Steam engines for little explorer

Two-cylinder expansion compound steam engine of the excavator "Alberich" to drive the bucket chain, around 1927 (on the ground floor)

You are looking a 3 ton steam engine from the first half of the 20th century. Yes, that‘s right: not even 100 years ago, such machines looking ancient to us were used.

This steam engine was on the dredger "Alberich". The machine powered a chain to which buckets were attached. The buckets were used to dredge mud from the Moselle River in order to increase the river’s depth for shipping.

You can see that this machine has 2 cylinders at the top. The steam that moved the piston in the first cylinder has already lost pressure, but is still used again by being directed to the larger piston in the second cylinder. This makes the machine more economical and environmentally friendly. Sound economics and environmental sustainability are important goals today. In order for the machine to run smoothly, the steam, which had only a low pressure in the first cylinder after its work cycle, had to act on a larger piston area in the second cylinder. You can see the different sizes of the cylinders.

When the machine is working, you can also see how the pistons in the cylinders transmit their power via piston rods to a shaft below. Here the reciprocating movement of the pistons is converted into a rotary movement. Because the shaft is cranked via the protruding pins, the shaft is called the "crankshaft".

Next to the connecting rods you can see other, slightly thinner levers that move. This is the control of the valve slide for the live steam supply to the cylinders. A good and exact control was very important so that the machine could be operated economically.

At that time, a belt was placed on the flywheel on the crankshaft, which drove a smaller belt pulley, over whose shaft the bucket chain was moved.

With such a steam engine, the mud could be dredged much easier and faster than by hand.

This is a model that doesn't run on steam here in the museum. In order to be able to show how the parts move, the steam engine is moved by an electric motor. Instead of the steam engine doing work, the steam engine is driven here.

Just take a look at how everything works together on this machine.

For a steam engine you need hot steam. Hot steam you get when you bring water to a boil. To that end, in the past you needed an open fire fueled by wood or coal. It was a lot of work to fuel the machines. Once you could use oil as fuel for the fire, the work became easier, because you could pump the oil through pipes instead of hauling coal or wood. The hot steam then built up in large vessels under high temperature and high pressure. When steam engines were newly invented, boilers kept exploding. Think of an air balloon that is inflated too much and bursts. You just didn't know exactly how and what to build the boilers from so that they could withstand the pressure. The steel from which boilers were built of was not as good as today's steel. Furthermore, the boilers were hand made. Sometimes people made minor or major mistakes when building them. Also, during boiler operation, operator errors occurred which caused the boiler to burst. It took time to learn from these mistakes. With the number of steam engines increasing and with the steam engines operating under ever higher steam pressure, the number of accidents also increased. Around 1860 governments issued building specifications. Operation rules were introduced to safely operate the machines. The steam boilers, for example, had to be housed in in special buildings apart from the rest of the factory. If something went wrong, it went wrong only there.

When water boils in a cooking pot, the lid often starts rattling. That is the force that also works in the steam engine. In steam engines, the force of the steam is directed onto a piston, which then moves back and forth. This reciprocating movement of the piston is then converted into a rotary movement via a lever. In the beginning, steam engines were very slow because the steam worked the piston in only one direction - the outward movement. It's like a bicycle pump. It only pushes in one direction. The machines became much faster once you could let the steam act alternately against the piston from both sides via a valve. The more steam you could supply, the faster the steam engine worked. In many steps of development, the engineers succeeded in making the steam engines run faster. But the speed of such a fast machine had to be be controlled. We heard that when water boils in a cooking pot, the lid often starts rattling. Imagine that you had to set the rattle, let's say one rattle per second, using only the stoves heat controls. You can only do that with luck, but steam engines must work precisely. The amount of steam affects how fast the steam engine runs. Too much steam can cause the machine to explode. That happened quite often in the past. Lots of ideas had to be tried first. The centrifugal governor was an important invention. With it, the amount of steam supplied could be set in a stable manner. Suddenly it became possible to drive looms, mills, ships and railway wheels with steam engines.

Very early on, people observed that steam can exert a force. Heron of Alexandria demonstrated this vividly with his Aeolipile, which we had replicated to show you.

