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sundevil777

Are "good" pins good enough?

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My rig is not overstuffed and suffered a bent pin, and I also am careful about leaning against things.



Have you considered there may have been a defect in your particular pin? I realize you have said several times you had a friend with a pin bent so bad it wouldn't extract but I think this is an isolated incident. Do you have pictures of the pin? Was it not able to be pulled by pulling on the pin alone or the handle as well? I can't imagine the pin being bent enough to not be able to be pulled by the handle if the rig wasn't over stuffed or the closing loop made way too short by the rigger that packed it. Either way it would be an error caused by someone, not necessarily a problem with the design or manufacture of the pin.

You have to understand, in order to change the pin design, a manufacturer has to believe they will make money or at least not lose money by changing the design. Assuming they aren't manufacturing their own pins, they then have to contact their supplier to have them research and create a new pin design. That costs money for R&D. Then they have to be willing to buy the pin (at an increased cost) in a quantity that makes fiscal sense for the supplier to even produce the pins. Considering this industry is not producing products at the rate other industries do(automotive, consumer electronics, etc) the increased cost per unit will be substantial until there is competition from other manufacturers. That cost is passed along to the end consumer...you.

So, lets say you are looking at two rigs. Rig A and Rig B both have similar features and have both been on the market long enough to be vetted and are trustworthy. You are leaning toward rig A because it has been around longer and there are more of them on the market...or because your buddy has one and swears by it. Rig A is $400 more and will take longer to get but you are willing because of whatever reason. Now rig A manufacturer decides to use the new, beefier pin. It's not a feature a lot of people are seeking, but it's "better". That pin adds $150 to the cost of the rig. Now you are at $550 to buy rig A. Maybe you decide on rig B to save the money and still get the pin. Now rig A manufacturer has lost your business. That is part of the decision making process.
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JohnSherman

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Reserve pins have to be soft metal because that allows the shank to be swaged onto the steel cable, where under great pressure the metal flows into the fibers of the cable for a tight grip. So I guess the trick is to have a pin hard enough not to bend, and at the same time, soft enough to be swaged. If you had a hardened steel pin, then you've got to figure out a new way to attach the pin to the cable...



Ripcord pins are made from .188 dia 302SS Cond A (303 is also allowed but I don't use it) they are then rotary swaged to a diameter of .094 using the rotary Swag process of cold forming as you can't harden SS with Heat treat. The overall length of the blade is dictated by the end user but is usually 1.25 inches. Column strength of the blade is tested by inserting it into an .096 dia hole one half inch deep and applying an 8 pound weight to the end. The results is checked in a go-no go gage of .104 dia to the full depth and the pin must fall out without friction after insertion.
This process and design was originally for a pin and metal cone thru a 9/16 and 7/16 grommet situation. The amount of allowable bend was critical as the thru hole in the cone was about a half inch deep/thick.
Today we use 1/4 inch grommets with a cloth loop. A far less critical arrangement.
Yes, the pin can bend in that configuration but it is usually from dropping or throwing the rig down or against something as the rig is compressed when it hits something and this causes the rest of the rig to want to expand causing a great load on the loop and subsequently on the pin causing a bent pin. The good news is that is can still be pulled even with a bend.
The Military still uses this pin on their center pull chest reserve with cloth loops and even with the rough treatment they get have had no problem.
Larger diameter pins would cause a harder pull with the same loop load. Additionally, the shank and cable would also have to be enlarged to obtain the necessary strength as the blade would still have to be cold formed to make it hard enough.
The thicker pins used on some assemblies have no greater column strength as they are not cold formed from a larger diameter. Don't let size fool you.



I think that the bending stress of a circular cross section varies according to the radius (or diameter) to the 3rd power, so the dimensions that you give for the pin before/after cold working mean that it would naturally have 8x less peak stress than the smaller diameter pin. Maybe my 'figuring is wrong. Does the improvement in strength due to cold working really overcome that 8x advantage?

Does a larger diameter pin have more friction based upon trying it? Normally such friction would not be dependent on the contact area I believe.

How much bend is tolerable - will result in really hard pulls? I think it is just too easy to say it is tolerable.
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mcordell

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My rig is not overstuffed and suffered a bent pin, and I also am careful about leaning against things.



