Railway road to Darling: Info pls?

[Corne]

The plan is to ride from Bellville to Dwarskersbos on Saturday.  The challenge is to plot the route along the best dirt roads.  What can you tell me about the railway service road to Darling?  How do I get on it? GPS co-ords etc.  How far can you follow the road, and what's the condition? 
Would appreciate any pointers.  Sorry, I'm from out of town.

 

[Dusty Rusty]

 

[Crossed-up]

 

[Crossed-up]

 

[Beserker]

 

[Archangel]

 

[Corne]

 

[Mark62]