Short answer: Steady arms (locators) come as straight-tube (conventional lines), bent-tube (restricted clearance in tunnels - the bend frees headroom for pantograph lift) and limiting types (capping uplift on high-speed sections). The common slope standard is 1:5 to 1:10 upward (root higher than tip): when the pantograph lifts the wire, the force travels along the tube axis so the tube works in compression rather than bending - far more efficient.
Consequences of wrong slope
Too flat or downward: the tip sinks, creating a hard point or pantograph strike; too steep: stagger-holding ability drops. Bent arms installed reversed produce a reverse slope and an immediate strike risk. Current maintenance rules grade static angles (standard/alert/limit) - apply the line-specific regulation.