Have you considered there may have been a defect in your particular pin? I realize you have said several times you had a friend with a pin bent so bad it wouldn't extract but I think this is an isolated incident. Do you have pictures of the pin? Was it not able to be pulled by pulling on the pin alone or the handle as well? I can't imagine the pin being bent enough to not be able to be pulled by the handle if the rig wasn't over stuffed or the closing loop made way too short by the rigger that packed it. Either way it would be an error caused by someone, not necessarily a problem with the design or manufacture of the pin.

You have to understand, in order to change the pin design, a manufacturer has to believe they will make money or at least not lose money by changing the design. Assuming they aren't manufacturing their own pins, they then have to contact their supplier to have them research and create a new pin design. That costs money for R&D. Then they have to be willing to buy the pin (at an increased cost) in a quantity that makes fiscal sense for the supplier to even produce the pins. Considering this industry is not producing products at the rate other industries do(automotive, consumer electronics, etc) the increased cost per unit will be substantial until there is competition from other manufacturers. That cost is passed along to the end consumer...you.

So, lets say you are looking at two rigs. Rig A and Rig B both have similar features and have both been on the market long enough to be vetted and are trustworthy. You are leaning toward rig A because it has been around longer and there are more of them on the market...or because your buddy has one and swears by it. Rig A is $400 more and will take longer to get but you are willing because of whatever reason. Now rig A manufacturer decides to use the new, beefier pin. It's not a feature a lot of people are seeking, but it's "better". That pin adds $150 to the cost of the rig. Now you are at $550 to buy rig A. Maybe you decide on rig B to save the money and still get the pin. Now rig A manufacturer has lost your business. That is part of the decision making process.



My pin getting bent may be due to a defect, and I will try to get it tested per the capewell spec later.

UPT implemented a new reserve pin apparently without nearly such a large cost increase, at least based upon how much more it costs to get a skyhook and all the newly developed stuff requiring investment for tooling and additional recurring costs for materials and labor. No analysis, but I think my conclusion is reasonable. Besides, the UPT pin could be used as is. Maybe that would hurt the ego of other mfgs, or maybe UPT wouldn't want to sell it.

My friend's rig with the bent pin - the reserve handle was pulled by the local rigger, and he pulled really hard until he got so frustrated and angry at the implications, that he just pulled on the cable like an RSL would. This was the early 90s, no pics and no measuring of the force.
People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am

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sundevil777

My friend's rig with the bent pin - the reserve handle was pulled by the local rigger, and he pulled really hard until he got so frustrated and angry at the implications, that he just pulled on the cable like an RSL would. This was the early 90s, no pics and no measuring of the force.



Why was he able to extract the pin by pulling on the cable, but unable to do so by pulling on the handle, which pulls on the cable? There would be a bit of extra friction from the cable running through the housing, but the better grip afforded by the handle should permit a much larger force to be applied than by pulling directly on the cable - more than enough to overcome that bit of extra friction, I would think.
"It's amazing what you can learn while you're not talking." - Skydivesg

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BrianM

***My friend's rig with the bent pin - the reserve handle was pulled by the local rigger, and he pulled really hard until he got so frustrated and angry at the implications, that he just pulled on the cable like an RSL would. This was the early 90s, no pics and no measuring of the force.



Why was he able to extract the pin by pulling on the cable, but unable to do so by pulling on the handle, which pulls on the cable? There would be a bit of extra friction from the cable running through the housing, but the better grip afforded by the handle should permit a much larger force to be applied than by pulling directly on the cable - more than enough to overcome that bit of extra friction, I would think.

Pulling kinda sideways - pulling on the cable allows a bent pin to function like a curved pin.
People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am

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sundevil777


How much bend is tolerable - will result in really hard pulls? I think it is just too easy to say it is tolerable.



Is there any interest in a comprehensive comparison test?

This test would compare a standard pin to a UPT pin, and I could make a UPT style pin out of 17-4 as well as a standard pin as a material comparison.

One test would be how much pressure does it take to make the pin start to deflect and get sucked into the grommet.

One test would be to do a pull force test at different stages of deflection with consistent loop tension. The pull force with a straight pin would be recorded, then the pin would be deflected into the grommet in measured amount increments, and pull tested at the original loop tension. This process would continue until a total failure to extract the pin is reached.

