Use a tagline
Imagine you're leading a long pitch on a big wall. The anchors are in sight, phew, you’re almost done, and suddenly . . . the Bad Climbing Fairy suddenly clips a 20 pound / 10 kg weight onto your harness! Would you want to climb with an unnecessary 20 pounds on you? Well, that's going to be the approximate weight of your haul rope plus everything you need at the upper anchor hanging on you near the end of a pitch. Leading a long aid pitch is strenuous! Don’t make it even harder by carrying more than you need.
This is even more important if you are doing some free climbing.
Rarely do you need to start a pitch carrying a load like this! Send out that heavy gear up on the tagline later as you need it.
There’s a fair bit of gear that the leader will need when they arrive at the next anchor. This typically includes:
An anchor kit (at a minimum 4-5 locking carabiners, possibly a mini quad or PAS to make an equalized hauling anchor)
The hauling kit, either a 1:1 or 2:1, typically a locking carabiner, progress capturing pulley, and an ascender, for a bare-bones 1:1
The haul rope, which if it’s a 10 mm 70 meter long static rope will weigh around 5 kg / 10+ lbs (about 70 grams per meter)
Maybe a rope bag to put the haul rope in
Maybe a windbreaker, water, and snacks
Instead of schlepping all this gear on the back of your harness, instead climb the pitch trailing just a lightweight tagline. This is typically 60 m of 5 or 6 mm cord. At the lower anchor, this can feed out of a small designated stuff sack. When the leader gets to the next anchor, they pull up the tag line, which is attached to a small bag with all the needed hauling gear inside.
Note: the team needs to be extra careful with this tag line, otherwise it's going to be an unmanageable mess. It’s best to put it in its own designated rope bag.
High Mountain Gear and Gear Perspective both make excellent small rope bags that are perfect for your haul line.
The leader can carry a second small rope bag to store the tag line as thay reel it in.
The belayer must be sure this “tag gear bag” is ready to get hauled, unobstructed, and has everything inside it that the leader needs.
The medium Fish Beef Bag is a good choice to hold all the tag gear.
http://www.fishproducts.com/pics/beefbags.jpeg
The tag line can also be used to haul up any gear as needed when leading the pitch, such as that number 4 Camalot you might need up high.
If the leader needs gear sent up and they are more than 30 meters up and have a 60 meter tag line, their partner can use the haul rope to extend the tag line, and then can retrieve the tagline back down.
Note: It is super important that the leader not drop the tagline! At the upper anchor, good practice is to pull up some slack, tie it off somewhere safe, and only then unclip the locking carabiner connecting it to your harness, which is probably on the back of your harness and easy to fumble.
Using a tagline can dramatically lower the weight you’re carrying as a leader and free up some precious room on your harness. The one small downside is that it takes slightly more time to set up your “real” hauling system, but the effort you save is usually worth the extra time.
Keep in mind you don't need a fancy Dyneema core expensive tagline such as the Petzl PURline.
This 65 m, 6 mm static cord from Black Diamond would be a good choice.
