I will try to answer the questions kindly generated by members of this Forum.
Setrack code 100 ST240-1 nickel silver.
Frog dead or live. - Live.
Solenoid or hand operated - Hornby motor Mk1 R8014.
Switch blade - If set by hand, blade can stick. Set by motor firm connection to rail.
Faults happens on - the straight. (not located on curve rails).
Direction affects - both ways. More when traversing to the left (clockwise).
Location of points - not pinned to layout board. Rails either side of point, stuck
Track level - flat.
Underlay - none fitted through out layout.
Sound emitted by loco/coach. - Hollow clank rather than rhythmic clicking.
Movement of rolling stock crossing over points. - Slight move (both sides) and
Rolling stock passes over blade. - last.
Fault found worse when using rolling stock made by - Bachmann 158 DMU.