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Blake's Hitch Tether/PAS


Original Post
t.farrell · · New York, NY · Joined Aug 2016 · Points: 60

Wondering if a Blake's Hitch tether is a viable option as a tether (and not wondering whether a tether/PAS is necessary - there are instances where I would like a tether and would prefer to keep it on the simple side/not buy specialty gear). Compared to a Purcell, it's less bulky and gives more range in the sense that you'd be able to get much closer to the anchor. I'm mostly unsure because I haven't really seen a whole lot of literature from the climbing community about the Blake's Hitch, but arborists seem to use it.

The photo below shows what the tether would look like. I couldn't figure out how to draw a weighted hitch, but the orange color is intended to show where the rope would be loaded. The slack loop grows as you shorten the tether.

Blake's Hitch tether
Gunkiemike · · Unknown Hometown · Joined Jul 2009 · Points: 2,745

Is this something you'd tie using the climbing rope? You're already Fig8'ed into that; you'd just need a longer tail (and a longer rope for those stretcher pitches.

High angle rope rescuers need an adjustable tether so they can be correctly positioned re. the litter etc. I have seen that they use specialized gear (Aztec kit, something like $100-200, IIRC) to facilitate this, but I wonder if they also use something simple like this.

Ryan Hamilton · · Orem · Joined Aug 2011 · Points: 20

It's hard for me to see what's going on here, not being familiar with it. But, if arborists use it, then it's probably a safe system.

My only caveat to this is that it adds a lot to what is already going on at the anchor and keeping things clean and clear at the anchor is paramount to staying safe. There can be a lot of rope and gear hanging at the anchor sometimes and having a simple PAS clipped to a master point can really help to make sure that you're safely clipped at all times. The other really good option is to just use the rope you're already tied into and clove hitch, or figure 8 on a bight to a locked carabiner on the master point. Both are simple options that make it easy to be clipped in and stay clipped in.

Nick Sweeney · · Spokane, WA · Joined Jun 2013 · Points: 650

That's an interesting idea and clever use of that hitch, but why do you need something like this? Using a clove hitch with the rope accomplishes everything that this does, and does not eat up all that extra rope.

John Wilder · · Las Vegas, NV · Joined Feb 2004 · Points: 1,530
Nick Sweeney wrote:That's an interesting idea and clever use of that hitch, but why do you need something like this? Using a clove hitch with the rope accomplishes everything that this does, and does not eat up all that extra rope.
This.
t.farrell · · New York, NY · Joined Aug 2016 · Points: 60

I was envisioning it with 7mm cord as a replacement for a Purcell or PAS.

Also,

t.farrell wrote:(and not wondering whether a tether/PAS is necessary - there are instances where I would like a tether and would prefer to keep it on the simple side/not buy specialty gear)
Joe Platko · · Unknown Hometown · Joined Aug 2012 · Points: 10

For a stand-alone tether/PAS, this looks like a lighter and less complicated alternative to the Purcell. I assume you would make it from 6 or 7mm cord (not climbing rope) with a Figure 8 on a Bight on both ends. The Fig 8 at the harness end could be intentionally long to girth-hitch to your harness and the other end lockered to an anchor. I don't typically use tethers, but if I did, I would try this.

Nathan Hui · · San Diego, CA · Joined Feb 2016 · Points: 0
Nick Sweeney wrote:That's an interesting idea and clever use of that hitch, but why do you need something like this? Using a clove hitch with the rope accomplishes everything that this does, and does not eat up all that extra rope.
I'm not the OP, but one answer I have to that is there are a couple TR routes that I regularly set up that have anchors set back a ways from an edge. If I put a short tether to the anchors, I can't get to the edge to work on the masterpoint or see the ground at the base of the climb. And because I'm walking to set the TR, I'm not tied into the rope, and at some point, I'm tossing the rope over the edge, and would much prefer to not toss myself over the edge. So an adjustable tether is what would be preferred. TBH, most of the time, I pretty much just set up a equalette or a quad and let it self-equalize, or set a fixed line and a prussik to work on a cordalette.

So now I pose another question to the OP: Why a Blake's hitch? Why not a tried-and-true Prussik? I assume you already have one on your harness as your hero loop/rappel third-hand. As people have already mentioned, if you're already tied in, just set a clove hitch. But, if you aren't tied in, and need a tether, then I guess you're effectively setting a fixed line and working from that, in which case I suggest just throwing a prussik on and closing the system. Or, clove hitch if you're not moving around too much.
Nathan Hui · · San Diego, CA · Joined Feb 2016 · Points: 0

Actually, now that I think about this more, I have another question.

How well would a Blake's Hitch catch if tied from 7 mm cord onto a 7 mm line? I thought for most of these friction hitches, you needed to tie the hitch from smaller line onto bigger line for it to catch. Would you trust it to hold body weight? What about a FF .5 fall? FF 1?