The cape well test would also be performed on all of the pins, with increasing weight to see at what point they each fail at.

There is also a fatigue test where the pins are bent 90 degrees each way until they brake.

It would be nice to have the tests done by PIA but I am swamped getting things put together for the show. I might be able to do some quick and dirty tests before the show, but nothing that could be published.

If there is interest, I could perform the tests and have the results published in Parachutist. I am not a pin manufacturer, nor do I have any association with any container manufacturer.

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sundevil777



UPT implemented a new reserve pin apparently without nearly such a large cost increase, at least based upon how much more it costs to get a skyhook and all the newly developed stuff requiring investment for tooling and additional recurring costs for materials and labor. No analysis, but I think my conclusion is reasonable. Besides, the UPT pin could be used as is. Maybe that would hurt the ego of other mfgs, or maybe UPT wouldn't want to sell it.



I disagree with your assessment of the UPT pin being universally compatible. In order to extract the pin via the handle the Velcro square holds the rsl part of the pin and the remainder that is swaged to the cable separates so it can pull through the housing. In the event of an rsl activation the pin is pulled at which time the pin separates. In order to install the UPT pin on a rig not equipped with a skyhook you would have to attach a small lanyard with the rsl portion of the pin attached so the pin could separate when the handle is pulled. If that portion is not attached via Velcro, then it is possible for it to inhibit reserve deployment if the pin reaches the end of that lanyard and the two pieces don't separate. If it is attached with Velcro in the absence of the skyhook system then you have a small lanyard velcroed to the rig attached to a portion of the pin and that part is lost when the handle is pulled. If the thing unattached from the rig during handling is it possible for it to inhibit the pin being pulled? Can the lanyard/pin assembly rotate in a way that doesn't allow the pieces to separate?

It is not a universal pin design without the skyhook being incorporated into the rig as well.
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mcordell

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UPT implemented a new reserve pin apparently without nearly such a large cost increase, at least based upon how much more it costs to get a skyhook and all the newly developed stuff requiring investment for tooling and additional recurring costs for materials and labor. No analysis, but I think my conclusion is reasonable. Besides, the UPT pin could be used as is. Maybe that would hurt the ego of other mfgs, or maybe UPT wouldn't want to sell it.



I disagree with your assessment of the UPT pin being universally compatible. In order to extract the pin via the handle the Velcro square holds the rsl part of the pin and the remainder that is swaged to the cable separates so it can pull through the housing. In the event of an rsl activation the pin is pulled at which time the pin separates. In order to install the UPT pin on a rig not equipped with a skyhook you would have to attach a small lanyard with the rsl portion of the pin attached so the pin could separate when the handle is pulled. If that portion is not attached via Velcro, then it is possible for it to inhibit reserve deployment if the pin reaches the end of that lanyard and the two pieces don't separate. If it is attached with Velcro in the absence of the skyhook system then you have a small lanyard velcroed to the rig attached to a portion of the pin and that part is lost when the handle is pulled. If the thing unattached from the rig during handling is it possible for it to inhibit the pin being pulled? Can the lanyard/pin assembly rotate in a way that doesn't allow the pieces to separate?

It is not a universal pin design without the skyhook being incorporated into the rig as well.

I agree that the UPT pin would require the other parts that go along with it, and have noted this earlier in the thread. I don't think the skyhook is needed, just the bits that are related to the RSL.
People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am

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but those bits could adversely affect the system and adds complexity in order to solve a problem that doesn't seem to be much of a problem. I know you are concerned about it, but there don't seem to be a lot of other people seeking a solution. with the vector pin setup you can close the rig and secure it with the pin while making it impossible to actually deploy just by leaving out one simple step. Its a good design if it's assembled right but there are pictures on this forum from not long ago where a totally unusable rig was found in the field and others commented that they had done the same but caught it before giving it back to the customer. I don't think adding complexity is a good idea. I have found numerous errors while inspecting a few reserves and they were simple things that could have caused injury.
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There is also a fatigue test where the pins are bent 90 degrees each way until they brake.



The military/government has no such test.
They do require this test:
When the pins are initially formed they have a blade length of about 3 inches. They are mounted to the cable then the end of the pin is bent 90 degrees. This bend makes attaching a holding fixture to the blade of the pin, for pull testing to 300 pounds, possible as a straight blade would have a propensity to pull out of a compression grip.
Some other folks were testing by "hook gripping" at the junction of the pin shank and the cable. This doesn't stress the blade which is required. This was a principal reason for pin failures getting into the field some years ago.
We have done loop load vs. pin pull force tests in the past and were convinced then of our current position.

