My question is what exactly dose it involve and are there career opportunity within?
A mix of electrical and mechanical maintenance. On a day to basis it's largely taking voltage readings, and checking that everything's as it should be. You'll be working on points (cleaning, checking for cracks, security, everything's moving as it should be etc), track circuits and/or axle counters, signals, and their power supplies. If you encounter something out of tolerance there'll be adjustments to be made, or perhaps replacements.
Some teams are combined faulting and maintenance, where you'll have to attend any faults which come in as well, which I personally find the most interesting aspect of the job, identifying what isn't working and why.
You'll do your fair share of look out duties as well if you're working red zone (i.e. while trains are still running). Operatives tend to do quite a bit of look out and driving to free other members of the team up to focus on arranging the work and COSSing, but a decent team should share this around as much as reasonably possible. Teams are typically 3 man.
There's always new things to learn, and no one is ever an expert of everything as there's such a variety of different assets. Gradually you'll get put on the courses to get the different competencies, although it can take a while. If you're keen and interested then once you get the competencies you've got the option of becoming technician, and then later team leader, although of course you can also branch out into other areas outside of general maintenance as well, such as renewals work.
Also I have no issue with shift working as I currently work in an industry where this is required but dose the pay/ shift allowances reflect this?
Nights and weekends are 10% extra (I think this is standard, but I can only speak with certainty for my area). Overtime can bump your wage packet up as well, although it's obviously not something that can be relied upon.
What is the company like to work for work life balance, benefits, holiday, pay etc.
The roster that you're on has a big impact on work life balance and how that plays out. If you're in an area that has 12 hour shifts then they're pretty rough to do as you're not left with much time once you've slept, showered, and eaten, but it does mean that you end up with more rest days, so it's swings and roundabouts there. Our roster is pretty good, effectively working out that we have one week off in every five, which is great, but every where's different, so that could be something to ask about at the interview stage.
You get some company benefits, but honestly I've never looked that much into them or used them. They're the typical things like the cycle to work scheme, some money off certain shops, etc. The pension options can be quite good.
Again, not sure if it's standard across the board, but my holiday allowance is 30 days per year, with New Years, Christmas and Boxing days the only bank holidays. There are a couple of other additional leave options possible, such as a day for moving house.
Sick pay isn't bad, which can be a reassurance. There are various lengths of full pay and half pay depending on length of service.
The reason I am asking all these questions as (fingers crossed it all goes well) I would like to make sure I am making the right decision career wise and find out as much information prior as possible.
Hopefully this gives a bit of insight, and all the best of luck!