In this film we operated the aeolipile with steam for you to see how it works. The steam generated by heat/fire is introduced into the ball and builds up more and more pressure. The pressure can escape through the two curved tubes on the outside of the ball. As the ball can rotate, the steam pushes away the ambient air, it forces it away. Now, in physics, force equals counterforce. Here, the counterforce is a recoil that makes the ball spin.

With this arrangement Heron of Alexandria showed that something can be moved with steam. Much later, this knowledge was implemented for steam engines.

By the way, this model was built by apprentice locksmiths in the IHK apprenticeship workshop in Neuwied, the IHK being the “Chamber of Industry and Commerce”. Look what a great thing the locksmith trade is!

The Greek scholar Archimedes considered as early as 250 BC to build a cannon that could drive projectiles with steam. About a hundred years later, Heron of Alexandria thought about how to use steam pressure to set a device in a rotary motion. Neither of them however built a useful machine following their ideas. Inventors only succeeded in doing this hundreds of years later. Thomas Savery built a steam-powered pump in England that pumped water from mines. It was the first steam engine that did work which formerly people had to do. But it was still very laborious to use. Because of this, the efficiency of the machine was low. The English wanted to dig for mineral resources in deeper layers of the earth. The English blacksmith Thomas Newcoman knew that mines always needed better pumps That is why he improved the steam pump and increased its efficiency from 1712 onwards. Around 40 years later, the Scot James Watt improved the steam engine yet again by stepping up its controllability. With his ideas, the machine’ pistons could push or pull and turn more evenly. Wherever power was needed before, be it by water, wind or muscle, people could now use steam engines.

Three-cylinder triple expansion steam engine "De Klops, Sliedrecht (NL)" for driving paddle steamers, 1898 (on the 1st floor)

Here see a standing steam engine weighing 7 metric tons, which operated, at the time, under high steam pressure. By the way, 7 tons is as much weight as 7 small cars.

This steam engine was built in the Netherlands shortly before 1900. The Dutch were a seafaring people.

This 300 hp machine has three cylinders of different sizes at the top, into which the steam is introduced one after the other, just as with the steam engine on the ground floor. Each cylinder had its own control. This is the slightly thinner rod next to the individual piston rods. You can also see an enclosed centrifugal governor on top of the machine.

The force was transmitted to the crankshaft below via the piston rods. Operating under the principle of using the steam several times, it was possible to build powerful and economical steam engines. By the way, what matters in these slow-running machines is less the power in horsepower than the torque. And that was extremely strong with these steam engines.

The crankshaft has two ends that have been sawn off to fit the machine in here. On the side facing the door you can see a disc offset from the center of the axis. Ancillary units such as a water pump could be driven with this disk.

This steam engine drove the paddle wheels of a paddle wheel steamer. By the way, with the big red wheel the direction of the steam engine could be reversed. The machine operator received information on machine operation from the ship’s master.

Ships powered by a high pressure steam engine could travel twice as fast as ships with a low pressure steam engine. This cut travel times in half. That was a strong argument in favor of transporting people and cargo.

In order to be able to build a powerful machine like this one, you needed good steel. Steel was only developed with the demands that steam engines brought about with their own advent.

Until the beginning of the 18th century, the predominant material for mechanical engineering was wood. That was just 300 years ago, when steel was just being invented. It was still very expensive and could only be worked upon with great effort. Many components of early steam engines were still made of wood. But the boilers and pipes had to withstand a lot of heat and moisture. Pistons had to move in the cylinders. Wood was not suitable for this. Therefore, many parts had to be made of steel. Because of the great forces in the steam engines, the steel had to be stable. It had to withstand tension and pressure and was not allowed to tear even with the many temperature changes. If possible, it shouldn't rust either. Since the first steam engines, many „recipes“ for the composition of steel and manufacturing processes have been tried Steel has been continuously improved. Steel became stronger and more elastic at the same time. A hundred years ago, steel parts had to be about six times as large as they are today to withstand the same forces. As with a pizza dough, steel parts have slightly different properties with different ingredients. When talking about steel, this mixing is called “alloying”. Hence, a „recipe“ for steel is called an “alloy”.