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JohnSherman

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There is also a fatigue test where the pins are bent 90 degrees each way until they brake.



The military/government has no such test.
They do require this test:
When the pins are initially formed they have a blade length of about 3 inches. They are mounted to the cable then the end of the pin is bent 90 degrees. This bend makes attaching a holding fixture to the blade of the pin, for pull testing to 300 pounds, possible as a straight blade would have a propensity to pull out of a compression grip.
Some other folks were testing by "hook gripping" at the junction of the pin shank and the cable. This doesn't stress the blade which is required. This was a principal reason for pin failures getting into the field some years ago.
We have done loop load vs. pin pull force tests in the past and were convinced then of our current position.



The 90 degree test that I am talking about is a destructive fatigue test were it is determined how many times the pin can be bent 90 degrees, both directions from straight successively until it brakes. Obviously, softer materials traditionally will allow more repetitions than harder materials. My concern is the repeated bends (albeit little bends) over 15+ years of repacks and abuse from every day jumping, fatigues the pin over time. The destructive bend test will provide a comparison the other pin and possibly other materials as to how tolerant they are to being flexed many times.

Harder materials generally do not make as many bends as the soft material, but the harder martial is much more difficult to bend in the first place. I am expecting the standard pins to do well in this test, and they better given how they bend in the field.

The pull force test I was talking about is in regards to “bent pin” pull forces. A test fixture that allows, a controlled loop tension, the rip cord housing positioned as it is on a rig that a jumper is wearing, and has the ability to apply controlled force to bend the pin at the loop in controlled amounts would be made to conduct the test.

The first test would be with a straight pin with enough loop tension to create 20 lbs of pull force. That loop tension would be recorded so that it can be duplicated during the next tests.

Then force will be applied to the pin (concentrated over the same area as the Cypres loop width) and the pins will be bent into the grommet say in .010/.015 inch increments. The loop tension will be the same as the first base line test, and the pull force with a .010/.015 depression will be recorded.

Then the pin will be bent in an additional .010/.015 making the total depression .020/.030 and the pull test repeated at the same loop tension as the base line. This test will continue until a total failure to be able to extract the pin is reached. Every progressive increase in pull force and pin bend will be documented for comparison.

In addition to the pull force, the amount of force required to bend the pin each time will be recorded for comparison as well.

This test would be done on the standard pin, the UPT type pin, and I may make one of each out of a different material to see how they do.

Is this the test you are saying you did? Or do you mean you just did a loop tension vrs pull force with a straight pin only? Regardless, it would be great to post the results and clarification of the exact test parameters.

Please do not interpret me as being confrontational, that is not my intension at all. There seems to be this curtain between the jumpers using the gear the manufactures make, and the tests that the manufactures do, and we are told to, “trust us, everything is fine” but no one seems to be willing to support their claims with meaningful test results. This IMOP creates a cloud of suspicion that need not be there. Don’t you agree?

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I did not mean to hijack the OPs thread and stop debate on the subject matter.

So perhaps something that occurred to me last night might get the conversation going again.

I see many times in this, and other threads, jumpers dismissing a posters concerns about something on the bases that the presumed problem is "very rare" or "the instances where it has been an problem have very few" or "the problem is not big enough to make jumpers or manufacturers worry about it".

I am not good with statistical averages or actuary tables, so some one who is could provide a more accurate picture, but I will try to explain what I am wondering..

There are apparently two types of problems, perceived (low occurrence or importance), and recognized (independent of occurrence, but of high importance).

I would categorize the bent pin problem as a “perceived” one purely based on the responses to the OPs concerns, which seem to be dismissive based on the percentage of occurrences, and therefore not worth any effort or additional expense to deal with it.

Then I think about how many jumpers were killed (independent of reason) last year, out of how many million jumps, and it occurred to me that that percentage is probably much lower than the percentage of bent pins to the number of rigs that are out there. If one assumes that every jumper has at least one rig, that would be one pin per jumper, and the number of jumpers can be estimated I would think. I bet you could even estimate how many rigs have been made over a give range of time.