John Wilder · · Las Vegas, NV · Joined Feb 2004 · Points: 1,530

If you dont want to buy specialty gear, then just use a sling off your rack for a tether when you don't want to use the rope.

If you make this thing, it's essentially making a specialty piece out of 7mm cord- you're not going to use it for anything else. Even if you did, anything you would use it for, you can use a PAS for (anchoring, bail webbing, etc).

Is this thing viable- sure, I guess. But, like the Purcell, its kind of looking for a solution to a non-problem.

Joe Platko · · Unknown Hometown · Joined Aug 2012 · Points: 10

It might be useful for cleaning sport climbs when the chains are high and a sling is too short/long.

t.farrell · · New York, NY · Joined Aug 2016 · Points: 60

I'll throw out my intended use since I'm sure some are curious. Part of my job includes photography, and some of the requests involve precarious situations (leaning off of ledges, etc.). Since I'm already carrying heavy photo stuff around, I'd prefer to have a light, minimal bulk system to keep me safe. I'm not going to throw a climbing rope in my pack which takes up a lot of space/weighs a lot and also don't want to buy more gear. This is the solution I came up with for an adjustable, minimal gear/cost, low bulk tether. That is the specific scenario I was thinking of but as others have pointed out there are other situations.

As to why I wouldn't just use a prussik/sling, I need something adjustable. Unless ntlhui was referring to a prussik on a tether cord, which is something I thought of but I don't really want to cut up my cord for a small prussik.

Regarding falls/strength of the hitch, I have seen photos of a larger diameter blakes hitch on a smaller diameter line holding body weight. What I don't know is if it can hold a fall.

John Wilder · · Las Vegas, NV · Joined Feb 2004 · Points: 1,530
t.farrell wrote:I'll throw out my intended use since I'm sure some are curious. Part of my job includes photography, and some of the requests involve precarious situations (leaning off of ledges, etc.). Since I'm already carrying heavy photo stuff around, I'd prefer to have a light, minimal bulk system to keep me safe. I'm not going to throw a climbing rope in my pack which takes up a lot of space/weighs a lot and also don't want to buy more gear. This is the solution I came up with for an adjustable, minimal gear/cost, low bulk tether. That is the specific scenario I was thinking of but as others have pointed out there are other situations. As to why I wouldn't just use a prussik/sling, I need something adjustable. Unless ntlhui was referring to a prussik on a tether cord, which is something I thought of but I don't really want to cut up my cord for a small prussik. Regarding falls/strength of the hitch, I have seen photos of a larger diameter blakes hitch on a smaller diameter line holding body weight. What I don't know is if it can hold a fall.
For that? I'd choose a GriGri or a Ropeman and a rope tether- secure, infinitely adjustable, and way more friendly than mucking about with a friction hitch.
Seth Jones · · New Lenox, IL · Joined Feb 2015 · Points: 25
John Wilder wrote:If you dont want to buy specialty gear, then just use a sling off your rack for a tether when you don't want to use the rope.
+1
CrazyLegs · · Cincinnati, OH · Joined Jun 2014 · Points: 0

I don't think there is anything inherently unsafe about this Blake's hitch tether. I don't really think it would be all that less bulky than a Purcell prusik, but I can totally understand the advantage it has in its adjustability.

ntlhui wrote:How well would a Blake's Hitch catch if tied from 7 mm cord onto a 7 mm line?
Unlike most friction hitches the Blake's hitch is typically used to create an adjustable point on its own line. It works great for tent guy-lines! I don't see a problem with it being able to grip on itself, so long as you tie it with enough loops.

One thing to keep in mind though, most of the time we use 6 & 7mm cord, we use it as a loop instead of a single strand. Depending on the situation, and how you plan on using this, I wouldn't feel very comfortable using anything smaller than 8mm. If you have or know someone with some retired ~9mm climbing rope, I think that would be ideal.

The last thing I would worry about, and this is completely dependent on your situation, is what kind of exposure/ledge/fall potential are you dealing with? If this is something just to take your weight while you lean out of a window or something similar I'd say go for it. If there is a chance something could go wrong and you are freely hanging on this without any other means to get back to your anchor I would invest in something else that would allow you to travel up and down the line as needed, like a grigri and an ascender.

