The best bit of gear in this situation is the vocal cord, though it seems not everyone is aware of how to use it correctly.
Failing that, I reckon that before party number 2 starts heading up party 1's top-roping/shunting gear should be packed away (or party 2 given an invite to use it). For a multi-pitch climb, party 1's seconder has to be on their way or close to it. |