I doubt that the number of rigs built, or that are in service, are in the millions, but I may be wrong, I have nothing to base any number on. So I bet that the percentage of bent pins per total pins that are in service is higher than the percentage of deaths per total jumps in a year. (that could be worded better I know)..

If the percentage of deaths per total jumps in a year is indeed lower than the percentage of bent pins out of the total number in service, then the dismissal of a perceived problem, based on the low percentage of time that a perceived problem occurs, is not a valid argument. Now factor in that the perceived problem that the OP is pointing out is related to our absolute last chance to live, and the percentage argument really looses any relevance IMOP.

The Cypers was created in response of a fatality due to a bent pin. The OP has sighted that he observed a potentially identical outcome prior to the jumper boarding the plane. Bill Booth has a larger pin made for his rigs and he is known for solving problems and yet that seems to carry no weight.

“Is a problem only a problem when the body count gets above a certain number?” I know that is an extreme statement but that is what a non jumper friend said to me while discussing testing protocols.

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Bill Booth has a larger pin made for his rigs and he is known for solving problems and yet that seems to carry no weight.




Lots of points in your post. But in reply to just this one I will note that if you order a Vector without any RSL, as some people still do, it will come with a good old standard pin on a good old standard steel cable.
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The Cypers was created in response of a fatality due to a bent pin.



I was not aware of this, can you provide a reference?
People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am

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How many fatalities can you cite specifically where the cause was a bent reserve pin?

You made a point that Bill Booth has created a different pin design, but you didn't point out the fact that pin was specifically for the RSL system on the rig. The pin was designed to incorporate the RSL into the reserve deployment sequence. The pin was not designed to solve the problem of bent pins.

I have provided a few counter arguments but I'm not dismissive of the OP or his point. My question is, is this really a problem we need to address? Have there been fatalities using modern gear caused by bent reserve pins? This sport has a history of "fixing" problems that aren't really problems and causing problems with the fix. Some of these "fixes" resulted in fatalities where the original design that wasn't broken in the first place wouldn't have been an issue. I'm all for addressing a design flaw that is dangerous, but the current pin design doesn't seem to be one of those things to me. If a new design pin was offered as an option to solve the "problem" of bent pins, I would still opt for the proven design until someone else either dies or doesn't because of an unforeseen issue that was created with the "fix".

I personally have never seen a pin bent so bad as to create a total malfunction, and that includes the rigs at the rigger course that have been packed by low-skilled rigger trainees for who knows how long.
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gowlerk

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Bill Booth has a larger pin made for his rigs and he is known for solving problems and yet that seems to carry no weight.




Lots of points in your post. But in reply to just this one I will note that if you order a Vector without any RSL, as some people still do, it will come with a good old standard pin on a good old standard steel cable.



Yes, I believe you are correct. My above comment was not meant to imply that Bill Booth changed the pin he uses in some instances because he felt there was an issue with the standard ones, and I certainly do not want to create an impression of his opinion either way, that is for him to to say.

My intended point that I was trying to convey was that there are straight pins with a loop on the end available, and yet he decided to, for what ever reason, have his own pins made for his RSL design.

I look at that extra effort as being driven by something, and with out knowing exactly what it was, (could have nothing to do with the subject at hand in reality), because of his past performance I put some weight in his corner in regards to improving the pin rigidity.

It would be interesting to hear what the reasoning was not to use the available pins and have his own made.

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sundevil777

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The Cypers was created in response of a fatality due to a bent pin.



I was not aware of this, can you provide a reference?


How long have you been jumping? lol... :P

That story was very well known years ago. I thought maybe the story would be on Airtec's web page but it is not.

For newer jumpers who may not be up on their history, the AADs prior to the Cypres were mechanical and pulled the reserve pin. (I have no idea if there were other electronic AADs prior to the Cypres, but there may have been)..

These mechanical AADs were known to have a wide range of activation altitudes, but when maintained properly, worked fairly well, but sense it pulled the pin, if the pin was bent, the AAD could not pull it. On my first AFF jumps there was a mechanical FXC AAD in the rig with the dial on the hip.

My recollection of the story is that a close friend or family member, (someone feel free to corect me here) had a mechanical AAD and the pin was bent for what ever reason. Something happened during a jump that called for the AAD to open the reserve container, but it could not extract the pin because it was bent. The jumper died.

