What Is Simul Climbing?

Simul climbing is a technique where all climbers move at the same time while tied into the same rope. Protection is placed by the first climber and removed by the last.

Simul climbing is fast because no-one stops to belay. This technique is most useful for alpine climbing on long, easy routes. It is also wise to simul climb on an exposed approach or descent where regular belaying would be impractical, and moving ropeless would be unsafe.

Simul climbing on alpine route
Climber falls simul climbing on alpine route

Simul climbing is an efficient way to climb, but it's also more dangerous. In theory, if the second falls, the leader will gorilla grip the rock with the speed of a ninja and hold their weight.

In reality, there is a good chance that the leader will be sucked, crotch first, into their last piece of gear.

The force on that piece of gear is far greater than in a normal climbing situation. This is because:
- There is twice as much weight falling on the piece.
- The second cannot give a dynamic belay because they are falling.

The force generated is much more likely to explode your gear from the rock. For this reason, it is not safe to simul climb on routes that you may find difficult. However, it is a useful trick to speed up your ascent of those long mountain scrambles, and is much safer than simply going ropeless.

Rock climber falls


How To Simul Climb

Start by climbing and belaying as normal. When the leader has climbed the full length of the rope, the belayer simply begins climbing. Leave your belay device where it is (see below). Make sure to climb at the same speed so there is minimal slack in the rope. When the leader reaches a belay, they attach their belay device and belay the second up as normal.

Although you can simul climb on a full 60m or 70m rope, it'll make your life really difficult. You're likely to get tons of rope drag (especially as you'll probably be on easier, wandering terrain) and it's hard to hear and see each other.

Make the rope shorter by having one climber tie into the middle and the other tie into both ends, or by coiling a bunch of rope away and tying into the shortened rope in the same way. You can tie into the middle with a figure-8, clove hitch or alpine butterfly attached to your belay loop with two opposing screwgate carabiners.

Alpine butterfly knot clipped to belay loop with two screwgate carabiners

Belaying While Simul Climbing

Belaying with a grigri when simul climbing

If the second wants to move a little faster for a short section, they can use an auto-locking belay device. Take in rope as you move faster, then give some slack out to the leader if you want to move slower again. As the belay device is auto-locking, you can take your hands off to actually climb.

Even if you don't have an auto-locking belay device, keep your normal one on the rope as it gives you the option to take slack in on a really easy (hands-free) section, or to quickly put the leader on belay if they reach a trickier part.



Simul Climbing Tips

- Make sure there is always plenty of gear connecting you to the rock
-Only climb routes that are well within the ability of each climber
-Always have the stronger climber second
-Communicate with your partner, especially when the second is stopping to remove gear
-Don't simul climb on a huge pile of choss
-Make sure to leave some gear for the belay
-Don't fall!​

Related Articles