This is a model of a “locomobile”, a locomotive that can run on the road. Something like this actually existed in the late 19th century, before combustion engines were invented.

In contrast to industrial steam engines, all the components required for the drive are mounted on a mobile platform in locomotives: the furnace, a horizontal boiler, a chimney and the steam engine itself.

This locomobile was built by R. Wolf in Magdeburg.

This model was built and made available to us in 2001 by the model maker Probst. The model really works and can drive!

Locomotives were powered by steam engines. You can see that on this model.

But what you can also see well is a centrifugal governor. This is this delicate carousel with the two iron balls on top of the boiler of the steam engine. With this centrifugal governor, the speed of the steam engine could be kept constant.

In order for steam engines to run smoothly and not break down, their output had to be regulated.

James Watt used the centrifugal governor that was already known at the time.

You can imagine it like a chain carousel at a fair. The faster the carousel turns, the more you will be pressed outward in your armchairs. The force that works here is the centrifugal force.

Exactly this principle is used in the centrifugal governor. If the steam engine's flywheel rotates faster, weights in the regulator are pulled up and out via a lever mechanism. This is how the speed can be measured. Using a linkage from the regulator, the supply of live steam to the steam engine can also be regulated at the same time. A slide is continuously moving depending on the measured speed. In this way the speed at which the steam engine runs can be kept constant.

To this day, controllers are important components in mechanical engineering. However, most of the control processes are now electronic.

Here you can see the complete drive train of a ship. You can already see that it is a ship that was powered by a steam engine and that transmits the power to the water via a propeller converting the power to propulsion. This means the ship is pushed ahead by the propeller.

If you hold down the button on the front of the showcase for 2 seconds, the drive begins to move. You can easily see how the movement of the steam engine is transferred to the propeller at the stern of the ship.

On the left you can see a standing single cylinder steam engine from the English steam engine manufacturer Stuart. You see the black cylinder. The steam control is also easy to see. The shaft sits directly on the crankshaft lying lengthways in the ship and is supported in multiple ways up to the four-blade screw.

This illustrative model was built by Mr. Witt from Vallendar, who made it available to the museum. Mr. Witt is a model maker. That's a nice job too, don't you think?

But also in reality such drives had to be designed, built and tested. These are tasks for engineers to this day.

A lot of knowledge was required to build and operate steam engines. You had to understand something about pressures and temperatures; But you also had to understand something about construction. Finally, one had to know suitable materials with which one could build what was constructed.

The first mechanical engineers were inventors who wanted to do something new with just a few basics. They tried a lot and learned from what worked and what didn't. Especially, they learned from mistakes they made. These mechanical engineering pioneers often spent their entire lives to somehow realize their idea. Often they used everything they had. Some of them lost everything. But some managed to turn their ideas into reality. Few also knew how to market their inventions well and became wealthy.

Such “machine inventors” are still needed today. What they do has now become a profession that can be learned and studied.

With the spread of the steam engine, the knowledge gained was systematically recorded and further developed. Tinkerers have become scientists. Engineering developed.

The engineering profession is very exciting because you can develop good ideas and implement them with technology. The professional field today goes far beyond pure mechanical engineering. Engineers deal with environmental technology, chemical contexts, electrical engineering, Internet applications and many other things.

Steam indicator for measuring the horsepower of a steam engine (in a showcase on the 1st floor)

Now you are standing in front of a Case with all kinds of parts in it. What could that be? How does this case relate to steam engines?

Well, this case contains components of a measuring instrument. With this instrument, the steam pressure in the cylinders of steam engines could be measured. What was that good for? The power of the steam engine could be calculated from the pressure. Watch the movie to learn more.

(illustrative film in which the steam indicator is assembled and attached to a cylinder of a steam engine)

In the 18th century, many manufacturers wanted to sell their new steam engines.

Steam engines were relatively new to the market. Customers could choose between different Select makes and models. They saw big machines made of steel and could get themselves don't imagine what achievement they received.

For almost 100 years, customers of steam engine manufacturers had to believe what the sellers told them. There was no useful measuring device for reliably measuring the performance of a steam engine, although many tried to develop one.

