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Dave steam 14 (trevithick)(42)

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  • 1. Steam Engines
    A series of lessons
    by David C
    Dec 2010
  • 2. Part 14
    Trevithick
  • 3. Okay, a lot of things are happening all at once,
    as we approach the end of the 1700s.
    2000
    First, there is the sprawling development
    of steam engines all over the UK.
    There are about 2000 steam engines
    in operation in the year 1800.
    1700
    1800
    1775
  • 4. A quarter of these are engines developed by Boulton, Watt & company, and use the condenser chamber designed by Mr Watt.
  • 5. A quarter of these are engines developed by Boulton, Watt & company, and use the condenser chamber designed by Mr Watt.
    The other three-quarters are Newcomen-style engines
    built either by Mr Watt’s current competitors or are the aging
    dinosaurs built 80 years ago by MrNewcomen himself.
  • 6. It seems as if a well-built steam pump
    or steam engine lasts forever.
  • 7. It seems as if a well-built steam pump
    or steam engine lasts forever.
    The old ones have been patched up and added to as the decades have rolled by.
    Given the massive cost of installing one in the first place,
    no-one is in a hurry to dig them up and throw them away,
    even if they are less fuel-efficient than the newer designs.
  • 8. The same thinking governs the use of water wheels and windmills.
  • 9. The same thinking governs the use of water wheels and windmills.
    Newcomen-style
    Watt
    Windmill
    Water
    80 years after the invention of the steam pump and 30 years after the invention of the rotary steam engine, four times as much power is coming out of the island’s water wheels and windmills as is coming out of all the nation’s steam engines.
  • 10. Some factories are using steam engines simply to lift water back to the top of a water wheel, or to force more water into the path of a water wheel.
  • 11. But the nature of industry is changing.
    Coal is a much more important commodity now than it ever was before.
  • 12. But the nature of industry is changing.
    Coal is a much more important commodity now than it ever was before.
    That means there are more numerous coalmines,
    more numerous canals and canal boats to carry coal,
    and more furnaces burning coal to make iron components
    for the machines that dig coal out of the ground.
  • 13. Some furnaces use steam engines to operate the bellows
    to blow air across the fire and raise its temperature
    to the point where iron will melt.
  • 14. Factories elsewhere are using steam engines to turn lathes
    that produce screws, bolts, nuts and washers
    (the basic ingredients of modern technology).
    All this means coal is now in high demand,
    more than before, when all it did was heat homes.
  • 15. So much coal is on the move now
    that there are traffic jams on the canals.
    Some communities want to install new railways,
    or extend existing ones so that they can bypass
    some of the congested river-ways.
  • 16. But those canal boats haul 30 tonnes of coal each,
    so railway wagons are going to have to be very big
    and very many in number to keep up with the supply
    that industry has grown used to.
  • 17. Heavy wagons will crush wooden rails, so the railways are being reinforced with strips of iron to make them stronger
    and the wheels of the wagons are being cast from iron as well.
  • 18. There is a move now to make steam engines smaller
    so that they can be erected at sites more easily,
    then disassembled and sold off to other people
    when they are no longer needed.
  • 19. Smaller engines fit better into textile mills,
    which make up more than half of Mr Watt’s customers.
  • 20. So you can see it coming, can’t you!
    Steam engines are getting smaller…
    Railways are being strengthened with iron…
    Coal is everywhere and everything on the move. …
  • 21. So you can see it coming, can’t you!
    Steam engines are getting smaller…
    Railways are being strengthened with iron…
    Coal is everywhere and everything on the move. …
    Everything is in place now for someone to invent a railway engine.
  • 22. The man who will do it is Richard Trevithick.
    He no longer lives next door to Mr Murdock
    but has returned to Cornwall where he is trying to set up
    his own steam engine factory, in direct opposition
    to Boulton, Watt and company.
  • 23. BW & co have had a stranglehold on the steam industry for 20 years
    and some of the miners in Cornwall have grown resentful of it.
    Richard Trevithick brings with him an air of defiance,
    and the miners are keen to see him do well.
  • 24. Trevithick’s business plan is actually very simple.
    He intends to use steam at very high pressure ,
    much higher than has ever been used before.
    That way, he doesn’t need to use Mr Watt’s condenser or any of the other gadgets that Watt has patented. He can make a piston go up simply by releasing steam into it, and can make it come down by letting steam escape from it.
