Experiment

[Hooknswoop 19]

OK, after getting side tracked on some rigging research, and trying to explain to Skycat why I have a riser in the freezer, here is what I found out:

If a 3-ring assembly gets wet (soaked), then freezes, the 3-ring won't release in a cutaway situation. 3-Rings have a huge mechanical advantage resulting in very little force being applied to the locking loop (type IIA, 400 lbs. breaking strength). That also means that it requires very little force to hold the locking loop in place, preventing the 3-Ring from operating (releasing). If the locking loop is soaked, then frozen, it will hold the small ring of the 3-ring in place. The 3-rings strength becomes it's weakness.

"OK" you say, but ask, "Who cares, how can this possibly apply to me, and why are you putting skydiving gear in your freezer?". The freezer part of the question was actually Skycat's. First off, the 3-Ring works very well. Pond swoopers are the most likely to be affected. Not many people will swoop a pond, in sub-freezing conditions, come up short, get soaked, pack up their gear, let it freeze, and then give it another go. But you never know. Again, figure the odds, but don't jump wet frozen gear.

OK, I'm back off to my Laboratory….….I mean loft. Anyone got a cheap Jacob's ladder for sale?

Hook

[mikkey 0]

This must mean don't jump with wet gear full stop. In many cases the temperature at altitude will be below freezing and if the loop is wet it could easily freeze in freefall. Am I right?

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When people look like ants - pull. When ants look like people - pray.

[SkymonkeyONE 3]

As someone who has been "frozen in a pond" I can tell you that regardless of consequence, we are gonna do it if it means doing well in competition. While I stayed much drier last November, Nathan Gilber still beat me even though he ate the pond five times in the meet. I was sucking, but he was SUPER SUCKING. He ran out of clothes five times. Anyway, as cold as it was, if someone would have had to chop, they may have encountered the problems Derek is relating. Bottom line: excessive exposure to freezing water sucks.

Chuck

[Hooknswoop 19]

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This must mean don't jump with wet gear full stop. In many cases the temperature at altitude will be below freezing and if the loop is wet it could easily freeze in freefall. Am I right?

The locking loop has to freeze enough that it won't bend and release the small ring. For all my tests, I left the riser in the freezer long enough for it to completely freeze. I don't think exposing a soaked 3-ring to freezing conditions for only a few minutes will have much, if any effect on the operation of the 3-ring. It is a fairly specialized set of circumstances that have to occur before it is an issue.

Hook

[hookitt 0]

I was right

heheh

My grammar sometimes resembles that of magnetic refrigerator poetry... Ghetto

[SkymonkeyONE 3]

Doooood! Frozen swoop ponds SUCK!

[skycat 0]

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I was right

heheh

That my boyfriend is a freak? Yes you were.

Fly it like you stole it!

[SkymonkeyONE 3]

I think you BOTH might fall into the catagory of FREEEEKYDEEEEK! Not that I haven't been in that catagory for QUITE sometime now.

[freakyflyr11 0]

first off i think it is very cool of you to do a experament of that nature and share it with us keeping us informend.second off you have way to much time on your hands!!!!!!!!!!!!!

[AggieDave 6]

Pond swoopers aren't the only ones that could be effected. Here's a what if for ya: Jumping in winter, you go through some precip, get your trash wet during your jump. Since its something like near 0F at altitude and still 25F on the ground, you might incounter this scenerio.

--"When I die, may I be surrounded by scattered chrome and burning gasoline."

[Hooknswoop 19]

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you have way to much time on your hands!!!!!!!!!!!!!

I know, I know. I'm working on that.

Hook

[Hooknswoop 19]

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Here's a what if for ya: Jumping in winter, you go through some precip, get your trash wet during your jump. Since its something like near 0F at altitude and still 25F on the ground, you might incounter this scenerio.

I thought about that. I don't think free-fall would be enough to freeze the loop enough. It just isn't exposed to the cold long enough to freeze. It might slow the release a bit, but probably not enough to matter.

Also, the more water in the loop/webbing, the longer it takes to freeze. The less water, the quicker it freezes, but the loop/webbing doesn't get as 'stiff'.
i think if it was a significant worry, it would have shown up in sport accident reports. The only refernce i found (and it was led me to the experiments in the first place) was 2 smoke jumpers in Alaska.

