The Romance of Steam

(How a steam engine works)

Due to the extensive mention of our debt to the steam engine, in all its forms, it has been suggested that an explanation and some history be provided.  Also, reasons why we no longer use this form of power. 

Let's address the question, "why do we no longer use this form of power".  The simple answer is that the Internal Combustion Engine" killed it.  Not that it is any better.  Perhaps in today's economic situation it actually is worse.  But, we have to look at the time frame and what happened. 

Steam engines have been with us for a very long time.  The very first engine was patented in 1698 by Thomas Savery.  It did not use any pressure containment so it was called an "Atmospheric Engine".  His design was improved by Thomas Newcomen in 1712, but it was still an atmospheric engine. It was not until 1769 when James Watt patented the first improvement to the atmospheric design.  He perfected a system that revolutionized the way steam was used that lead to first commercial application of steam as a real source of power. The principles he and others came up with resulted in the steam engine that most of us are familiar with (or have at least heard about).  Not only did James Watt build the first real steam engine but due to his contributions the measurement of power we all use is named in his honour.  The Watt, the measurement we all see in our daily life is his honour in posterity.

As a digression, I feel sorry for the generation of today missing the era of steam.  These folks familiar with the car and the diesel train have missed what is still today referred to as the "Romance of Steam".  There is not much to get excited about when we see a car or modern train engine.  But to those who have experienced steam engines there is nothing to compare.  A steam engine had a life of its own.  An individual character that still lives on in memories.  Memories of cold Prairie nights when the train came through.  A sound so distinctive you could tell what kind of train it was just by listening.  A sound in the night that could bring chills.  Literally huffing and puffing and talking it's own way through the night.

OK, back to the "why" question.  The answer was partly economics and partly our insatiable need to "Modernize" and use the latest technology.  Were it not for the cheap commodity called oil we might still be using steam.  Now with oil no longer being a cheap commodity perhaps we might find ourselves back in the Steam Age again.  In some countries, often referred to as "Third World", steam engines and steam trains survived for years past our conversion.  Sadly even those countries have had to convert to internal combustion.  Not due to economics but the simple fact that we have lost the ability to maintain and repair them.  They lasted forever when properly maintained.  But, as they used water and fire they needed constant maintenance. The "Boilermakers" of the steam age are gone.  Without the skills they had we can't keep steam engines running.  Except for a few "enthusiast" who thankfully are bucking the trend and restoring and running "Steamers" in all their forms.

Steam engines before they disappeared went through tremendous technological changes.  But the basic principal remained... take water, heat it to a boil and force it into a piston to make a wheel turn.  Pretty simple when you come down to it.  Toy steam engines are still around that take that simple principal and fascinate us all.  The result is always the same.  However the real operation was refined over years of use, research and experimentation. The environment itself dictated the evolution of steam power.  All aimed at making the most efficient use of fuels and water.  Where we had lots of wood we boiled the water with that.  Where we had lots of coal, that's what we used.  At the tail end of the era when oil became plentiful we converted to that fuel.  We ourselves had lots of the primary ingredient, water.  But in areas like South Africa where water was scarce even that was conserved.  In the majority of our uses the used steam was allowed to escape into the air.  That is what us fans of steam used to love to see.  Huge plumes of steam and smoke combined spewing out of the pistons and out of the stacks.  Not so in S. Africa, they condensed the steam and re used it.  Hardly a drop was wasted.

The steam engine and the internal combustion engine have a lot in common.  Force a piston to move, transfer that movement into power and harness it.  Internal combustion is just that.  Blow something up in a closed area and make the resulting gas expansion move a piston.  Steam is similar except that nothing blows up (hopefully).  Water when it boils expands into a vapour.  Take this vapour and put it into a cylinder with a piston in it.  The vapour pressure moves the piston which in turn is converted to the power, usually by being connected directly to a wheel of some sort.  Compared to an internal combustion engine a steam engine is a marvel of simplicity.  So simple in fact that it will run just as well in either direction.  Something that would never work in a car.  Image a car engine being able to do 60 or so miles an hour in either direction.  Some folk have a hard time controlling that fact going forward.  Not so with a train engine.  It runs just as well in either direction.  It never needed a transmission.  A steam engine could run directly from a dead stop to well over 60 MPH.  In the UK the steam engine Mallard recorded an official speed of 120 MPH.  A car needs a number of gears to achieve the same result.  But, we do have to remember a train needed a skilled engineer to make it work.  Something a car does not.  So, that is the trade off.  It was a simple design, but very complicated to run.

We have all heard about valves and engines.  But most folk could not care less.  The valves and the mechanism that runs them is concealed away and never seen.  Not so with the steam engine.  The mechanism that ran it was right there to be seen.  And was it a wonder to see!  Sometimes it has been suggested that for the mechanically inclined the mechanism had more attraction than the steam.   Gears, levers and valves are the stuff that steam engines are all about.

