Wow Thank you everyone. I have found some new online information and have made up a new plan based on what you have told me.
Please can you tell me if I have got this correct. I have based the track plan 5 on the image showing how the author thought the track was laid at the actual site.
If a train comes from A and travels to C then the east bound home and east bound starter are used . Points P1, P2 and P4 are set.
If a train comes from C and travels to A then the west bound home is used and point P4 and P5 are set for loop E. The train stops at the west bound starter.
If a train comes from B and travels to A then the west bound home is used and pointP3 and P5 are set. The train stops at the west bound starter.
If a train comes from A and travels to B then the east bound home and east bound starter are used . Points P1, P2 and P3 are set for loop D.
Looking at the enlarged map it looks as if the junction is just a double slip switch as per plan 3.
I have tried getting books for this line but have only managed to order one of them. The book will arrive at the end of the month, but I cannot wait that long as this puzzle is driving me mad. Designing a layout is really fun. The layout will be O gauge so this is the most I have room for. The road bridge would make an ideal scenic break.
Thank you for all your help.
Ken