    Simple, huh!
    There’s just one catch….
  • 25. Steam under higher pressure is very, very dangerous.
    If the rivets holding the boiler together should pop out under stress,
    then the thing will explode like a bomb
    and shower scalding steam over anyone standing nearby.
    … which is probably why no-one ever dared to go down this path before.
    James Watt is particularly opposed to any work in this direction and uses his influence to block it wherever he can.
  • 26. But a lot of progress has been made in metalworking in the last 20 years.
    Now it’s possible to bore a cylinder out of a single hunk of iron,
    in the same way that a cannon is made.
    The manufacturers say they can polish the inner surface
    “correct within the thickness of a shilling”.
  • 27. Trevithick’s first high-pressure engines are delivered in 1799.
    That’s good timing because a year later, Mr Watt’s patents expire
    and his 25-year monopoly over the steam industry is over.
    From that time one, Trevithick is free
    to add Mr Watt’s patented ‘gadgets’
    to his own design and come up with
    a powerful hybrid machine that is better
    than anything he or Mr Watt had before.
  • 28. The ‘Cornish engine’ as it was called sold well in Cornwall,
    where coal is expensive, but not so elsewhere.
    Industries throughout the UK had invested heavily in Mr Watt’s engines and were not prepared to spend another fortune
    on Trevithick’s design simply because it was a little bit better.
  • 29. A generation would have to go by and the machines would have to wear out
    before the new engines would be purchased in large numbers.
    This is not important to my story, however.
  • 30. What matters now is that Mr Trevithick has established a good reputation for himself and has made a little bit of money selling steam engines
    and has gained the friendship of several influential businessmen
    in his part of the country.
    He’s now in a position to explore an idea he’s had
    since he saw Mr Murdock’s toys, 10 to 15 years ago.
  • 31. Mr Trevithick wants to build a ‘steam carriage’.
    In 1801 he put a miniature steam engine onto the deck of a wagon
    and attached its piston to the back wheels.
    On Christmas Eve he took some of his friends out for a joy ride on it; the first time anyone in England had ever travelled overland on a vehicle not pulled by an animal.
    (The only other example I am aware of is Cugnot’s steam tractor)
  • 32. Three years later, Trevithick built a better version of it
    and drove it 150km across rough country roads
    to a port where it was loaded onto a ship and carried to London.
  • 33. Three years later, Trevithick built a better version of it
    and drove it 150km across rough country roads
    to a port where it was loaded onto a ship and carried to London.
    150km across rough country roads…
    What a journey that must have been!
    Imagine the farmers and their children
    leaning over the stonework at the front of their land,
    watching a fire-belching machine rumble by
    with a man sitting at the back of it.
  • 34. In London he hoped to inspire someone rich to invest in the engine,
    to pay for its development into a beautiful coach.
  • 35. In London he hoped to inspire someone rich to invest in the engine,
    to pay for its development into a beautiful coach.
    He had a suitably ornate drawing of one, just in case the entrepreneurs of London lacked imagination.
  • 36. I don’t know what happened during that visit.
    However, when Trevithick returned from London,
    he dismantled his steam carriage and used its parts
    to build stationary engines.
    He never built
    a steam carriage again.
  • 37. I don’t know what happened during that visit.
    However, when Trevithick returned from London,
    he dismantled his steam carriage and used its parts
    to build stationary engines.
    This all suggests that something bad happened in London.
    However, Trevithick may simply have replaced a good idea with a better one.
  • 38. Sometime during the year that he went to London with his steam carriage,
    he came across the work of a fellow named Matthew Murray,
    another engineer who had an interest in steam carriages.
  • 39. Sometime during the year that he went to London with his steam carriage,
    he came across the work of a fellow named Matthew Murray,
    another engineer who had an interest in steam carriages.
    Like Trevithick he had built a prototype and had tested it out thoroughly.
    The only difference
    was that he had driven it down a railway line.
  • 40. A steam carriage on a railway line?
    You mean one of those wooden pathways that the miners use to push coal wagons down the valleys to the canal boats?
    Does that strike you as a good idea?
  • 41. Mr Murray obviously thought so.
    A railway line is smooth and is so narrow that there is
    essentially no friction for a steam engine to fight against.
    The engine needn’t be so big, which means the vehicle can be lighter.
    And how many miles of railway line were there in Britain in 1804?
  • 42. End
    dtcoulson@gmail.com