Smethwick, England, during the Industrial Revolution.-Beginnings:...
in Birmingham
Birmingham
Birmingham is a city and metropolitan borough in the West Midlands of England. It is the most populous British city outside the capital London, with a population of 1,036,900 , and lies at the heart of the West Midlands conurbation, the second most populous urban area in the United Kingdom with a...
. The reworked engine was more successful here and encouraged Boulton to invest further in this developing steam technology, and Watt's inventions.
The Manufactory had been built to use a water wheel
Water wheel
A water wheel is a machine for converting the energy of free-flowing or falling water into useful forms of power. A water wheel consists of a large wooden or metal wheel, with a number of blades or buckets arranged on the outside rim forming the driving surface...
to drive its machinery, and the site had been chosen on that basis, but there were concerns over seasonal lack of water to power the wheel. Similar problems in the iron industry had inspired the development of the water-returning engine
Water-returning engine
A water-returning engine was an early form of stationary steam engine, developed at the start of the Industrial Revolution in the middle of the 18th century. The first beam engines did not generate power by rotating a shaft but were developed as water pumps, mostly for draining mines...
: a steam pump that could raise water to drive the wheel, in times of low water on the river. The Kinneil engine had been built as a pump, for use in a coal mine, and so was suitable for this new task. Watt's rotative beam engine had not yet been considered and so the only way to produce rotary work to drive machinery in the Manufactory was by water power.
In 1777 Boulton and Watt decided to build a second engine for use at Soho, either to supplement the Kinneil engine or primarily to experiment with Watt's new idea of expansive working of the steam. The new engine was also to be a water-returning engine Like the earlier Newcomen engines, it was only capable of pumping water rather than driving machinery directly.
Construction
As early as 1769, Watt was considering the possibility of working steam expansively, as recorded in a letter of 28 May to Dr. SmallWilliam Small
William Small was born in Carmyllie, Angus, Scotland, the son of a Presbyterian minister, James Small and his wife Lillias Scott, and younger brother to Dr Robert Small. He attended Dundee Grammar School, and Marischal College, Aberdeen where he received an MA in 1755...
. Early engines were incapable of this, as they used a single valve for both inlet and exhaust. As Watt had already begun to use separate valves for each function, it would now be possible to control their timing independently, i.e. to apply lead to the timing of the inlet valve. Watt decided to construct a new engine to demonstrate this principle and was confident of the substantial savings in coal consumption to be offered.Letter to Gilbert Meason, 24 April 1777, Boulton & Watt colln.
Construction began in 1777 with the ordering of a 33 inchEngines were characterised by and often named after the diameter of their cylinder. This dimension (amongst other factors) determined their power output, and whilst the working pressure and precise piston stroke length could be altered, the cylinder was fixed at manufacture. cylinder (84cm). The engine was erected and working at Soho by August, although still incomplete.
The engine always worked as a water pump and was equipped with two cast iron
Cast iron
Cast iron is derived from pig iron, and while it usually refers to gray iron, it also identifies a large group of ferrous alloys which solidify with a eutectic. The color of a fractured surface can be used to identify an alloy. White cast iron is named after its white surface when fractured, due...
cylinders at opposite ends of the beam, one for the working cylinder and one for the pump. The pump cylinder was taller and thinner, of 24 inches (61 cm) diameter and 8 in 3 in (2.51 m) tall, designed for a working stroke 7 feet (2.1 m) within this, although only 6 in 1 in (1.85 m) was used in practice. The pumped water was delivered at a head
Hydrostatic head
When generating hydropower, the head is a general term used to describe the distance that a given water source has to fall before the point where power is generated. Ultimately the force responsible for hydropower is gravity, so a hydroelectricity plant with a tall/high head can produce more...
of 24 feet (7.3 m). The engine was later described as being of 30 hp
Horsepower
Horsepower is the name of several units of measurement of power. The most common definitions equal between 735.5 and 750 watts.Horsepower was originally defined to compare the output of steam engines with the power of draft horses in continuous operation. The unit was widely adopted to measure the...
in power.
