Steam power was the driving force for much of the Industrial Revolution in the United Kingdom and United States. It brought travel around the world in eighty days within reach of commercial steamship and rail passengers by the late 1800s, while driving the expansion of both transport and industrialization in many parts of the world.

Understand
While pilgrimages and educational journeys such as the Grand Tour were established before the Age of Steam, it was steam vehicles which made travel a pleasure, and made recreational tourism possible, allowing common people to visit nearby cities and resorts, the middle class to cross the continent, and the wealthiest to travel around the world. The Grand Old Hotels usually trace their history to the Age of Steam.

Most reciprocating steam engines were supplanted by internal combustion engines or electric motors during the 20th century, especially in the decades following World War II. The number of steam trains dropped precipitously, due both to widespread dieselization or electrification of existing rail service and replacement of rail travel by highway travel. Steam turbines remain in common use for a few applications, such as electric power generation. Steam locomotives were held in reserve even in Western countries for a long time due to their ability to run on practically any fuel, but many of those have been sold to enthusiasts or scrapped in the 2000s and 2010s.

Steam engine

Early experiments
The first recorded rudimentary steam-powered “engine” was the aeolipile described by Hero of Alexandria, a mathematician and engineer in Roman Egypt in the first century AD. In the following centuries, the few steam-powered “engines” known were, like the aeolipile, essentially experimental devices used by inventors to demonstrate the properties of steam. A rudimentary steam turbine device was described by Taqi al-Din in Ottoman Egypt in 1551 and by Giovanni Branca in Italy in 1629. Jerónimo de Ayanz y Beaumont received patents in 1606 for 50 steam powered inventions, including a water pump for draining inundated mines. Denis Papin, a Huguenot refugee, did some useful work on the steam digester in 1679, and first used a piston to raise weights in 1690.

Pumping engines
The first commercial steam-powered device was a water pump, developed in 1698 by Thomas Savery. It used condensing steam to create a vacuum which raised water from below and then used steam pressure to raise it higher. Small engines were effective though larger models were problematic. They had a limited lift height and were prone to boiler explosions. Savery’s engine was used in mines, pumping stations and supplying water to water wheels that powered textile machinery. Savery engine was of low cost. Bento de Moura Portugal introduced an improvement of Savery’s construction “to render it capable of working itself”, as described by John Smeaton in the Philosophical Transactions published in 1751. It continued to be manufactured until the late 18th century. One engine was still known to be operating in 1820.

Piston steam engines
The first commercially-successful engine that could transmit continuous power to a machine, was the atmospheric engine, invented by Thomas Newcomen around 1712. It improved on Savery’s steam pump, using a piston as proposed by Papin. Newcomen’s engine was relatively inefficient, and mostly used for pumping water. It worked by creating a partial vacuum by condensing steam under a piston within a cylinder. It was employed for draining mine workings at depths hitherto impossible, and for providing reusable water for driving waterwheels at factories sited away from a suitable “head”. Water that passed over the wheel was pumped up into a storage reservoir above the wheel.

In 1720 Jacob Leupold described a two-cylinder high-pressure steam engine. The invention was published in his major work “Theatri Machinarum Hydraulicarum”. The engine used two heavy pistons to provide motion to a water pump. Each piston was raised by the steam pressure and returned to its original position by gravity. The two pistons shared a common four way rotary valve connected directly to a steam boiler.

The next major step occurred when James Watt developed (1763–1775) an improved version of Newcomen’s engine, with a separate condenser. Boulton and Watt’s early engines used half as much coal as John Smeaton’s improved version of Newcomen’s. Newcomen’s and Watt’s early engines were “atmospheric”. They were powered by air pressure pushing a piston into the partial vacuum generated by condensing steam, instead of the pressure of expanding steam. The engine cylinders had to be large because the only usable force acting on them was atmospheric pressure.

Watt developed his engine further, modifying it to provide a rotary motion suitable for driving machinery. This enabled factories to be sited away from rivers, and accelerated the pace of the Industrial Revolution.

High-pressure engines
The meaning of high pressure, together with an actual value above ambient, depends on the era in which the term was used. For early use of the term Van Reimsdijk refers to steam being at a sufficiently high pressure that it could be exhausted to atmosphere without reliance on a vacuum to enable it to perform useful work. Ewing 1894, p. 22 states that Watt’s condensing engines were known, at the time, as low pressure compared to high pressure, non-condensing engines of the same period.

Watt’s patent prevented others from making high pressure and compound engines. Shortly after Watt’s patent expired in 1800, Richard Trevithick and, separately, Oliver Evans in 1801 introduced engines using high-pressure steam; Trevithick obtained his high-pressure engine patent in 1802, and Evans had made several working models before then. These were much more powerful for a given cylinder size than previous engines and could be made small enough for transport applications. Thereafter, technological developments and improvements in manufacturing techniques (partly brought about by the adoption of the steam engine as a power source) resulted in the design of more efficient engines that could be smaller, faster, or more powerful, depending on the intended application.

