How to control the engines
There are three different speed forward and one backward, the first speed forward 
and the backward 
speed half of the maximum speed of a normal minecart.
The second forward speed 
is same of the maximum a normal minecart, the third 
is the double of it.
All engine has a stop 
state, but the steam engine has an idle 
state, it stopped the train, but not the engine, so it keep the steam and burning the coal.
-
Lamp,
you can turn on/off the lamp on the engine -
Whistle,
you can use the whistle or the bell on your engine -
Redstone signal,
you can turn on/off the redstone signal sending, when your engine move through a signal track it activates it and can send a redstone signal, the signal button turn off automatically after you move through the signal rail, but the rail send the redstone signal when your train moving through that.
The electric locomotive works with power, it can contain enough power for twenty rails on any speed. It has a powerbar, so you can see how many rail left. You can refill it with a redstone powered power rail. It spawns with empty energy storage. Hint: you should spawn it on a power rail.
The steam locomotive works with water and coal. (Of course you can use any flammable item) You have three slots for water buckets and four for fuel. On left side it has two tank one for steam and one for water, they both have 2000 milli-bucket space. There is also a temperature gauge, when it is yellow, it reaches the 100 C° and start to create steam.
The diesel locomotive works with bio diesel fuel. You have three slots for fuel and one for the leftover item. On left side it has one tank, it has 2000 milli-bucket space. There is also a fuel gauge in side the engine figure, it shows the fuel level inside the pistons. You can use any combustion fuel, check the configurations.
You can control your train from the keyboard when you sit one of the carts. Y increase the speed, H decrease the speed, V turn on/off the lamp, B for whistle and N can turn on/off the redstone signal. With G you can get the information to the chat. You can configure them from the Settings/Controls/Key Binds BetterMinecarts section.
