Sterling ATS - a rappel device for canyoneering, reviewed


Sterling gave me an ATS, their new Pirana-inspired rappel device, to try out. Here is my report to Sterling (slightly edited):

Matt Andrews Sterling Ropes, Biddeford Maine August 31, 2010

Dear Matt –

Thank you for the opportunity to try out the ATS descender. I am a big fan!

Test Conditions

I have been able to get a few canyons in, and then we had an epic, and then we cleaned up after the epic which gave it a good workout. The log is:

- August 10 - Das Boot/Subway = 6 rappels, longest 20 feet. Clean.

- August 12 – Spry Canyon = 8 rappels, longest 165 feet, mostly clean.

- August 15 – Water Canyon (guiding) – 8 rappels, longest 100 feet, medium/clean.

- August 21 – Ticaboo Shelf Canyon – 6 rappels to 140 feet, dirty.

- August 22 – The Squeeze – 10 rappels to 100 feet, very dirty.

- August 23 – Cassidy Arch Canyon – 5 raps to 170 feet, clean but the rope was dirty.

- August 26 – The Wedge and Notch 1 Canyon Epic – 6 rappels to 180 feet, dirty.

- August 29 – The Wedge, clean up on Notch 1 Canyon – 6 rappels to 280 feet, very dirty.

Some notes on the style of these trips seem appropriate. Most of these trips used the Imlay Canyon Gear 8mm Canyon Rope, although August 21-23 used a brand new BW 8mm Canyon Pro AND a well-used Sterling 9mm HTP rope. Generally we mix up single strand and double strand rappels, though most of the longer raps will be on a single line. The Epic of Aug 26 included a 20 foot rappel on an Imlay 6mm Pull Cord, single strand.

All these canyons are in Sandstone, and most are quite dirty, where the rope gets wet and sandy, and extremely abrasive. Aug 26 and 29 involved a very dirty canyon, but it was dry, so the rope remained dry and was dry-dirty rather than the more abrasive wet-dirty.

In the past, I have used a BD ATC-XP (for low # raps canyons) and a Petzl Pirana in general. I have preferred the Pirana for the speed of attachment/detachment, friction options and rescue capabilities. At 190 lbs, I find the normal “2” mode on the Pirana does not provide sufficient friction, single line 8mm rope, and I generally use a left-leg-loop redirect biner to add friction and, on long rappels, an additional biner in the big hole of the Pirana to create a Z-rig. I rappel with Atlas gardening gloves and do not use an autobloc except when guiding.


The ATS provides considerably more friction than the Pirana and it took a little getting used to. I found the “1” and “2” settings produced almost the perfect friction level for raps on 8mm rope, double and single strand. I think it provides more friction because the rope path is more convoluted than the Pirana, and because the wider ‘waist’ provides more surface area that the rope runs across.

On the Aug 26 Epic, we ended up rapping the last little cliff band with the last bit of rope we had – a single strand of Imlay 6mm Pull Cord (actually, more like 6.3mm, and hard-woven static). Turning the ATS over, using the “2” mode, I was amazed that the ATS provided sufficient friction for this short, but steep rappel. Grateful too.

The ATS was fast to load and unload. All four ears are big and secure, making for tying off being quick and easy – which was very useful on the Epic.

I did not use the belay plate part of the ATS. We rarely belay as climbers in canyons.

Wear and Tear

Attached are pictures of the ATS after the canyons stated above. Wear has been acceptable. You can see a fairly deep notch in the upper left corner, underside, where a single-rope rappel runs. The first couple rappels took off the anodization color fairly quickly. Grooving elsewhere is mild and not consequential.

Use Problems

The biggest problem I found is that the left-side ears kept catching the hem of my shorts. And, just to be clear, these shorts are modern, long-shorts (almost to the knee). So like the Pirana, I tend to transfer it to my gear loop as soon as the rappels are finished. Hanging on the gear loop, it tends to “ring” more than other objects on my gear loop (but I think I can live with these micro-problems...).

Overall Opinion

I am a big fan. The ATS is a significant improvement on the Pirana, at least for me as I find the Pirana a little short on friction for my almost 200 lbs, using 8mm ropes single strand.

For lighter people, even in “0” mode it may generate too much friction. I see it not working well with 9mm and larger ropes, where a Pirana will work better. For guiding at ZAC, I see difficulty in getting 80 lb kids down the rope smoothly, even using single strand canyon pro rope (like we do when guiding at Zion Adventure Company).

Thanks for the opportunity to try it out, and to comment.

Available at the CanyoneeringUSA Store: Sterling ATS.