Fixe Triplex Bolts

[AlanfromOz]

Just a question in regard to fixe triplex bolts. One of the big advantages is the they are supposed to be easily removable.

However I've noticed there are 2 ways of placing them, which I think would effect the removability and/or strength of the bolt.

First: Terminology - I'm going to use the words stud (the threaded bit with the cone on the end), sleeve (the hollow thing with the shoulder on the end), nut and hanger.


The way Fixe say to do it is to put the hanger over the sleeve (ie put the hanger against the rock, put the whole bolt through it and tighten). This uses a 12mm hanger, and when you want to remove the bolt, you take the nut off, hammer the stud in then pull on the hanger to pull the sleeve off the stud.


The way most pictures on the internet show it, they put the hanger between the sleeve and the nut (a 10mm hanger that sit on the threaded bit of stud). This would make the hanger useless in removing the bolt, and you'd need pliers or similar to grab the edge of the sleeve. Similar to this pic (no sleeve sticking through the hanger):




My thought is that if the hanger is on the sleeve (as fixe show), would that lower it's pull-out strength (particularly in tension), because there'd be no "self-tightening" effect of the stud being pulled into the sleeve. Maybe I'm way off track with this though?

[potholer]

I wonder what difference in behaviour there would be if the hanger ended up slightly loose (in the worst case, in a situation where there was some cyclic side-to-side force from the rope attached to it).

If it was threaded on the sleeve, I guess it wouldn't be directly turning (and possibly unfastening) the nut, but would there be other problems arising - would it tend to wiggle the whole assembly out of the hole?

[hunter]

Where did you find the info from Fixe on bolt usage? I don't think I got anything with the ones I bought and I can't find anything on there website. I think that putting the sleeve through the hanger as you describe would seriously compromise the effectiveness of the bolt and I would not do so. It might work ok if you torque it to the recommended 44ft/lbs (I'm even skeptical about this) but as soon as it loosens I think it could come right out.

When I first got one of these bolts I placed it as shown in your picture, torqued it down, and tried removing it. No problems at all, it came right out. I think the only issue would be corrosion in the hole causing the sleeve to stick on an old placement.

James

[AlanfromOz]

Hi James,

Info from http://www.fixeclimbing.com/pdf/Libro%20tecnica.pdf. Page 10 clearly shows that the hanger is meant to go on the sleeve. I think this is the euro site (opposed to www.fixeusa.com).

I get what you mean about the thing coming loose - the whole anchor would rely on the nut staying appropriately tight. But if that's what the manufacturer says...

So you had no trouble retrieving the sleeve from the hole once the hanger was removed?


Alan

[hunter]

Very interesting. I agree with your interpretation of the instructions. I don't think I'll use their method though. I've just seen to many bolts loosen under the influence of weather and use (mostly climbing but a fair number caving) and I think it could pull out exactly as you originally suggested once loose. It's also worth noting that they recommend 43ft/lbs. Comparing a torque wrench to my regular 6 or so inch wrench the best I could do was 20-30ft/lbs. Maybe if bolts were always set to the correct torque they would not come loose as often.

So you had no trouble retrieving the sleeve from the hole once the hanger was removed?

No problem at all. The caveat being I just tightened it as hard as I could and then went through the removal procedure. Could be harder after a few years.

James

[AlanfromOz]

I'm not sure where you got 43ft/lbs from, but that pdf document lists the torque as 35Nm. I think this converts to 25.8 ft.lbs (torque = force x distance - ie 25.8 pounds using a 1ft lever, 56.2 pounds with a 6in lever)

One thought I had for a 'cave friendly' torque wrench was to calculate the length of spanner you would need to get the correct torque with your bodyweight. Eg I weigh 80kg, which is ~800N of force. T=F x D, 35 = 800D, so D = ~44mm. In theory I could get a spanner of the correct size, drill a hole 44mm away from the centre of the bolt hole and put a maillion through this hole. Tighten the bolt by hand, then clip my footloop to the hole with the spanner horizontal and stand in it (DON'T jump or bounce!). Repeat until tight. I'm not sure how it would work in practice, and is probably more complicated than it needs to be - especially when you said the max you could apply was 30ft.lbs. 'Do it up pretty tight' might be good enough.

I've heard of some people adding spring washers to the bolts (under the nut) in an effort to stop them coming loose... Comments?

I suppose if you didn't want to place the hanger on the sleeve but wanted the bolt to be easily removeable you could make up a bit of thin flat bar with a 12mm hole in the middle which could be used to lever out the sleeve.


My main application is for rescue anchors - where we want a quick, good anchor for short term use, and having it removeable avoids leaving unnecessary bolts it in the cave. I suppose in this case the likelyhood of the bolt coming loose is reduced because of the short term use, and after a heavy loading the hanger might be very useful to get the sleeve out (I read a bolt testing report where they couldn't get the sleeve out after severe loading - they had it installed in the same fashion as the picture). If you weren't intending to remove the bolt, there'd be no point in putting the hanger on the sleeve.