The beam was typical for early single-acting beam engines, pulling through wrought iron
Wrought iron
thumb|The [[Eiffel tower]] is constructed from [[puddle iron]], a form of wrought ironWrought iron is an iron alloy with a very low carbon...
chains running over a curved arch-head at each end of the beam. At some later point, possibly when reconstructed after the fire, this beam was strengthened by being strutted and bridled with the additional timber and iron triangular trusses that are seen above the beam today.
Beelzebub
Initial operation of the engine was unsatisfactory. Watt was away in Cornwall and Boulton wrote to him, describing the engine's actions as "very fierce".Letter to Watt, 18 August 1777, Boulton & Watt colln. His opinion was that the engine's cylinder was too large for the work expected of it. This led to it being worked at a pressure of around 5.7 psi, whereas if it were operating at 8 psi, it would be less jerky and violent. This action was so remarkable as to give the engine its initial nickname of BeelzebubBeelzebub
Beelzebub -Religious meaning:Ba‘al Zəbûb is variously understood to mean "lord of flies", or "lord of the dwelling". Originally the name of a Philistine god, Beelzebub is also identified in the New Testament as Satan, the "prince of the demons". In Arabic the name is retained as Ba‘al dhubaab /...
.
Neither Watt nor Boulton had a solution to the engine's behaviour. Watt's experience with the Chacewater engine, a rebuilt Smeaton
John Smeaton
John Smeaton, FRS, was an English civil engineer responsible for the design of bridges, canals, harbours and lighthouses. He was also a capable mechanical engineer and an eminent physicist...
engine, at Wheal Busy
Wheal Busy
Wheal Busy, sometimes called Great Wheal Busy and in its early years known as Chacewater Mine, was a metalliferous mine half way between Redruth and Truro in the Gwennap mining area of Cornwall, England. During the 18th century the mine produced enormous amounts of copper ore and was very wealthy,...
, suggested that cutoff led to a violent action. In September he recommended throttling
Throttle
A throttle is the mechanism by which the flow of a fluid is managed by constriction or obstruction. An engine's power can be increased or decreased by the restriction of inlet gases , but usually decreased. The term throttle has come to refer, informally and incorrectly, to any mechanism by which...
the steam supply to the engine.Letter to Boulton, 20 September 1777, Boulton & Watt colln. Boulton favoured further experimentation with cutoff
Cutoff (steam engine)
In a steam engine, cutoff is the point in the piston stroke at which the inlet valve is closed. On a steam locomotive, the cutoff is controlled by the reverser....
(i.e. valve timing) and in 1779 suggested that a series of more scientific measurements be tried. With hindsight, Boulton's approach was the more thermodynamically efficient, although this lesson was not fully appreciated by locomotive drivers right to the end of steam power.
Fire and reconstruction
One morning in July 1778 the engine house was discovered to be on fire. The fire spread rapidly and within half an hour the roof was burned to the ground. The timberwork and soldered copper piping of the engine were also destroyed or damaged. Even the beam itself, a substantial timber construction, was "rendered unfit" by the fire. Fortunately the most important part of the engine, its cylinder, survived the fire relatively intact. Within three weeks the engine had been reconstructed and was expected to be working again shortly.While the engine had been damaged, Watt, who was once again away in Cornwall, had advised that "no repair farther that the roof ought to be gone about at present", with his intention being to reconstruct the engine in some improved manner. The nature of these reconstructions, and their effectiveness, remains unclear.
By 1781, the engine had been working in its reconstructed form for some years. Whatever the improvements had been, they left Watt and Boulton still agreeing that this was, "one of the worst engines they had".Letter from Watt to Boulton, 1781, Boulton & Watt colln.
Closure of the Mint and preservation
The engine operated at the Soho MintSoho Mint
Soho Mint was created by Matthew Boulton in 1788 in his Soho Manufactory in Handsworth, West Midlands, England. A mint was erected at the manufactory containing eight machines, driven by steam engine, each capable of striking 70 to 84 coins per minute....