The contents of this little box in the showcase is a steam indicator that solved this problem by the end of the 19th century.

If connected to the cylinder of a steam engine, it measures the steam pressure in the cylinder in every piston position and uses a mechanism to draw the measurements as a curve on paper. Experts then could tell how well the machine was working from the shape and size of this curve.

Since there have been reliable steam indicators, steam engine salespeople can no longer fool their customers. Steam indicators have also been used to improve operations in steam engines.

Paddle wheel based on the model "2 horizontal steam engines" and possibly based on a model that we can obtain (on the 1st floor)

This model shows that sometimes 2 steam engines were installed on ships. In this case it is horizontal steam engines. You can see that the pistons do not work from top to bottom, but horizontaly, “lying down”, so to speak. This is what you did back then when the steam engines were supposed to drive paddle wheels.

Here you see that every steam engine should drive its own paddle wheel. The paddle wheels were attached to the stern of the ship, i.e. at the rear. They pushed the water backwards, moving the ship forward.

Both steam engines acted on the same paddle wheel. Do you see the the levers of the steam engine acting on the paddle wheel at a right angle to each other?. This trick made it possible to start the paddle wheel from any position.

Such a a paddle wheel was built into the model in the showcase: the "Tennessy-New Orleans".

She was steered with two oars in front of the paddle wheel at the stern. But these ships did not steer really well, as you can certainly imagine. On the other hand, they were not as wide as ships that had their paddle wheels on the side of the hull.

Such drives were well suited for shallow waters with low currents. However, such types of propulsion are completely unsuitable for operation on rivers with a strong currents like the Rhine River.

If you look at the paddle wheel shown, you can also see that the paddles are firmly attached. That's why they just splash into the water. Ships with such simple paddlewheels could not make good progress.

Engineers had recognized that stationary blades made more foam and spry than propel a ship forward. So shipbuilders looked for better solutions. The blades should plunge vertically into the water with each rotation of the paddle wheel and remain vertical under water while pressing the water backwards until they emerged.How did they do that? Do you have any ideas?

You are standing in front of a great model that the IHK trainees built for us in the Neuwied training workshop. (The IHK stands for the “Chamber of Industry and Commerce”.)

This model clearly shows the solution the shipbuilders had found: They attached the blades to the drum so they could pivot. They used levers to control the position of the blades depending on the position of the blades in relation to the water. To achieve this, the levers are attached to a ring that is offset to the axis of rotation of the paddle wheel. This arrangement is called an 'eccentric attachment'. This Model depicts that clever lever mechanism, which worked very reliably.

With these eccentrically controlled blade positions, the water could actually simply be pushed backwards. The ships got faster and didn't need as much energy. The costs for operating the ships sank. Furthermore, our environment benefited from the adjustable shovels. But at the time, that was probably not an issue.

How can you transfer propulsion power to the water? When swimming, we do this with our hands and feet. The principle is transferred to the paddle blades when paddling. So the ancient Romans considered building ships with paddle wheels. Around the year 400 there was a ship in China with a paddle wheel that was turned with muscle power. It was only much later that muscle power was replaced by power from steam engines. The paddle wheel stayed. The Frenchman D’Abbas built the first paddle wheel ship with a steam engine in 1782. The paddles pushed the water away by turning. Much like your hands when swimming, they set the ship in motion. Some ships even got a steam engine and a paddle wheel on each side. This allowed you to steer each side individually and steer long ships better. If you just splash in the water while swimming, you can barely move forward. You know that. Moving forward depends on the technique. The blades of simple paddle wheels just splashed into the water, so that much energy was lost. The engineers then came up with a mechanism with which they could dip the blades vertically into the water. That way the shovels were far more efficient. The power that had to be laboriously gained through the coal, fire, steam and piston movement could now be used better. The powerful steam engines were well suited to propel ships. But still a lot of power was lost through the paddle wheels. So the engineers thought again and invented the ship propeller. Much research has been done on this. Wi know that there is a particularly good propeller shape and size for every application. Modern ship propellers can even be adjusted while driving so that they always work optimally.