The Cornish engine was developed by Trevithick and others in the 1810s. It was a compound cycle engine that used high-pressure steam expansively, then condensed the low-pressure steam, making it relatively efficient. The Cornish engine had irregular motion and torque though the cycle, limiting it mainly to pumping. Cornish engines were used in mines and for water supply until the late 19th century.

Horizontal stationary engine
Early builders of stationary steam engines considered that horizontal cylinders would be subject to excessive wear. Their engines were therefore arranged with the piston axis vertical. In time the horizontal arrangement became more popular, allowing compact, but powerful engines to be fitted in smaller spaces.

The acme of the horizontal engine was the Corliss steam engine, patented in 1849, which was a four-valve counter flow engine with separate steam admission and exhaust valves and automatic variable steam cutoff. When Corliss was given the Rumford Medal, the committee said that “no one invention since Watt’s time has so enhanced the efficiency of the steam engine”. In addition to using 30% less steam, it provided more uniform speed due to variable steam cut off, making it well suited to manufacturing, especially cotton spinning.

Road vehicles
The first experimental road going steam powered vehicles were built in the late 18th century, but it was not until after Richard Trevithick had developed the use of high-pressure steam, around 1800, that mobile steam engines became a practical proposition. The first half of the 19th century saw great progress in steam vehicle design, and by the 1850s it was becoming viable to produce them on a commercial basis. This progress was dampened by legislation which limited or prohibited the use of steam powered vehicles on roads. Improvements in vehicle technology continued from the 1860s to the 1920s. Steam road vehicles were used for many applications. In the 20th century, the rapid development of internal combustion engine technology led to the demise of the steam engine as a source of propulsion of vehicles on a commercial basis, with relatively few remaining in use beyond the Second World War. Many of these vehicles were acquired by enthusiasts for preservation, and numerous examples are still in existence. In the 1960s the air pollution problems in California gave rise to a brief period of interest in developing and studying steam powered vehicles as a possible means of reducing the pollution. Apart from interest by steam enthusiasts, the occasional replica vehicle, and experimental technology no steam vehicles are in production at present.

Marine engines
Near the end of the 19th century compound engines came into widespread use. Compound engines exhausted steam in to successively larger cylinders to accommodate the higher volumes at reduced pressures, giving improved efficiency. These stages were called expansions, with double- and triple-expansion engines being common, especially in shipping where efficiency was important to reduce the weight of coal carried. Steam engines remained the dominant source of power until the early 20th century, when advances in the design of the steam turbine, electric motors and internal combustion engines gradually resulted in the replacement of reciprocating (piston) steam engines, with shipping in the 20th-century relying upon the steam turbine.

Steam locomotives
As the development of steam engines progressed through the 18th century, various attempts were made to apply them to road and railway use. In 1784, William Murdoch, a Scottish inventor, built a prototype steam road locomotive. An early working model of a steam rail locomotive was designed and constructed by steamboat pioneer John Fitch in the United States probably during the 1780s or 1790s. His steam locomotive used interior bladed wheels guided by rails or tracks.

The first full-scale working railway steam locomotive was built by Richard Trevithick in the United Kingdom and, on 21 February 1804, the world’s first railway journey took place as Trevithick’s unnamed steam locomotive hauled a train along the tramway from the Pen-y-darren ironworks, near Merthyr Tydfil to Abercynon in south Wales. The design incorporated a number of important innovations that included using high-pressure steam which reduced the weight of the engine and increased its efficiency. Trevithick visited the Newcastle area later in 1804 and the colliery railways in north-east England became the leading centre for experimentation and development of steam locomotives.

Trevithick continued his own experiments using a trio of locomotives, concluding with the Catch Me Who Can in 1808. Only four years later, the successful twin-cylinder locomotive Salamanca by Matthew Murray was used by the edge railed rack and pinion Middleton Railway. In 1825 George Stephenson built the Locomotion for the Stockton and Darlington Railway. This was the first public steam railway in the world and then in 1829, he built The Rocket which was entered in and won the Rainhill Trials. The Liverpool and Manchester Railway opened in 1830 making exclusive use of steam power for both passenger and freight trains.

Steam locomotives continued to be manufactured until the late twentieth century in places such as China and the former East Germany (where the DR Class 52.80 was produced).

Steam turbines
The final major evolution of the steam engine design was the use of steam turbines starting in the late part of the 19th century. Steam turbines are generally more efficient than reciprocating piston type steam engines (for outputs above several hundred horsepower), have fewer moving parts, and provide rotary power directly instead of through a connecting rod system or similar means. Steam turbines virtually replaced reciprocating engines in electricity generating stations early in the 20th century, where their efficiency, higher speed appropriate to generator service, and smooth rotation were advantages. Today most electric power is provided by steam turbines. In the United States 90% of the electric power is produced in this way using a variety of heat sources. Steam turbines were extensively applied for propulsion of large ships throughout most of the 20th century.

Present development
Although the reciprocating steam engine is no longer in widespread commercial use, various companies are exploring or exploiting the potential of the engine as an alternative to internal combustion engines. The company Energiprojekt AB in Sweden has made progress in using modern materials for harnessing the power of steam. The efficiency of Energiprojekt’s steam engine reaches some 27–30% on high-pressure engines. It is a single-step, 5-cylinder engine (no compound) with superheated steam and consumes approx. 4 kg (8.8 lb) of steam per kWh.

