great link lizzie. good progress 
Yes they are to be congratulated for their 50 years in 2010 of being a preservation railway, as the first to use an old BR standard gauge line.
Once they complete the line from Sheffield Park to East Grinstead, so to connect with the London bound Rail Track system, it will be a major achievement 8-) 8-) 8-) 8-)
forgot that fact.
how many miles will it give them in total lizzie.
About 10.5 miles 8-) 8-)
about the same as the watercress line then. not too short a line now.
Indeed, and commercially just the right kind of length to make money, to keep maintained, and satisfy passengers, whilst giving good line space for the locos to be given their head and worked properly 8-) 8-)
unlike the midland railway centre, you cant do alot with 3.5 miles & 3 stations. not enough length to throw the regulator in the cab roof 
No, and not very healthy for a large main line engine that needs to be used fully

considering that they have the princess & duchess loco,s & a good collection of parafin cans, eg class 40,50 they could really do with 20 odd miles for them to stretch there legs.