Hook

[mikkey 0]

I think you need to take the "wind chill factor" into account. The speed at which the cold wind hits you/your equipment does make a big difference. When I lived and jumped in Northern Europe in the 80's, I would in winter regulary land with a completely frozen moustache (it was the 80's after all ), especially when humidity was high and clouds around. Another example, the quickest way to cool a bottle of wine/champagne is to wrap it into a piece of wet news paper and hold it out of the window while you are driving your car. I know I am silly, but it actually works
So if your 3-ring is wet and you fall at say, 130 MPH at - 20 Celsius (don't know what that is in Fahrenheit) for say 50 seconds, then I could imagine the loop could freeze "stiff".

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When people look like ants - pull. When ants look like people - pray.

[Hooknswoop 19]

-20 C!!!!! Are you nuts! That is -4 F. You are right, wind chill plays a major roll in freeze times. I did find some research on the subject:

Estimated freezing times of the loop at 28F:
Wind speed(MPH) Freeze time(sec) 10% moist, 50% moist
15 460 2300
60 57 290
120 45 223

There are variables though, for example: the warmer the plane, the longer it wil take to cool the 3-rings. I don't think it is a big problem, even in colder climates, just something to be aware of.

Hook

[mikkey 0]

"-20 C!!!!! Are you nuts! That is -4 F. "

I see you live in Colorado - you must have these type of temperatures in winter? My coldest ever was a jump in winter in Scandinavia from 14 K. Ground temperature was - 10 C and temperature at exit - 40 C. That is cold (did wear balaclava and thermal clothing) You don't do it too often once you tried.
You are right in regard to this issue is low probability. So why are you playing in the freezer

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When people look like ants - pull. When ants look like people - pray.

[Hooknswoop 19]

I've done a few very cold jumps, didn't like it. Nothing below 0F I don't think. I read about it and wanted to see for myself, I like to tinker. Besides it drove Skycat nuts. I've done worse. I intentionally packed a line-ever (had 3 canopys) to see how feasable it would be to cut the line to fix it. It wasn't.

Hook

[mikkey 0]

I checked out your DZ web site - Derek: you don't look like the nutty professor after all

Your DZ looks nice, must be amazing views skydiving in the Rockies...... At some stage I want to do a skydiving trip to the US, i.e. CA as that is nearest to OZ, but the views in Colorado would probably justify a side trip

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When people look like ants - pull. When ants look like people - pray.

[JayhawkJumper 0]

Just as a side-note. I had soft housings on my rig when I bought it and wanted to get metal ones installed. You mentioned "tearing apart the rig". Mine was a Javelin so maybe a talon is different, but my rigger just cut off the old soft housings and installed the metal ones in about 20 minutes total. It's not that big of a job, at least on a jav.

[nacmacfeegle 0]

Hey Hook, while your in the Lab (visualising Frarnkenfurter from Rocky horror show)..
Take a look at how velcro behaves when its wet and frozen.....
I'm thinking about velcro that might easily get wet, say the wee tab on a main PC bridle.....or toggles
Also perhaps the velco on handles, which admittedly is less likely to get wet....

I've been led to believe in the past that wet velcro + freezing conditions = bad juju

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He who receives an idea from me, receives instruction himself without lessening mine; as he who lights his taper at mine, receives light without darkening me. Thomas Jefferson

[Hooknswoop 19]

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how velcro behaves when its wet and frozen.....

The velcro toggle worked fine, it actually hung up a little not from the velcro, but from the tab freezing to the hood covering it. Also, the velcro would be harder to freeze, protected from the wind chill.

Hook

[tombuch 0]

Interesting post... the topic of frozen cutaways was actually discussed about 20 years ago when I started skydiving and the three ring was just becoming popular. At the time I had a Security System with a weird release system that involved two rectangular pieces of hardware and a stiff piece of webbing that was threaded through, then held in place by the same kind of loop used on the three-ring.

One of the big problems with the system I was jumping was that in cold weather it would become stiff and lock up. The big part of the problem was the webbing, not the loop. The three ring remained functional even under adverse cold conditions.

Back in the day we did some tests by putting our rigs outside in the cold winter air and then activating the cutaway. The three ring was a kick-ass winner.

Now, I don't want to suggest that a three ring CAN'T freeze, but it is unlikely to happen, and that has long been an advantage of this system over others of the earlier days.

So, an interesting post, and a topic well worth revisiting.

Tom Buchanan
Instructor Emeritus
Comm Pilot MSEL,G
Author: JUMP! Skydiving Made Fun and Easy

[ERICCONNELLY 0]

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Anyone got a cheap Jacob's ladder for sale?

You can make one pretty cheap from a neon sign transformer. Be careful Prof, those things are wicked!

[SkyDekker 1,150]

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That my boyfriend is a freak?

Just noticed his last name, Dutch heritage, that'll do it every time

[billbooth 10]

Nothing works when it is frozen solid...except an ice cube. Cheers!