Deflection of the oscillating movement into rotary movement based on the steam engine model (in the stairwell, 1st floor)

Here in the stairwell is a particularly beautiful model of an industrial steam engine. The model can even be set into motion with compressed air.

It is an early form of what is known as a balancer steam engine. You can tell why this type of machine is so called by the large rocker above the machine, the so-called balancer. In this type of machine, the crankshaft is not located under the cylinder. Rather, the piston movement is transmitted via the balancer. You can see the crank drive under the second end of the balancer.

The flywheel is particularly large on this machine. It has to compensate for the uneven running of the single cylinder.

Due to their design, such machines ran very slowly.

The model of this steam engine is built in the same way as steam engines which were used in mines. They drove pumps to pump the groundwater out of the tunnels.

Mr. Witt from Vallendar, who built this model very carefully, made it available to the museum.

You can see particularly well how the back and forth movement of the piston rod is transformed into a rotary movement of the large flywheel. A simple lever construction with a joint is used for this. The second lever can pivot. One end is attached to the joint on the piston rod. Its other end is attached to the flywheel outside the axis of rotation. When the piston rod moves back and forth, the flywheel can be set in rotation using this simple lever mechanism.

By the way: do you know why the flywheel is so big? The flywheel has a large mass. Great masses have great indolence. You know that when you want to brake your bike. The bicycle that is in motion does not stop immediately, because first of all, all of the inertial mass that you and your bicycle have must be braked. The brakes must first „destroy“ the kinetic energy of your bike for you to come to a stop. – Wait a minute- destroy energy? No, energy cannot be destroyed at all. It is converted into another form of energy. On your bike, the energy of movement converts into thermal energy that is absorbed by the rims of your bike. The rims get warm when braking. Just feel it the next time you ride your bike! This knowledge about the impossibility to destroy energy is used with the flywheel. Once the energy that has gone into setting the flywheel in motion, the energy is kind of stored there. Once the flywheel is spinning, its mass helps keep it rotating evenly. So the steam engine can be better used as a work machine.

Speaking of 'work machine': Various machine tools can be connected to such a steam engine via belt drives. So factories could be operated in the 19th century. A generator could also be connected to produce electricity. Incidentally, modern steam turbines are still used in power plants today, which generate electricity via generators. So the principle of the steam engine lives on - in highly efficient processes!

Steam engines were used, among other things, to propel tugboats.

Here we have a model of a typical tugboat powered by a steam engine.

If the model is approximately 77 cm long and was built on a 1: 100 scale, how long was the original ship? It was 77 m long. Of course you found that out too. That was a typical size for such tugboats.

Around the year 1830, such tugboats replaced the so called “Tauerschiffe” (literally towing ships) which still had to pull (or tow) themselves laboriously upstream using rope sheaves on thick wire ropes laid in the Rhine River. But that technique was very cumbersome and didn't catch on, when the tugboats appeared.

With up to 2000 hp steam engines and paddle wheels, cargo ships could now sail independently on the Rhine River - without a rope. They were independent and much stronger too. Such tugboats could pull up to 8 barges.

It was not until 1880 that the paddle wheels were gradually exchanged for ship propellers. The ships with screws were not so powerful and needed deeper water because the screws are attached under the hull of the ships. Such tugboats operated on the Rhine River until 1973.

The tugboats were equipped with winches and rope clamps. The wire ropes were clamped on deck with the rope clamps, which you can see on the model. The entire tensile force lay on these clamps. In addition, the ropes did not rub against the deck. To protect the crew, bows were stretched over the deck over which the wire ropes ran.

The two boilers show that at least one steam engines was installed. Unfortunately, you cannot see whether it was one or two steam engines which were installed.

Manufacturers of steam engines wanted to sell their machines at good prices. Buyers had to be able to imagine how much work the steam engine could save them. Back then, horses did a lot of hard work for people. This is why the power of steam engines was compared with that of horses. James Watt suggested that the power required to raise 75kg by 1 meter in 1 second be called “one horsepower”. The unit "horsepower" has since been used to describe the performance of a mechanical machine. Now you could compare all machines and imagine something under the specified machine output. In order to also be able to measure and compare also electrical output or heat output, it was later agreed to specify output in "kilowatts". The name comes from James Watt. Horsepower can also be converted into the unit “kilowatt”. One kilowatt is about ¾ of a horse power. Today, the performance of all machines - from cars, kitchen appliances to jets - is given in kilowatts.

