26-03-2012 No more rules, but it hasn't got any easier...

Today as we are a day ahead, we have started the introduction to basic traction before I get to drive for the first time later this week (Wednesday!!)

I say basic introduction, but it was anything but!! Now I'm not mechanically minded but at the same time I have a basic understanding on how things work and I wasn't ready for what we were thrown into!

We have had to draw diagrams of all South West Trains stock. We have had to draw to show how power is supplied, where it goes, how it gets there, how it moves the train, where air goes for the brake, where it comes from, how it's used, and all this in one day!!

I have uploaded some photos I took of the diagram we drew for a four car Class 450.

now the lines are different things going round the train. To keep things simple (so that I understand it!) The black lines is main power that comes from the third rail via the conductor shoes. It does through some circuit breakers for safety before it goes to things called the TCU's (Traction Control Units) and ACU's (Auxiliary Control Units).

Now the TCU's have the simple job of making sure when the driver asks for power the train moves and it supplies and controls the power to the traction motors.

The ACU's are responsible for altering the 750v DC current that goes into to various voltages and sometimes changing it to AC current to power other onboard systems. It powers everything from the lighting and air conditioning to the toilets and public address.

The red and purple lines are how air is distributed around the train. Trains old and new need air to operate the brakes on older trains they do lots more. On Class 450 trains, the air is made in the compressor and it is distributed to all the coaches. The BCU (Brake Control Units) then do some magic so that when the driver wants to slow his train down the brakes come on!

They are also very clever so that when there is no air because of a fault or a mechanical break, the brakes are automatically applied with a spring, so you can rest assured that it is impossible for your train to run away!

This is just basic traction knowledge, we have our full two weeks on Desiro class trains later in the year after we have done half our driving with Driving Instructors and I must admit that's one part of the course I am now looking forward!

That's it for today. I have a nice easy day at Fratton depot tomorrow to learn how to prep and dispose of trains (it also means I get a lie in for a change!)

And then... FINALLY... we will get to drive a train in Clapham Yard on Wednesday... Not long now!!