This motivated Helmut Cloth to do two things, one to find an alternative method to allow reserve pack opening other than the extraction of the pin, and two a better means of activation management, so that another jumper doesn't suffer the same fate from a bent pin.

The severing of the reserve closing loop was his method of choice to over come the bent pin issue, as it is an independent way to allow reserve pack opening. To control the severing of the loop, the results of his efforts was the Cypres 1, a microprocessor controlled AAD with a pyrotechnic actuated loop cutter, that provided an independent method for reserve pack opening.

If you are at PIA this year you should stop by the Airtec booth and I am sure they will be happy to tell you the story without the 100th hand in inaccuracies lol..

EDIT: I did just find a story here http://www.cypres.cc/index.php?option=com_content&view=article&id=98&Itemid=131&lang=en

And it is totally different than I have heard it several times. According to Airtec page, the jumper did not have an AAD at all.. Am I totally getting senile, or am I not the only one who heard the version of the story as I described it? I remember a post for Lee in a different thread about a pin that broke while he was closing a repack. The Airtec people were there and they asked him for it because of it's significance. I learn something every day lol..

My sincere apologies for any inaccuracies that I have posted based on years of folklore around the camp fire.

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mcordell

How many fatalities can you cite specifically where the cause was a bent reserve pin?



Does it take a fatality? No attitude implied, but isn't it the objective to be proactive and prevent it from getting to that point?

As I corrected my self regarding how the Cypres birth happened in the previous post, the only potential case that I can reference is based on the OP's account of a preboarding gear check, however, I am not a fatality data base, and the information we do get is sketchy at best.

They say 1 inch of ice will support a person, but if they slipped and fell is it not foreseeable that they might fall through? Given that foresight, is it not unreasonable to recommend that the ice be a little thicker before some one walks out on it? That is how I look at the pin, yes it obviously is working, but how much safety margin is there? Are we jumping with 1 inch of ice on our back?

mcordell


You made a point that Bill Booth has created a different pin design, but you didn't point out the fact that pin was specifically for the RSL system on the rig. The pin was designed to incorporate the RSL into the reserve deployment sequence. The pin was not designed to solve the problem of bent pins.



You are correct, I recall Bill Booth talking about how he never liked an RSL untill he designed his. With his system, the RSL lanyard is connected to the pin as aposed to a ring that the reserve rip coard goes through. This design was availale before the Sky Hook was available.

As I said in my above post, I did not intend to convey in any way that Bill Booth felt one way or the other regarding standard swaged pin strength or any issues that are being discussed in this thread. That is for Bill Booth to talk about.

Now that being said. Given what I know about Bill Booth he doesn't do something that could increase the complexity of a rig without a reason, what ever that might be. In the case of his choice to use a the thicker pin, his reasons might have had nothing to do with any of the aspects being discussed in this thread.

His RSL design uses a straight pin with a loop on the end and is not swaged to the cable. There were/are straight pins with loops on them available at the time that he was designing his RSL, and for some reason he decided to have them made for him as apposed to using the pins that were available. Why that is only Bill Booth knows, and it would be very interesting to hear the story. I have talked with Mr. Booth on many occasion and not once can I recall him deciding to do something that was not reasoned back to a relevant point. In the case of him having his own pins made, that are thicker, I have no idea.

mcordell


I have provided a few counter arguments but I'm not dismissive of the OP or his point. My question is, is this really a problem we need to address? Have there been fatalities using modern gear caused by bent reserve pins? This sport has a history of "fixing" problems that aren't really problems and causing problems with the fix. Some of these "fixes" resulted in fatalities where the original design that wasn't broken in the first place wouldn't have been an issue. I'm all for addressing a design flaw that is dangerous, but the current pin design doesn't seem to be one of those things to me. If a new design pin was offered as an option to solve the "problem" of bent pins, I would still opt for the proven design until someone else either dies or doesn't because of an unforeseen issue that was created with the "fix".



How one defines a problem is the key to everyone's positions on this and other subjects. We can't pull over when we have a problem with our gear once we leave the plane, so it is in our best interest to be as proactive as possible to avoid problems that can be foreseen.