On this tour, you have already seen a model of a tugboat. In this showcase you can find out about how these tugboats were used. In the past, such tugboats sailed on the Rhine River and pulled up to 8 barges. Such a team could be up to a kilometer long. You can see what it looked like here in the showcase.

Think about how much the wire ropes must have weighed when they were 4 cm thick and up to 1 km long!

On the left in the showcase you can see the tugboat 'Peter Küppers', which apparently operated two firings and two steam boilers. You can tell from the two chimneys. The steam engines drove two side paddle wheels. Unfortunately, the rope clamps are not shown on this model. But you can clearly see that the tugboat has all the ropes aboard to pull the barges.

To do this, the tug came close to the boat to be towed, which was at anchor, and the tug’s crew passed a towing wire to the barges crew to be attached to the barges using so-called 'Brittelhaken'. The barges then dropped back behind the tugboat until finally they were being towed behind once the towing wire was taut. If other barges wanted to join, they were also picked up by the tugboat and integrated into the existing association. The tow trains could reach lengths of one kilometer.

Upstream, the barges were towed one after the other (in keel line) up the Rhine River. That way, they had less water resistance. Downstream, barges were towed side by side. Not only the tugboat but also every boat had to be steered with an rudder. Several men had to hang on to at the large steering wheels, which were up to 6 m in diameter. You can imagine how exhausting it was. For this reason, steam-powered rudder machines were later installed, which acted like power steering.

If a barge wanted to detach itself from the network, the crew released their towing wire from the ship and let themselves drift into the harbor. There they were pulled ashore with locomotives or winches. The crew had slow down the barge by hand. It was dangerous work that required a lot of experience.

Until 1967 one could see tow formations on the Rhine River. Ever since, all ships have been sailing on their own.

The invention of the steam engine, which was used to drive ships in the 19th century, was a great relief for the people. People and goods could now be transported on the Rhine River independently of muscle power, wind and cables. The time required for travel and transportation was greatly reduced. Everything started to get faster.

On this painting by Princess Charlotte von Preußen you can see what the steam engines did to our air.

The smoke from the chimneys darkened the sky. You could hardly see the sun any more. That was well into the 1960s the case in the Ruhr area, where there was a lot of industry,. You can't even imagine that today.

Unfortunately, it wasn't until much later that people realized that not only could they hardly see the sun, but that the exhaust gases were also damaging our health and our climate.

The working conditions in industry or on a steamboat were also tough and demanded a lot of people.

Every coin has two sides. This was also recognized with industrialization.

Steam engines used to be recognized from afar by their smoking chimneys.

To run a steam engine with little smoke, you needed good fuel and, above all, a good stoker. He had to take good care of the machine and keep it clean to ensure good exhaust quality. But he also had to constantly ensure that the coal was completely burned. As the fire burns better in good weather than in rain, he had to have a lot of experience to stoke the fire properly. The steam in the boiler was an energy store from which the steam engine consumed. The stoker had to recognize when more power was needed soon and start the fire well in advance. If less power was needed soon, the stoker had to recognize this and reduce the fire early on.

The thick, white smoke from the chimneys of old steam engines consists mainly of evaporated water. Water vapor is not dangerous. But the under the boiler also creates substances that mix with the water vapor and which are harmfol to living beings, plants and the climate.

Modern power plants and engines in cars and machines also emit pollutants. A lot of technology is used today to make the exhaust gases from power plants, cars and machines as clean as possible. However, power plants, cars and machines cannot be operated completely free of pollutants.

Incidentally, steam engines emit less fine dust and less nitrogen oxides than modern combustion engines.

