A Sand trap is an advanced, sand-based, retrievable anchor tool that can be used when there is favorable geometry and sufficient sand. As with all retrievable anchors, sand traps require practice and supervision by an experienced canyoneer before venturing out into a canyon.
The sand trap, originally called the MaxxiPad, was invented by Steve Woodford of Springdale Utah. He was frustrated with stacked sand bags getting stuck or bursting after falling down as well as the time it takes to set up such a system.
The original idea was to lay the sand trap flat and pile sand on it. He later realized it would work hanging from a lip by folding it in half.
There are three versions of the sand trap that are or have been commercially available (as of March 2016). While there are unique aspects to each version, they are functionally equivalent.
|Name||Manufacturer||Date commercially available||Currently available||Material||Weight||Manufacturer mentioned differences|
|MaxxiPad||Steve Woodford||6/14/2010||No||One piece design|
|SandTrap||Imlay Canyon Gear||12/7/2009||yes||18.2 oz|
| Sand Anchor
The manufacturer usually refers to it as a sand anchor, but has also called it a sand trap.
|Atwood Gear||3/20/2014||Yes|| 28.8 oz
The sand trap weighs 24 oz and the bib weighs 4.8 oz.
|Bib to help with wear and rope grooves|
Depending on the geometry at the rappel, the sand trap can be set up in two different configurations: taco and tostada.
Taco is the most common way to configure a sand trap. It is used when there is favorable geometry, such that the trap is pulled uphill when loaded.
Tostada is used when there is little to no good geometry, when the trap location is flat. The trap is laid flat and sand is piled on top. This configuration can hold more sand to make up for the unfavorable geometry.
There is a naturally wide safety margin for the sand trap. However, complications can decrease this margin and even make it impossible to rappel safely and retrieve the trap.
Factors that improve the safety margin
- Good geometry
- No sand or gravel between sand trap and ground
- Dry, light sand
- Decreasing friction on the retrieval rope by using rope protection instead of laying the rope on sandstone
Factors that decrease the safety margin
- Flat geometry
- Sand and gravel between sand trap and ground
- Obstructions that can catch the sand trap on pull-down
- Tight narrows with no room for sand to escape
- High friction on the retrieval rope
- Back up every rappeller possible every time.
- Have at least four or five people in a group in order to give the trap adequate testing before the last person has to use it.
- Do not build a sand berm and use the taco configuration - just use tostada.
- Sand bags can be used to shuttle sand to the sand trap location.
- A sand trap can easily be stored in a sand bag.
- Consider using 10' of leader rope between the retrieval rope and retrieval strap. The rope closest to the sand trap wears out more quickly and can be replaced without having to shorten the retrieval rope.
- If the slot is tight, the sand trap won’t be able to release the sand. Moving the sand trap back out of the slot to where it is wider will give it room to travel while it empties.
- It is possible to stack sand traps on top of each other, but it is only useful for guided rappels.
- Place rapides on the trap beforehand, one on the top edge tie-in points, one on the bottom edge tie-in points, and one on the retrieval strap. It is easier to clip the rappel and retrieval rope carabiners into the rapides than the webbing every time.
- No Kidding is highly recommended as a first sand trap canyon. It has many rappels and if there is a problem it is possible to exit after the first few rappels
- Adobe Swale is mentioned as a good sand trap canyon.
- Most other sand trap canyons are undocumented canyons around Lake Powell.
Forum thread with tips from sand trap users