You are right about there needing to be a balance between addressing one concern while at the same time creating different ones which may be more deadly than the initial concern.


mcordell


I personally have never seen a pin bent so bad as to create a total malfunction, and that includes the rigs at the rigger course that have been packed by low-skilled rigger trainees for who knows how long.



How many rigs have you seen where the free bag won't come out of the pack tray? They are known to exist and some argue that some jumpers have gone in because it that. My point is everyone posting in this thread are a minor percentage of jumpers, just because "we" have not seen something, doesn't mean it does not exist. Would you agree to that?

In reality the problem is lack of information. We as jumpers do not have any data on how rugged the pins are, and without data reverent to real life use, none of us can say one way or the other.

What I have proposed is a series of independent tests on the two pins that are used, to create a performance envelope that each pin can be expected to operate in with predictable performance.

It may very well prove that both pins are more than adequate and that there is a batch of them that are more prone to bend, just like there was a batch that tended to brake. This would explain why there are jumpers who say the never have seen an bent pin and two of my rigs that were made about 2 months apart have pins with depressions over the grommet.

How long were the pins that broke in use before the "problem" was identified? That is a serious question for anyone who knows, I do not recall how many or how long they where in the field.

It would also seem to me that the wearing of the dies was a progressive issue that gradually affected how the pins were made, so who knows, maybe these bent pins that some are saying they have seen were made just prior to the pins that brake?

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That is how I look at the pin, yes it obviously is working, but how much safety margin is there? Are we jumping with 1 inch of ice on our back?




Fifty plus years is a pretty long track record. I think the ice may be a little thicker than you are measuring.
Always remember the brave children who died defending your right to bear arms. Freedom is not free.

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gowlerk

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That is how I look at the pin, yes it obviously is working, but how much safety margin is there? Are we jumping with 1 inch of ice on our back?




Fifty plus years is a pretty long track record. I think the ice may be a little thicker than you are measuring.



I have not seen any measurements lol... but you may very well be proven right when some are taken.

One thing you said struck me... "Fifty plus years"... I don't think it is fair to count the time while cones were used. That loads the pins totally different than spanning the grommet with load in the center (generally). But even then your point still has a lot of years of applicable reference to sight… or does it?

Thinking as I type, how many other things that were designed back in the day are starting to be considered not up to every aspect of the modern sport? I am hearing more and more that the AADs were designed for old school jumping, and the modern "high speed" disciplines might push the AAD, or reserve system for that matter, beyond its limits, and that is possibly why some jumpers have gone in after an AAD fire. Of course AADs have not been around as long as pins have been spanning grommets, but one might say that 20 + years of AADs is a pretty long track record, and yet I saw 2 reps from a manufacturer openly saying that the AADs "might" be behind the times, or , "might" not be compatible with modern high speed disciplines.

I mention that reference not to redirect the thread, but it was the only thing that I could think of that really fit what I am thinking, and that is many people have posted about how the reserves have gotten smaller and the loops tighter over the years. Much like the introduction of head down "might" not be totally compatible with the current AADs that were designed based on jumping years ago, the introduction of smaller and tighter rigs with narrower closing loops compared to the traditional loops, might be stating to push the pin that has plenty of margin in a big soft container with a traditional closing loop, to its edge, and in some cases it will bend?

The more I thought about it last night, the more I am wondering how the “worn die” problem progressively affected the pins being produced. If there was a batch that made it to the field that were defective, who is to say there weren’t batches of pins with lesser levels of defect? These pins still might do well in larger and soft reserves with fat closing loops, but when stressed with the narrow Cypres loops, they might “tend to move and not come back”?

Thinking about it, the pin spanning the same size grommet is the only consistent thing over those years you have sighted, and rightfully so. However all things have not been equal from past to present. The introduction of the loop cutting AAD that required changing to a narrower closing loop that concentrates the load over a narrower point in the span over the grommet loads the pin differently than the wider traditional loops used up to that point. The introduction of the micro rigs (comparatively from back in the day) with over stuffed reserves which don’t give as much as a softer pack like John Sherman pointed out, and when worn and flexed, the pins are strained with additional load. The introduction, and common use of a power tool get the tight containers closed, and that generates enough power to bend the back plate in the rig allows the narrow loops to be tighter than ever possible when packing with just a pull up cord and ones hands.