Before the steam engine was invented, about 2/3 of all people worked on farms. That was important so that there was enough food. Other people worked as craftsmen. Everything was made by hand. Machines were not available. So there weren't any factories either. The first machines were operated with wind power. You all know the old windmills. Machines could also be operated with water power. You may also know old watermills. You were dependent on wind or water. There wasn't always wind. This is why craftsmen used to settle on rivers and streams. The first craftsmen specialized in manufacturing very specific goods with machines. So-called manufactories were established there. Only with the steam engine was it possible to have work done anywhere by machines. The factories could produce more and cheaper than individual craftsmen. The craftsmen were now afraid of being ousted by factories and managed to keep factories banned for a long time. It was only since 1810 that anyone in Germany was allowed to open a factory who had the courage, the money and the idea. Many factories specialized in certain products. In the beginning, a lot of workers were needed to operate the machines. These workers moved from the farming villages to the city. This change in the economy is called industrialization. Until the end of the 19th century, many people worked 16 hours a day - without a weekend. Despite all the work, they had no chance of a better life. Everything was more expensive in the city. Also, many things were worse than in the country. There was hardly any fresh food, social relationships broke down, and diseases broke out and spread quickly. Those who became unemployed became impoverished. Gradually improvements were introduced. Today, every worker In Germany has the right to a free weekend, vacation and insurance that helps him when he becomes ill or unemployed.

Working on the steam engines was very hard. Especially working on the furnace was hot and dirty. Gradually the workers fought for more rights and had to be paid better and better. Business became more expensive for ship operators. After all, the old steam engines emitted a lot of dangerous exhaust gas that harmed people, animals and our environment in general. All these points spoke against the further use of steam engines on ships in the first half of the 20th century.

By then, the diesel and gasoline engines had been invented and became more powerful over time. Soon the diesel engine was so advanced that it was suitable for the propulsion of ships. In the 1950s and 1960s, the diesel engine replaced the steam engine as a ship propulsion system.

You are now standing in front of such a marine diesel engine, which was built by Motoren-Werke Mannheim in the early 1950s. Propulsion of ships with such an engine required fewer personnel, was cleaner and did not take up as much space on the ships. Not only was the engine much smaller than a steam engine with the same power. Above all, there was no need for steam boilers, which had taken up a lot of space on steamers. Therefore, you had more space to take aboard passengers and load goods.

This engine you stand in front of soon became the common propulsion system for medium-sized self-propelled river boats.

The better beats the good.

Outwardly, such engines look very different from steam engines, but there are similarities. Engines also burn diesel with air, not much different than in the furnace of steam engines. But the combustion no longer takes place outside the machine, but in the engine itself. The expansion of the ignited mixture acts directly on the working piston in the cylinder. You saved yourself one step. However, the pistons in engines are only pushed down; they do not work in both directions, as in modern steam engines.

Another parallel can be seen in the crankshaft: the engine’s vibrations is being kept low using flywheels. Do you see that?

Internal combustion engines ran much faster than steam engines, but they didn't have that much torque. This motor ran at 1,000 revolutions per minute. That was a lot. Because the propeller is not supposed to rotate at 1,000 revolutions per minute, gears are usually used to reduce the speed. This allows the torque to be increased at the same time.

Starting around 1900, steam engines were gradually replaced by smaller and lighter internal combustion engines. Gasoline and diesel engines worked very well on cars or tractors. They were smaller and lighter. For locomotives, either diesel or electric motors were used. They were very efficient and, above all, cheap to operate. On ships, steam engines have been almost completely replaced by diesel engines.

Some ideas are so useful that many people understand them in a short time. Something new is emerging and replacing something familiar. This is called disruption.
Before the steam engine, horses did a lot of work. But no matter how well you fed a horse - the steam engine was more powerful and more durable. Therefore it prevailed. Soon there was a far lower need for horses, but also farriers, horse breeders and saddlers. Now, mechanical engineers, locksmiths and machine operators were needed.
The steam engine brought about a disruptive change for all of them.

That went not without a quarrel. Early steam boats were wrecked by boatmen who did not have steam engines aboard their ships. They were sceptical of the new technology and did not want to lose their jobs.
Many people are still afraid of innovations today. Nonetheless, ideas that were useful to people almost always caught on. You use streaming services to listen to music. Which one of you still has a CD player? Who knows what a cassette recorder or a tape recorder is? What's next?