Steam railways
While steam is seen with nostalgia or even longing for the “good old days” in places where the last steam service happened some decades past, many developing or emerging economies see the continued existence of any steam locomotives as “backwards” and an embarrassment. West Germany had a next-to-total ban of steam on mainline after the last official steam locomotives were withdrawn. Similar attitudes prevail today in some countries. That said, on marginal or otherwise abandoned lines, steam is still frequently to be seen and there is sometimes even a surcharge on tickets when steam locomotives operate compared to “regular” diesel trains.

Steamers, ships and boats
Before the widespread adoption of commercial air travel in the post-World War II era, mighty ocean liners plied the seas. The Royal Mail Ships of the RMS Titanic era, vying to transport the millionaires of the day, competed aggressively on both speed and luxury.

On inland rivers such as the Mississippi, the distinctive paddle wheel steamboat was once a common sight. A few still operate either as historic restorations or as replicas, imitations of varying accuracy.

Canada
RMS Segwun, Gravenhurst is a fully-operational restored steamship. Built in 1887, she originally transported vacationers to Muskoka cottages and delivered cargo and mail.
PS Trillium, Toronto, is a sidewheel paddle steamer which served as a Toronto Islands ferry from 1910-1957. She was restored and returned to service in the Toronto Island Ferry system in 1976.

England
A small number of small steam powered boats continue to operate on Windermere in the English Lake District.

Scotland
Steamship Sir Walter Scott, Trossachs Pier, Loch Katrine, By Callander, Stirling.
PS Waverley is the last sea-going paddle steamer in the world. Built in 1946, she sailed on the Firth of Clyde for many years. Since restoration, Waverley has operated regular excursions over the summer. Most are sailing from the Clyde, but there are also some trips up the west coast and Hebrides of Scotland, as well as around the Bristol Channel, Thames and south coast of England.

United States of America
Belle of Louisville, Louisville, Kentucky is the oldest operating Mississippi River-style steamboat and a National Historic Landmark.
Ticonderoga, Shelburne (Vermont) is a paddle steamer which served as a Lake Champlain ferry until 1969. Preserved and transported overland to the Shelburne Museum, she is now open for tours.

Static steam engines
The earliest use of steam power for industry was pumping (originally from mines), but large steam engines later become the motive power for all manner of industrial machinery, from textiles, to water supply. A few cities (including Otaru Japan, Vancouver Canada and Saint Helier Jersey) purport to operate a steam-powered clock – or a clock actuating a steam-powered whistle – as a local landmark in some central point in the village.

Canada
Pump House and Steam Museum, Kingston (Ontario), former steam-powered municipal water pumping station restored in the 1970s

England
Kew Bridge, Steam museum.
Bolton Steam Museum.
Forncett Industrial Steam Museum, Forncett St Mary, Norfolk, England NR16 1JJ, ☏ +44 1508 488277, ✉ [email protected].

Australia
Cockatoo Island in Sydney is home to a working steam crane that used to be used loading boats.
Steam carousels, gallopers and fairground equipment

Netherlands
Steam Carousel, Efteling.

England
Carter’s is a touring funfair, with some of the vintage equipment (notably its Gallopers) being steam operated. Operates seasonally, on a touring schedule, so venues vary.

Traction engines and steam cars

England
Hollycombe Steam Collection

Safety
Steam engines possess boilers and other components that are pressure vessels that contain a great deal of potential energy. Steam escapes and boiler explosions (typically BLEVEs) can and have in the past caused great loss of life. While variations in standards may exist in different countries, stringent legal, testing, training, care with manufacture, operation and certification is applied to ensure safety.

Failure modes may include:

over-pressurisation of the boiler
insufficient water in the boiler causing overheating and vessel failure
buildup of sediment and scale which cause local hot spots, especially in riverboats using dirty feed water
pressure vessel failure of the boiler due to inadequate construction or maintenance.
escape of steam from pipework/boiler causing scalding

Steam engines frequently possess two independent mechanisms for ensuring that the pressure in the boiler does not go too high; one may be adjusted by the user, the second is typically designed as an ultimate fail-safe. Such safety valves traditionally used a simple lever to restrain a plug valve in the top of a boiler. One end of the lever carried a weight or spring that restrained the valve against steam pressure. Early valves could be adjusted by engine drivers, leading to many accidents when a driver fastened the valve down to allow greater steam pressure and more power from the engine. The more recent type of safety valve uses an adjustable spring-loaded valve, which is locked such that operators may not tamper with its adjustment unless a seal illegally is broken. This arrangement is considerably safer.

Lead fusible plugs may be present in the crown of the boiler’s firebox. If the water level drops, such that the temperature of the firebox crown increases significantly, the lead melts and the steam escapes, warning the operators, who may then manually suppress the fire. Except in the smallest of boilers the steam escape has little effect on dampening the fire. The plugs are also too small in area to lower steam pressure significantly, depressurizing the boiler. If they were any larger, the volume of escaping steam would itself endanger the crew.