just practice what they send you. the tests are designed so that anyone can take them whether you are railway already or off the street.
i say practice what they send you but the reality is the practice material is still pretty different to what you will undertake on the day.......this sounds blunt but it really isn't meant to so i apologise in advance........the assessments that you'll take aren't really meant for practicing anyway, it's more about having a natural aptitude to pass them hence why you are only given 2 lives or fails however you wanna look at it lol.
i hated the DFFT when i took it!...(but it's very passable)......my advice there is very much attention to detail, for example you could have the question absolutely bang on right but if you don't shade the box that it tells you to the whole question is wrong........i wouldn't say it's tricky it's more about reading the question correctly as certain things have to be checked in a certain order.....so very much attention to detail.
I honestly wouldn't worry about books mate, there used to be a time when you could break out the old physics books to help out with the mechanical comprehension tests but that is long gone.......i reckon you should just keep it simple and look at what they send you.....the last thing you wanna do is go looking at books for hours on end and then find on the day they've been of no use to you at all......although the actual assessments are different to the practice tests the principle is still the same
interviews are very competency based......can you think of a time when you have done this? such as time you have had to work to rules, A time you've had to use communication skills, A time you've been involved in an emergency situation those sort of things. I would say that is a particular area you should be ready for and have your answers in your head already.......we were given a sheet of paper at the start of the day with those type questions on it which we also wrote our answers on......then in the interview (which was last) they asked us more probing questions based on the answers we had given, such as what was your role in the emergency? what was the emergency? what was the end result? how did you react?what would you do differently?.
Now a lot of people make these answers up (not everyone has been involved in an emergency situation for example) the simple answer there is DON'T!!! it's all well and good making up the answer but it's when the assessors probe further on their answer and they've gotta keep the lie going they get caught out! these are well trained assessors remember they've seen and heard it all before.......if there's a scenario you just don't have an answer for be honest with them.....the chances are they'll ask you the question in a different way and you'll suddenly go "ahhhhhhhhhh i remember!!"
Not gonna lie to you as there is no point It's a brutal old day and you'll be shattered at the end of it but remember they are not there to fail you....they want everyone to pass.....the most important thing to remember is if you are not sure of anything ASK!....if they are allowed to answer the question or help you understand something in any way they will
good luck mate and all the very best although i'm sure you don't need it