[hunter]

I'm not sure where you got 43ft/lbs from, but that pdf document lists the torque as 35Nm. I think this converts to 25.8 ft.lbs (torque = force x distance - ie 25.8 pounds using a 1ft lever, 56.2 pounds with a 6in lever)

I got 43 (actually 44) from here: http://www.fixeusa.com/triplex.htm at the bottom of the page although the units are wrong. Most bolts I have used have a torque of ~30.

One thought I had for a 'cave friendly' torque wrench was to calculate the length of spanner you would need to get the correct torque with your bodyweight. Eg I weigh 80kg, which is ~800N of force. T=F x D, 35 = 800D, so D = ~44mm. In theory I could get a spanner of the correct size, drill a hole 44mm away from the centre of the bolt hole and put a maillion through this hole. Tighten the bolt by hand, then clip my footloop to the hole with the spanner horizontal and stand in it (DON'T jump or bounce!). Repeat until tight. I'm not sure how it would work in practice, and is probably more complicated than it needs to be - especially when you said the max you could apply was 30ft.lbs. 'Do it up pretty tight' might be good enough.

Umm, I suppose you could work this out. Many manufacturers say max strength isn't achieved w/o proper torque. Basically I just checked that I couldn't exceed the recommended 30 ft lbs with a short wrench. I can't so I just tighten a bolt as hard as I can. This became a concern for me after a brand new bolt pulled out of a roof. I had tightened the bolt but not as hard as I could. Reset in the same hole and tightened with everything I had the bolt hasn't budged.

I've heard of some people adding spring washers to the bolts (under the nut) in an effort to stop them coming loose... Comments?

Hmm, couldn't hurt although it means you need more bolt sticking out. Mostly I think setting the bolt correctly is key. One good thing to do is after you have cranked the bolt down, clip in and hang off of it. Then tap it with the hammer a few times and tighten again. This simulates repeated loading and you frequently get another half turn out of the nut.

I suppose if you didn't want to place the hanger on the sleeve but wanted the bolt to be easily removeable you could make up a bit of thin flat bar with a 12mm hole in the middle which could be used to lever out the sleeve.

Seems like this could work. I can certainly see that the sleeve could get stuck although it hasn't for me. I'm just nervous about loading the sleeve like they suggest. To a certain extent I figure that I'd rather leave a stainless bolt in a cave than maybe compromise the strength of the bolt.

James

[ClimbBaja]

I'm a climber, not a caver, and stumbled opon this thread. The correct torque spec for the Fixe Triplex is 35 Nm (25.8 lb-ft).
The old FixeUSA web page had it wrong, showing 44, and in the wrong units of measurement "lbs/sq ft". At 44 lb-ft, the bolt would be dangerously over-torqued.

This thread addresses the installation of the Triplex:
http://www.rockclimbing.com/cgi-bin/for ... st=2191060

To quote myself:
"For safety reasons, the only way that I will use Triplex bolts is with the sleeve installed flush to the rock, not through the hanger. Use a 10mm hanger, and it can only be installed that way.
The Fixe-Spain website still shows the sleeve inserted through the hanger, facilitating easy removal. I was involved in discussions of the Triplex when it arrived on the USA market, including ASCA and FixeUSA. Our consensus was that the "hanger on top of the sleeve" (10mm hanger) would increase safety from pullout/tension loading if the nut loosened (which is a common occurrence)."

[ljthawk]

To quote myself:
"For safety reasons, the only way that I will use Triplex bolts is with the sleeve installed flush to the rock, not through the hanger. Use a 10mm hanger, and it can only be installed that way.
The Fixe-Spain website still shows the sleeve inserted through the hanger, facilitating easy removal. I was involved in discussions of the Triplex when it arrived on the USA market, including ASCA and FixeUSA. Our consensus was that the "hanger on top of the sleeve" (10mm hanger) would increase safety from pullout/tension loading if the nut loosened (which is a common occurrence)."

I agree with what is quoted. Similarly, when I first purchased a “set” of Triplex bolts they came with 12 mm hangers to go over the sleeve. You quickly learn this doesn’t work very well, it’s almost impossible to get the hanger tight against the rock and as previously stated does not “set” the bolt further on pull out loads (it would just pull on the sleeve). Back then and as already commented, Fixe changed their instructions and told me to use 10 mm hangers on the stud, not the sleeve.

Here is a document I put together several years ago when helping out the Southeaster Climbers Coalition with anchor maintenance. It has some illustrative pictures.

http://www.imdl.gatech.edu/ljthawk/fixe ... der_04.pdf

L.J.