Good luck dude!
Nathan Hui · · San Diego, CA · Joined Feb 2016 · Points: 0
t.farrell wrote:I'll throw out my intended use since I'm sure some are curious. Part of my job includes photography, and some of the requests involve precarious situations (leaning off of ledges, etc.). Since I'm already carrying heavy photo stuff around, I'd prefer to have a light, minimal bulk system to keep me safe. I'm not going to throw a climbing rope in my pack which takes up a lot of space/weighs a lot and also don't want to buy more gear. This is the solution I came up with for an adjustable, minimal gear/cost, low bulk tether. That is the specific scenario I was thinking of but as others have pointed out there are other situations. As to why I wouldn't just use a prussik/sling, I need something adjustable. Unless ntlhui was referring to a prussik on a tether cord, which is something I thought of but I don't really want to cut up my cord for a small prussik. Regarding falls/strength of the hitch, I have seen photos of a larger diameter blakes hitch on a smaller diameter line holding body weight. What I don't know is if it can hold a fall.
Hmm. I understand your trepidation about carrying more gear. I do wonder, though, how much vertical exposure are you dealing with, and how much does this vary? Also, how much would this need to meet with any technical safety standards for work at height? As CrazyLegs said, if you are dealing with actual vertical terrain, you might want to look at other options that give you some self-rescue options.

One thing about this as opposed to a Purcell tether is, if you slip and grab at the Blake's hitch, you defeat the hitch, whereas if you grab the hitch on the Purcell, you don't defeat the hitch (if the adjustable loop is attached to your anchor). This might be a safety issue if you are dealing with significant vertical exposure.

Also, how long are you making your tether? If it's any more than a meter or so, why not use a fixed static and a prusik loop? For one, you wouldn't have a huge loop hanging off your harness if you adjusted the tether short, and you also now have the freedom to use the rope for as big a tether as you want, with the ability to switch to an ascent or descent system as you feel.
Brandon.Phillips · · Portola, CA · Joined May 2011 · Points: 55

Here is a commercially available tether for caving that is the same set up. This is made with static rope, but you could make your own with dynamic if it is something you were worried about.

onrope1.com/store/index.php…;id=425&parent=18

Ian Machen · · Fujiyoshida, Yamanashi , Japan · Joined Sep 2016 · Points: 35
ntlhui wrote: I'm not the OP, but one answer I have to that is there are a couple TR routes that I regularly set up that have anchors set back a ways from an edge. If I put a short tether to the anchors, I can't get to the edge to work on the masterpoint or see the ground at the base of the climb. And because I'm walking to set the TR, I'm not tied into the rope, and at some point, I'm tossing the rope over the edge, and would much prefer to not toss myself over the edge. So an adjustable tether is what would be preferred. TBH, most of the time, I pretty much just set up a equalette or a quad and let it self-equalize, or set a fixed line and a prussik to work on a cordalette. So now I pose another question to the OP: Why a Blake's hitch? Why not a tried-and-true Prussik? I assume you already have one on your harness as your hero loop/rappel third-hand. As people have already mentioned, if you're already tied in, just set a clove hitch. But, if you aren't tied in, and need a tether, then I guess you're effectively setting a fixed line and working from that, in which case I suggest just throwing a prussik on and closing the system. Or, clove hitch if you're not moving around too much.
If I'm worried about that, I will usually take my cordalette, figure 8 on the bight on the end, and tie a munter hitch on a carabiner clipped to my belay loop. Self belay myself to the edge, mule off, do my work. When I'm ready to come back in, I can do that too.
Carson Darling · · Cambridge, MA · Joined Jul 2015 · Points: 78

I've used a pair of Blake's hitches for my PAS in the past. With this setup, it gives me a rather large range of adjustability for the tethers, and I can set each one to a different length. I've had no issues with the hitches slipping, and with the extra barrel knots on each end, it's a closed system around the two lockers (aka if it slipped, it would still be connected to the locker).

One thing to be careful of with this setup is that if you make each of the arms too long, it can be easy to put yourself in a spot where you can't easily reach the knot to adjust them.

Using a pair of Blake's hitches to make a PAS
Josh Lipko · · Charlotte · Joined Jun 2014 · Points: 10
CrazyLegs wrote:I One thing to keep in mind though, most of the time we use 6 & 7mm cord, we use it as a loop instead of a single strand. Depending on the situation, and how you plan on using this, I wouldn't feel very comfortable using anything smaller than 8mm. If you have or know someone with some retired ~9mm climbing rope, I think that would be ideal.
This would be my biggest concern. If somehow the hitch worked itself free (unlikely when its weighted, i understand), you would fall onto the loop of slack that was created. Bad news for your back if you are using static material.
t.farrell · · New York, NY · Joined Aug 2016 · Points: 60

Reviving this thread to ask about something with Blake's Hitch/friction hitches in general.

Can I put a small piece of cord next to the rope the hitch is wrapped around to make a makeshift handle or does that compromise the safety of the hitch?

(Hitch is wrapped around one 7mm cord and one 7/64" dyneema loop)

Blakes around 2 cords
Guideline #1: Don't be a jerk.

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