Now we are working on a loading cargo mechanics, but it will take a week to finish everything. That's why now is the best time to tell more about cargo delivery – our story is about train controls
First of all there is a power lever. It regulates how much steam is produced. The lowest position means that steam is not generated. The topmost position is a maximal steam production and you use a maximal locomotive power.
To control a pressure in a boiler you have a boiler gauge. When arrow reaches the red zone... I guess there is no need to explain what it means :)
You can see a train speed on the speedometer near the pressure lever. It is simple – in the most cases higher pressure means higher speed. But it takes some time for a boiler to produce enough steam, so speed is growing with some delay (sorry, steam locomotive works not in the same way as your Ferrari). The same is for the speed reduction. When you move the power lever down the pressure slowly goes down, and the speed also goes down.
Small gauges below the speedometer show you how much coal do you have in tender and how fast the coal is burning.
When you don't have a time to wait until the pressure falls dawn enough for a train to stop you can use the emergency hand brake. This way you stop your a train much faster, but you loose all your steam. It means you need some time again to produce enough of the steam to move your train.
Extra speed valve
When you need an extra speed boost, you can use a red valve, that gives an additional huge power for several seconds. I guess every real steam locomotive has it, but drivers just do not know about it:) Extra speed boost has some cooldown time as well very high speed may damage your train in turns, so you need to use it strategically.
Every train must have a whistle. It's very useful – you can scare farmers, greet dogs and wake someone early in the morning. Additionally to this you can frighten horses of bandits persuading you. The only drawback - the whistle consumes some of the steam and a locomotive loses the power. Anyway it is so funny to use the Whistle! Choo-Choo!