The horseless carriage piston down as well as up giving more power Watt also devised a way to turn the up and down piston motion into a round and round wheel motion Inventors show the way So if a steam engine could drive a factory machine why not a vehicle In 1769 Frenchman Nicholas Cugnot fitted a steam engine to a three-wheeled gun carriage It trundled along at 3 7 mph 6 km h but crashed and was soon forgotten It was Englishman Richard Trevithick who made the breakthrough He discovered that using steam at high pressure produced A Boiler over a fire B Cylinder where steam is condensed by cold-water spray DEF Rocking beam P Piston goes up and down C Cold-water tank V Valves Pump rod Steam power For thousands of years no human traveled faster than a horse could gallop After the invention of the first working steam engine in 1712 inventors started to dream of a horseless carriage a vehicle that could travel under its own steam The steam engine The ancient Greeks made steam toys for fun but the first person known to put steam power to work was British inventor Thomas Newcomen His 1712 atmospheric engine pumped water out of mineshafts and tunnels A fire under a boiler heated water to turn it to steam The steam entered a cylinder with a piston inside The piston was forced up and down to work the pump Similar pump mechanisms had existed for thousands of years but powering one by steam was new Other steam engines followed to power factory machines In the 1760s Scottish engineer James Watt built a steam engine with a sealed cylinder at both ends to make it double-acting the steam forced the This is Newcomen’s 1712 steam engine Steam from the water boiler was let in through a valve to the cylinder while the piston was at the top A spray of cold water cooled the steam which condensed lowering the air pressure inside the cylinder Higher air pressure outside pushed the piston down The piston drove a rocking beam linked to a pump The weight of the pump rod pulled the piston up for the cycle to begin again 8
This modern painting shows Richard Trevithick’s 1803 steam carriage A wooden carriage sat on two huge iron wheels with a small front wheel for steering The same tricycle design was used for Benz’s first automobile in 1885 Evans made it to dredge mud from the harbor and it even looked like a boat on wheels but the Digger needed no horses or sails It moved under steam power more power Watt thought this dangerous because the boiler could explode but Trevithick went ahead in 1801 with his first high-pressure steam carriage the Puffing Devil In 1803 he drove his second vehicle from Cornwall to London over 300 miles 500 km Given the terrible roads it was a miracle of engineering and persistence In the United States Oliver Evans had a similar idea In 1802 he showed his new Amphibious Digger in Philadelphia It frequently happens that two persons reasoning right on a mechanical subject think alike and invent the same thing without any communication with each other Oliver Evans Breakthrough The invention of the steam engine to power machinery spurred inventors to try to build steam-powered road vehicles In 1801 Richard Trevithick proved that a steam-powered carriage was possible 9
The golden age of steam Steam on the rails At about the same time as Trevithick and Evans unveiled their steam-driven vehicles railroad pioneers such as George Stephenson were building the first steam rail locomotives Steam on the rails progressed faster than steam on the roads By 1830 Britain had the world’s first steam railroad By the 1850s railroads were spreading across Europe and the United States Most people were thrilled by this new and fast way to travel To the surprise of some doctors train passengers did not collapse or die when speeding along faster than a horse Go slow on the roads It was a different story on the roads In Britain in the 1830s Walter Hancock started a steam bus service in London Gurney’s steam coach Sir Goldsworthy Gurney’s 1829 steam coach could carry 21 people and ran at 12 mph 19 km h It had six wheels the front two were for steering The metal boiler contained metal tubes filled with water A firebox burning wood or coal heated the water to steam and steam pressure drove two pistons in cylinders The piston motion was linked by rods and cranks to the back wheels of the coach This is Gurney’s steam coach on the road The drivers often found their way blocked by stones or trees put there by people eager to keep newfangled steam engines off the highways 10
High-pressure steam enters Valve rod directs steam to drive piston How steam engines work In a double-acting steam engine high-pressure steam drives a piston up and down inside a cylinder The cylinder motion is linked through a connecting rod and crank to turn the wheels The crank action moves rods to open valves which open and close to release used and fresh steam As steam enters the cylinder the piston is pushed one way then as more steam is let in through the inlet valve it pushes the piston back up inside the cylinder for the cycle to start again Piston is pushed forward by steam driving the connecting rod High-pressure steam and crank drive piston back Valve rod opens and closes valves Connecting rod Cylinder Crank and Sir Goldsworthy Gurney ran an intercity steam coach service but neither enterprise lasted long Problems with steam Steam trains were fast and efficient but they ran on timetables and they didn’t always take you where you wanted to go It was impossible to build railroads that linked to every street in every town and village but steam coaches and buses could go anywhere there was a road There were problems though Steam engines were big heavy and dirty They spat out steam and puffed out smoke and cinders They also needed a lot of water and coal to keep going and if the boiler ran dry it blew up The steamers scared horses and pedestrians so much that an 1865 law in Britain set a speed limit of 3 7 mph 6 km h and half that in towns for steam road engines Also a man with a red warning flag or a red lamp at night had to walk in front Interest in steam on the road fizzled out and while Britain led the world on rails its roads still belonged to the horse It was up to inventors and engineers in Europe and the United States to find alternatives to steam Breakthrough Steam engine technology progressed though road vehicles didn’t take off in the same way as trains Steam vehicles used a linkage system to transmit piston energy to the wheels This link technology endured while people searched for a better fuel 11
