Two Heavy Axles

Another closeup and the one last before I have to leave, shows the truck of class 140 freight engine. There are so many details that one can find on this... First of all, the brake assembly with the two brake shoes that are quite far from the wheel, as there is no pressure in the brake hose or the air tanks, and the handbrake is not set. Just under the engine frame, right in the middle of it, we can just make out the brake cylinder, which presses the shoes to the wheel through a lever system. In contrast to this, many American engines seem to have their brake cylinders on the side of the trucks, which was a suprise to me

We of course also recognize the sand container, and the pipe leading towards the rail. In case the wheels start to spin because they don't have enough grip on the rails (ice, snow, leaves etc.) pressurized air is used to spray some sand under the wheel and give you some extra grip. You probably knew all that, but if I'm at it, why souldn't I explain everything Sand is sometimes also used during emergency braking to increase the friction and avoid the blocking of the wheel, as that not only reduces the braking force, but also causes nasty flat spots on the wheel surface. Engines have to be taken out of service immediately if a flat spot is beyond certain limitations.
As this is an electric engine, you have to be careful not to overdo the sanding, as the wheels might lose the electric contact to the rails, which causes nasty sparks and loss of power due to the voltage fluctuations.

The flat box between the two bearings contains the induction coil for the PZB, which stands for Punktförmige Zugbeeinflussung. There are magnets on the sides of the tracks, that have a magnetic field of a certain frequency, which, when the engine travels over them, induce a current in the said box. Depending on what it is, the engineer has to push a button to show that he acknowledges the signal and will decrease his speed before reaching the main signal for example. If you run over a main signal that tells you to stop, the emergency brake is triggered, thus avoiding accidents in which the engineer didn't see a signal or something. OK, now I have to go, I hope I'm not boring you with my monologue

Oh, almost forgot the coils to our left! They are part of the air compressor, as it has two stages: It first intakes and compresses air to about 5 bar, and then sends it through the said coils to cool down. After that, the second stage compresses it to 10 bar, which is also the pressure in the air tanks and the pressure hose. The brake hose has a pressure of around 5 bar. OK, now I've got to run...