Hey there SD,
I'm a Guard for South West Trains same thing as a conductor other than I don't sell tickets, Shift patterns are different depending on what depot your based at, I am based at woking depot and our base roster that we work to is normally you'll work 7 days of early turns starting between 05:00-07:00 then and can finish any where between 11:00-17:00 we then get 2 days off, come back to 7 days of late turnes starting any where from 11:30-19:00 and finishing between 20:00-02:30 or later then get 4 days off then back to 6 days of earlies then 2 days off then start the patteren again but alternate between lates and earlies but again this is depot dependent. Depending on what job content you have or what you are rostered you will generally work between 6 hours upto around 12 hours if your unlucky to pick up another depots work.
A normal working turn includes sign on time which is normally 10 minutes then if you do sell tickets then you get an extra 10 minutes sign on time to pick up and check your machine then you get a certain amount of walking time to get from the sign on point to the platform to pick up your first train at woking for example we get 5 minutes walking time from the signing on point to all platforms exculding platform 3 which we get 10 minutes as its right up the end of platforms 2-4, a PNB (Physical Needs Break or lunch break) minimum for us is 20 minutes plus 5 minutes walking time each way (30 minutes basically) and then you would sign off time at the end of you duty made up of walking time from the platform your last train arrives on back to the depot sign on point and then you get 5 minutes to put your machine away. Some jobs will also inculde Passing time (time you travel station to station but not working a train).
I hope this gives you a bit of an idea but for the training you will normally be working 9-5 or office hours until you have passed all your routes, traction etc but once you start with the company they will show you a base roster that they work to and all will be explained.
what depot will you be based at for southern?
Alan