So personally I would say in response, yes, there has been a long history of success with only a couple of outlying situations that most likely were the result of an extreme series of events. But over that time the conditions that the pins are expected to perform under have changed, demanding more of the margin just to maintain, and perhaps in some cases the margin is a little less than others which results in the OP starting this thread. In the past reserve systems were not questioned as being ablt to save you if activated above 750ft, but now that is not so much the case. Altitudes have been raised and testing is starting to be preformed to try to find out why reserve systems have started to fail their owners where in the past such happenings were the result of an extreme series of events.

My point is things change at levels that can easily be over looked, and individually might very well be inconsequential, but when you stack them all together, they very well might be using up more of the margin than we realize.

For example, the loop tension required to generate say 20 lbs of rig on jumper pill force is 100 lbs (just pulled that number out of thin air, not to be implied to be the actual tension), and after a over grommet bent test it is found that it takes say 150 lbs (concentrated over the with of a Cypres loop in the center of the grommet), then we have a margin of 50lbs to be used when the rig is flexed or what ever increases loop tension momentarily above the original 100 lbs.

It might be proven that it takes 200 lbs to start to depress the pin into the grommet to a point where it will not spring back. That would be a very nice margin. But if it only takes less than 150lbs (in this example only) then the margin is on the lean side. Without knowing what the loop tension is for a tight little rig to start with, and what it can reach when the container is flexed to an extreme, there is no way to determine how much margin we need to maintain, is there? I suspect from what John Sherman was hinting at is he has that data, and I imagine it is a trade secret, and as such, we will never know what loads are actually being put on the pins, and how much margin there is in the extreme reserve configurations. Without that data, the only thing we have to go on is past performance, and hopefully that performance will not claim any lives. I do not have a data base of fatalities to reference, as I doubt any of us do, at least with any accuracy. All we have are the reports of gear checks that probably saved a life to base this debate on. Even so, it is important that this debate take place. With out numbers, there are not any wrong points and there are not any right points. Each side of the argument has validity. Staying aware of the trends and being proactive albeit within reason, is all we are able to do in the lack of any real comprehensive data.

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I will be giving an updated version of "Everything You Need To Know About Ripcord Pins - But Were Afraid To Ask" class at the 2015 PIA Symposium. History, materials, design considerations, proper test procedures... It's pretty interesting and informative if I do say so myself.

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NancyJ

I will be giving an updated version of "Everything You Need To Know About Ripcord Pins - But Were Afraid To Ask" class at the 2015 PIA Symposium. History, materials, design considerations, proper test procedures... It's pretty interesting and informative if I do say so myself.



Good to know and sounds like a worth wile seminar. I would have liked to have some tests done prior to PIA, but getting ready for the show has me booked up.

I am sure I will be testing pins outside of the industry standard test procedures, and that is the point of them. All tests will be relevant to real use scenarios, so it will be interesting to see how the results compare to the “standard tests”.

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We are very interested in any information anyone has regarding any experience with a bent, or "deflecting", reserve pin.

If the pin batch can be identified that would be great, as would what container, size, and reserve size bellow it. (now I know that people are, shall I say, reluctant, to identify a container or manufacturer publicly, so feel free to PM me with the information). Also any pictures of the pins while packed would be good to have, place a straight edge on top of the pin for a reference.

Additionally, I am interested in exchanging some bending or, "deflecting", pins with new ripcords so I can test some pins that are deflecting and compare them to currently manufactured ones.

To qualify for this offer, the owner of the rig with a bent or deflecting pin will have do go through some hoops so to speak, such as first a pic of the pin as it is packed with a straight edge on top of the pin to give a reference, (this will give us an idea of how much it is deflecting), and type, size of the container, the reserve size, and date of last repack, number of jumps on current repack.

Then, if we want that pin, we want to take some pack density measurements prior to pulling the pin, (is the reserve a brick or a pillow), and some loop tension measurements as well, both static and with the rig worn and the body flexed in different, yet every day body positions, (this will tell us how the loop tension changes in that specific container set up as the container moves with the jumpers body).

Then we will pay for a replacement rip cord for that rig so we can take the deflecting one and put it through the gauntlet.

It is critical that the background data and history be documented properly in order for the pins to be compared to others.

The rip cord replacement offer will be very selective, as I can’t go around and replace everyone’s rip cords lol..

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