Just coming back with some findings for those of you who are interested.
We had an EMF survey done of the property. The train is not a problem as its a DC line & the magnetic fields die at 10 metres from the tracks. We are further than that & neither the tracks nor passing trains affected the field readings. There is no sound or vibration from passing trains, Infact we can't even see it so we found it hard to say when the train will pass & had to use the timetable instead.
However if the trains were AC powered then we were well within damaging distance!! So it really depends on the type of power of the train in question!
Also checked for substations, mobile masts, powerlines, airport radars & thankfully all were negative.
There were more significant readings inside the property - most of which had to do with wifi, Xbox consoles, radio clocks, cordless phones etc - which belong to the current owners so not our worry.
The big find was the induction job which showed alarming EMF & which we will be now swapping for a gas cooker! (More spend!!)
We also had our own microwave oven checked & it showed a bit of leakage (though its Bosch & less than 2 years old), so we were advised to replace it with a new one or get rid of it altogether.
Overall - an eye opener!!