Review- Samson's new "Mercury" kernmantle climb line (total A+!!)


Active Member
tl;dr -- This stuff should have a 50% higher MSRP (~$100 for 120' at Bartlett's maybe a lil less, that's entry-level rope pricing and this is verrrry premium stuff) 11mm, 6lbs/100' 32-strand kernmantle, 8500lbs ABS but with 3.5% elasticity that means its dynamic-strength is through the roof literally one of the highest dynamic-strengths of lines available right now!!


Some months back I wanted to make a heavy-duty rigging kit and in doing so had learned a TON about dynamic forces (and picked up a lot of disgust at how the arb-retail industry uses a static-strength paradigm when the vast majority of arb-rigging is dynamic) and was upset to find I'd been climbing a poly-core rope (1.4% elasticity Blue Moon, 6.5k abs) and went looking for a better, nylon-core, 3%+ rope. Mercury was the winner, I figured I'd "deal with" the coloration (wasn't a fan) but love it now, at any rate my online discussions Re arb-industry all but ignoring dynamic-strength in-favor-of static got enough attention that I found myself setting a phone-date with a Samson rep (best to omit names as I don't want him getting hounded lol) and while it was a great ~45min discussion on dynamic-strength/rigging/etc the coolest thing happened- he said he'd get me the Mercury *now* as he knew I was waiting til my Blue Moon wore out a bit more but was already fully decided on Mercury so can't thank him enough -- this was within days of Xmas so I imagine it was the xmas spirit that got my new friend to be so generous -- because instead of getting a 120' o 150' I got...more...which allows me to use it for all kinds of stuff, which I have been, so here's what I've found I would've written a review regardless (my Scheppach review may be up today as well actually :) ) but with the extra footage I was able to test even more :D

SO.... This stuff is great, the biggest gripes (well, the *only* "complaints") I could lodge are that it's not an easy splice (still haven't made one myself), and that an 11mm feels, well, like an 11mm!!! Have done a lot of thinking on "would I prefer a 1/2" rope in my hands if it means a heavier rope?" and cannot decide...
Everything else though, just outstanding!!! The 32-strand jacket is so smooth cammed ascenders move like butter, the 'hand' is great it knots easily and un-knots the same (yet knots don't slip) it's almost weird insofar as how firm it is w/o being stiff, like it moves/bends nicely in your hands but you could also hold-out a 1' section in the air and bend it and it'd keep that bend better than any ropes I've held. Have yet to 'fight' a knot out of this and it's been my go-to since getting it around xmas (wanted time to really test it out before posting, waited >3/4yr for my Scheppach review that's about to be posted :) )

This short article/video by Yale is SO amazing at illustrating how elasticity%, *alongside* tensile/static ABS, is a requisite factor/attribute when planning/rigging any system, I know this link's in my sig but can't encourage it enough if you haven't fully gotten it:
So...with that ^ in mind, you can see how it's (*very*!) inaccurate to say "Mercury is just 1/3rd stronger than Blue Moon", I mean sure that's true if you're lifting still masses off the ground, but if you're catching something falling then it's Mercury @8.5k // 3.5%, or Blue Moon @6.5k // 1.4%.......the math on these is still tough for me but that is a massive difference, would love if someone w/ a better handle on the math could put it in "real terms" for instance "a 200lbs weight can fall X feet without breaking Mercury but only Y feet before breaking Blue Moon", the difference is night&day.