, until the mint's closure in 1848. It was sold for £48, then re-sold for £58 and placed on display on an island in Derrington Pool, outside the metal-rolling works of its new owner, a Mr. Walker. Although much of the Mint's coining
Coining (mint)
In minting, coining is the process of manufacturing coins using a kind of stamping which is now generically known in metalworking as "coining".A coin die is one of the two metallic pieces that are used to strike one side of a coin...
machinery had been re-sold for further use at the new Birmingham Mint
Birmingham Mint
The Birmingham Mint, a coining mint, originally known as Heaton's Mint or Ralph Heaton & Sons, in Birmingham, England started producing tokens and coins in 1850 as a private enterprise, separate from, but in cooperation with the Royal Mint. Its factory was situated in Icknield Street , on the edge...
, this aged and thoroughly obsolete engine appears to have been one of the first artefacts of industrial archaeology
Industrial archaeology
Industrial archaeology, like other branches of archaeology, is the study of material culture from the past, but with a focus on industry. Strictly speaking, industrial archaeology includes sites from the earliest times to the most recent...
to be deliberately preserved.
The engine was later re-sold and then presented to the Commissioners of Patents for their Patent Office Museum, which would in turn become the Science Museum. The engine is thus not only one of the Museum's oldest exhibits, but also one of the first to enter its collection. When first displayed, the engine was erected in an open-fronted representation of a brick-built engine house. It is now displayed on free-standing timberwork, allowing a closer inspection of the cylinders.
For an engine that had been described as "one of the worst engines they had" when almost new, it had a relatively long working life of over 70 years. Its name had also shifted from the violent Beelzebub to the rather more friendly Old Bess, indicating a more satisfactory performance. Reports by both Joseph Harrison, Artificer of the Soho Mint and William Buckle support this.
Confusion between engines
Several confusions exist about this engine, and have been widely repeated.The first of these confusions is that this was Watt's second engine (after the Kinneil engine) and the first by the Boulton and Watt partnership. In fact several engines were built between 1773 (the return of the Kinneil engine to Birmingham) and the construction of Beelzebub in 1777. These include such well-known engines as the 1775 38 inch blowing engine
Blowing engine
A blowing engine is a large stationary steam engine directly coupled to air pumping cylinders. They deliver a very large quantity of air at a pressure lower than an air compressor, but greater than a centrifugal fan....
for John Wilkinson
John Wilkinson (industrialist)
John "Iron-Mad" Wilkinson was an English industrialist who pioneered the use and manufacture of cast iron and cast-iron goods in the Industrial Revolution.-Early life:...
's blast furnace
Blast furnace
A blast furnace is a type of metallurgical furnace used for smelting to produce industrial metals, generally iron.In a blast furnace, fuel and ore and flux are continuously supplied through the top of the furnace, while air is blown into the bottom of the chamber, so that the chemical reactions...
s at New Willey, near Broseley
Broseley
Broseley is a small town in Shropshire, England with a population of 4,912 . The River Severn flows to the north and east of the town. Broseley has a town council and is part of the area controlled by Shropshire Council. The first iron bridge in the world was built in 1779 to link Broseley with...
, and the 50 inch pumping engine for Bloomfield Colliery near Tipton
Tipton
Tipton is a town in the Sandwell borough of the West Midlands, England, with a population of around 47,000. Tipton is located about halfway between Birmingham and Wolverhampton. It is a part of the West Midlands conurbation and is a part of the Black Country....
.
The identity of Beelzebub is also confused. Some sources describe this as referring to the rebuilt Kinneil engine at Birmingham. There are two pieces of evidence to support the view that Old Bess and Beelzebub are the same engine. Firstly the name Beelzebub derives from its violent action when used experimentally for expansive working, an experiment applied to the engine built new in 1777. Secondly Beelzebub is described as a 33 inch engine, as is Old Bess on display today. There is no record of Boulton & Watt ever building another engine of this dimension.