There are nineteen three wire bridges on the track.  Some of these crossings, it's pretty much the only way to get across in all situations.  On others, they they only have to be used when the river is high.  The most dangerous thing one faces on these tracks is flowing water.  Many people underestimate the speed and power of a river and overestimate their ability to navigate the rivers.  In general, if you can't see the bottom of the river, don't cross and if you have to go in flowing water above your knees, you had better think very carefully if you should be crossing or wait until the river levels lower.  That time for the rivers going down can often be a few hours but in Fiordlands, can sometimes be days if the rains keep up.

Three wire bridges allow a fairly wide river to be spanned with a minimum of equipment.  Wrap the cables around some trees, tighten them up and you have a bridge capable of crossing an otherwise deadly, impassable river.  Back in the day when I first was in Fiordlands, the bridges didn't have the metal brackets that the bridges do now.  In some ways the newer style seems too fancy if you ask me (and most people do).  Some people have asked what these bridges are like, so here are a few movies for your pleasure.  You know, I just checked link above to my first Dusky Tramp and I realized that I'm using the same backpack as back then.  Just a little bit of trivia that will change your life.

Thes third video isn't a bridge crossing, rather just a short stroll through the forest to show how the green never stops.