On the note of dynamic-strength I have used it as a bull rope, we were just limbing a bunch of Oaks and figured it a good opportunity to try: instead of my 1/2" polydyne (3.5% elasticity as well) going through (3) x-rings, we used Mercury (no basal anchor just Mercury and a 3-ringed sling @the cuts) and did logs big enough I was jumping with them (obviously these were non-critical logs we didn't mess around when we got to the ones over his shed!) and, aside from noticing 11mm is 11mm, it performed exactly as-expected IE like my 1/2 polydyne. I think a lot of the "oh no that's too elastic!" thinking stems from a misunderstanding of the levels of elasticity and their relation to load-force, it's as-if people picture a 400lbs log going down to be snubbed and, at snubbing, it bounces-back-up! The rest of the rope world (rightly) considers anything ~<10% as a 'static rope', the arb world knows to stay away from ~0.5% dyneema products, but when it comes to choosing between Sirius(1-something-%) or Polydyne(3.5%) most don't seem aware at just how big a chasm there is between the two products, I can understand being wary of >5% cordage especially if you're climbing it on very long climbs like >50', maybe then you are able to feel a lil pull to it, but for routine arb-rigging just consider the following example:
I rig&cut a piece of wood from 2 different trees, the cut log is identical on both trees only with one tree I'm using a 1.5% line and the other I'm using a 3% line (oh the bounciness! :p ) Let's say the log is 30' off the deck, and is going to be snubbed right above a shed. Let's also say we're going to expose this rope to 10%ABS (which I'd argue is pushing things already..), that means that a **5 inch** difference in the height that log will come-to-dangle/rest, just 5" on a 30' run!! But the difference in dynamic-capacity or shock-absorption between a 1.5% and a 3% isn't minutiae it's huge (see Yale link if you want to do the math but it's not a few %'s it gets into magnitudes when you're going from <1% lines to >3% and pushing them to failure)

What else could I say? Have made all my lanyards/fliplines out of Mercury now, have also made some "squeezers" (treesqueeze configuration lanyards, very cool IMO!!), have a 90' bundle setup for being my 2nd-line when doing 2-rope SRT (ie two anchors/two ropes, still learning how to maximize use of this setup), have a 6-loop kit for knotless rigging (I use 5/8 bull rope as a rule but sick of using it to tie logs am trying to go fully knotless asap!) OH should mention Ice Tail because when I got my Mercury I also got Samson's catalogue and upon learning more about Ice Tail I had to try it, am now holding my 2nd order of Ice Tail (1.29/ft at Gap and they don't charge s&h :) ), at any rate Ice Tail "pairs" very, VERY well with Mercury, am guessing some are thinking "duh of course" but I hadn't pondered how the two cordages would interact but anyway it's great they're both so smooth that it doesn't jam yet it bites verrrrry sharp/quickly upon pressure (I use 2 prussiks when climbing though so an atypical review on prussik-performance is best I can do, sounds weird but I started out that way and never changed IE if setting-up a new system, when making hitches, a "hitch set" for me is just two hitches with one being like 6" longer of a loop so it can be in 'top position' on the rope, sounds weird but is fluid for me in fact I can't justify getting a Rope Wrench because I can go up/down/up without any hangups w/ my system already)

Well I may as well attach some pics of some of what I've made, gotta say this stuff is great total A+ cordage the no-splice and 11mm thin-ness may have me looking at Voyager or Vortex in the future as they also meet my elasticity, high-tensile, nylon core, by-yale-or-samson requirement lol but they're considerably more expensive -- and heavier -- lines so plan to stay on Mercury for a while and swap to one of those if, in a year, I'm still longing to splice (right now it hardly bothers me and I'm all about splicing! The reality is knots, on cordage this strong, simply don't bother me)
My 90' 2nd-line for carrying-up (I leave the Ice Tail on it, easier that way, the tail has a pair of quik-links inside its fig.8.with.bight and several feet of chafe sleeving there so I can just cinch/choke the line once in-canopy and immediately tether to the ring on that Ice Tail:

Here's the larger of the two 'squeezers' I made (TreeSqueeze lanyard configuration)
(^I'm fine&happy using Blue Moon for lanyards or anything where it won't be shock-loaded but for all intents&purposes my Blue Moon hank is now my rigging kit's "stiff 1/2 for speedlining" as I already have 3.5% 1/2" polydyne but figure the Blue Moon's stiffness will be nice for speedlining, mech.advantage, pulling etc :) )


Active Member
Oh and the bagging....sounds silly/trite but they(Samson) flakes the rope into the bag so when you get it it's ready-to-rock and for my main climb line I'm *still*, 3mo later, using the thick plastic bag it came in and just flaking it back in myself, had always thought that was cool :)

New threads New posts

Kask Stihl NORTHEASTERN Arborists Wesspur Kask Teufelberger Westminster X-Rigging Teufelberger Tracked Lifts Climbing Innovations
Top Bottom