Relevant drawings is C24865 – Atalanta 26 Arrangement of rudder uphaul and downhaul.
Friction is the enemy. On Helene the wires exit through the transom over a bolt. The bolt has lots of spacers on and importantly two sheaves. The wires had to be in the sheaves. If either the uphill or downhaul are allowed to go completely slack during raising or lowering the wires could jump off. You must keep light pressure on the one you are not pulling. Shockcord can be your friend here…