Steam Locomotive

The Steam Locomotive has revolutionized the world of overland transportation over the last 50 years. The vast improvement in speed and carrying capacity from horse drawn wagons and even the canal boats that grew in popularity throughout the Age of Sail has taken the world by storm. Steam Locomotive drawn trains have proven so successful that they threaten to replace marine shipping as the dominant form of transporting goods, as their ability to take more direct overland routes is often enough to make up for the added expense of fueling these mighty engines.

Development

The concept of rail-guided transportation systems is very old, but up until recently has mostly been limited to short distance haulage routes, most commonly in the form of the winched cart-and-rail system used in mining. After the development of the steam powered water pump, steam engines became commonplace in mines, and it didn't take long for mines to start running their cart systems using these same engines which sat idle during the dry seasons in the less flood-prone mines. This greatly improved output over the mule- and worker-cranked systems used previously, and this soon inspired ideas for further innovation.
The next development was the lightweight steam powered worker cart. This was a wooden railcart with seating for several workers and a small steam engine mounted on board that could drive the cart as fast as a person could run. These small engines couldn't handle the enormous weight of a steel cart laden with ore, but delivering a half dozen or so workers to their work site deep within the mine was readily possible, and workers would reach their posts fresh and ready. The lightweight construction of the cart meant that a work crew could readily lift the cart off the tracks to allow ore carts to run throughout their shift, then lift it back into position to ferry crews out at the end of the day. At first, it was believed that a reverser gear that would determine which direction the drive wheels spun would be sufficient to control speed, but after several close calls, accidents and a handful of serious injuries, investment in these devices was put on hold until a more reliable braking system could be devised.
Alongside this, designers began to tackle the difficulty of transporting the much heavier ore carts. The winching system was effective, but relied on a network of runners to signal the winching station to begin hauling, and with the rapid increases in output, this was now seen as too slow; thus independently powered carts were desired. However, fitting each cart with a steam engine capable of moving that cart and a seat for an operator to drive it would have greatly reduced the capacity of the carts, and increasing their length was not considered viable as twists in the mine tunnels were already the limiting factor on cart size. Eventually, someone proposed a train system that would incorporate an engine as large as a whole minecart, an attached cart of coal for fueling this large portable engine, and a system to attach several carts before or behind this pair. Thus was the steam locomotive born (in miniature, for as large as mine locomotives are, they are tiny in comparison to the behemoths used today). Fortunately, friction brakes were developed before the first of these devices was tested, as an under-loaded mine locomotive can move much faster than a horse at full gallop, a speed that would have certainly resulted in a severe accident had a brake-less test been conducted.
Some years after the mine locomotive became the new standard of mining operations, experiments began on using larger scale systems. It took 20 years of development to design a steam locomotive powerful enough to drive a train of carts large enough to be considered worthwhile, light enough to not waste most of its energy driving itself, and strong enough for the large boiler to not explode at the pressures needed to drive the locomotive at speed. Several rail lines had been developed, using horse-drawn passenger carts to fund the projects, in anticipation of this new method of transportation, and several inventors claim their design to be the first steam locomotive to transport goods and passengers from city to city, but with a speed of 20 knots on every trip (nearly 5 times the average speed of a sailing vessel and nearly as fast as a horse can gallop) being measured within the first year of its invention, it is clear that the steam locomotive will greatly change the world of overland transportation forever.