The machines were many, but there were 3 main uses.  Locomotives are the one we are most familiar with.  Traction engines (steam cars, trucks and tractors) are the sort of thing our grandparents remember.  The word "stream shovel" recalls the original large scale earth digging machines. Stationary engines however were just as important.  Loggers used them to lift and haul trees (Donkey Engines).  Miners used them for pumps and towing ore cars.  Just about every land based machine has had a background in steam.  I have never seen a steam powered airplane, but I am sure someone has tried it!  Electric power generation had a short period of steam piston power but that was short lived.  As an aside, power is still generated with steam.  But that is a modern application using the modern machine called a turbine.  Another story in itself,  briefly covered later.

Most steam enthusiasts today recall and follow the railway locomotive.  Depending on the use there were as many types of steam locomotives as there are cars and trucks on the road today.  Most were given names like Mikado, Pacific, Selkirk, Prairie and the like.   But, what we are most familiar with was what is classified as a "rod locomotive". This is the one we saw most often running through the towns where we lived.  Big wheels and driving rods down the side connecting to pistons near the front.  Speed and power was the mandate for these machines.  We built tracks so they could haul large trains at the highest speed possible.  However, if you were fortunate and lived near the woods you got to see some of the most interesting steam locomotives.  Small locomotives that carried their own water were often the norm. They were often called "Saddle Tanks" as the water tanks were built on top of the boiler and looked like a saddle on it.  Loggers did not have the luxury of being able to use the best terrain for tracks.  So locomotives with small wheels that could negotiate sharp corners on uneven tracks were the norm here.  As well, the rod locomotive had one problem.  It could not deliver enough power to the wheels.  So Geared Locomotives were the norm on these type of layouts.  Of these locomotives there were 3 distinct types. 

The Shay (named after it's inventor) had 3 vertical cylinders on the outside left side of the boiler.  That was connected to a crank which in turn drove shafts which drove the geared wheels. 

The Climax had two back and downward facing cylinders.  These were connected to a crank under the boiler which in turn drove a series of "bevel" gears which turned the wheels. 

The latter, the Heisler, was the first "V" shaped engine.  Two cylinders formed a V shape and drove a gearbox under the boiler.  Drive shafts then drove the wheels.  In all instances all the small wheels were powered.  100% of the available power was delivered to the rails.  And they could run on uneven rails with sharp curves. 

Often these engines ran on "narrow gauge".  The standard gauge (width between the rails) is 4' 8.5".  An exceedingly strange standard of measure.  But, it was inherited from the original builders of railroads, the British.  But, even they did not develop the standard.  Strangely enough we owe it all to the Romans.  They built the chariot just wide enough to cover the hind end of two war horses hitched side by side to pull them.  The ruts they left in the road were exactly 4' 8.5".  And being one of the main builders of roads in Europe and eventually Britain, when the rails were laid the British used the same rut dimension as the Roman Chariots.  When mining and logging railways were built a lot of them were built with lighter rails closer together.  There were two reasons they were done this way.  One reason is that sharp corners could be used. The other was a saving of wood for the ties which the rails were laid on.  Shorter ties (narrow gauge) meant the wood use was lower.  3 foot between the rails meant a saving of 1' 8.5" on every tie.  A considerable saving by the mile.

Where weight was important it was a curse for steam tractors.  The amount of weight that was required far exceeded the capability of most roads and fields.  So, the internal combustion engine was a savior for these devices. 

Donkey Engines as they were called benefited from the steam engine and lasted long into the 20th century.  The weight, the curse of the mobile tractors, was the boon of the Donkey.  A Donkey Engine is basically a winch.  One or more large drums winding in heavy steel cables hauled logs, pulled mine cars out of mines and powered the vertical elevators in the shafts.  The heavier the machine the more it could handle.  As well, it used available fuel.  In the woods they burned wood.  In the mines they burned coal.  And of course the common element of water was always accessible.

So, what of the future of steam power?  Well, honestly the use of steam to push a piston is long gone.  But, the ability of steam to turn a turbine has become the standard.  A turbine is nothing but a large fan powered by super heated steam.  It was tried briefly in locomotive engines, but proved too high maintenance.  But, in the generation of electricity it has reached its peak.  The use of clean burning fuels results in a total lack of pollution.  Something the alternative, diesel powered generators, cannot brag of.  With only one moving part, the turbine, the maintenance is almost none.  And  in some areas the waste product, steam, has other uses such as heating.  And thankfully due to the nostalgia associated with the steam fan and excursion trains are showing up everywhere.  The era may be gone, but the memory and experiences are timeless.

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