In reply to Trangia:
> I always understood it to mean that the leader leads the first pitch and brings the second up to the belay, the second then "leads through" and climbs the second pitch where he/she belays, and brings up the original leader who "leads through" again to the top of the third pitch and so on. it flows with each person leading an alternate pitch. If I understand it correctly "swinging leads" has the same meaning?
The way I understand the English, "swinging leads" or "alternating leads" is a strategy that describes how the climbing pair deals with the climb. An alternative is "block leading." "Leading through" is what the 2nd (new leader) does at the top of a pitch when you are alternating/swinging leads.
i.e.
"We climbed Trangia's eliminate, swinging leads" -> makes sense
"We climbed Trangia's eliminate, leading through" -> doesn't make sense
"I led through at the top of P3" -> makes sense
Post edited at 16:54