smallest round to land into water?

[Calvin19 0]

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What is the typical speed of a 26' round? About 15ft/s? The speed after 33' jump is about 45ft/s, or 3x higher. To make the parachute descend at 45ft/s, its area should be 9x smaller, or its diameter should be 1/3 of 26', or about 9'.

Im no aerodymanitologiser, but how do you get those numbers? I would have no idea where to start to caluculate the drag of a round parachute. but, did you just find out the arithmic relative size with the area of the two rounds and speeds?

[460 0]

Steve Morrell (BASE 174) used to use a small triangular single skin parachute that is used for people who fall out of racing boats. He did freefalls from 90 feet with the parachute in hand. It had to be over water though because the thing was too unstable and landed too hard.

Looks like a death sandwich without the bread - Steve Deadman Morrell, BASE 174

[TomAiello 25]

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spinning round? i have not heard of this, does it spin as in around its verticle axis? the other 2 axis' stable?

Yes. It spins like a top. You have to put a swivel at the bottom of the lines.

More information (and lots of numbers for Yuri_BASE) can be found in the Knacke book. (edit to add: I've got a copy of that, too, if you want to look through it sometime.)

-- Tom Aiello

[email protected]
SnakeRiverBASE.com

[yuri_base 1]

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did you just find out the arithmic relative size with the area of the two rounds and speeds?

Yes, the speed is proportional to the square root of wingloading, so that a 9x wingloading = 3x speed. 9x smaller area = 3x smaller size, when scaled proportionally.

Maybe we can ask Maggot to drill an asshole in his manequin, I will install a pressure sensor and an accelerometer to determine if the round is big enough not to exceed the enema threshold?

Android+Wear/iOS/Windows apps:
L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
iOS only: L/D Magic
Windows only: WS Studio

[460 0]

NASA is currently hiring parachute designers etc for their next generation manned spacecraft, ie an Apollo-like craft with a parachute recovery system.

Looks like a death sandwich without the bread - Steve Deadman Morrell, BASE 174

[udder 0]

I thought it must have been done before. Would a very large hole through the apex be suffiecient to stop ocillation, with two rectangular cut-out extending to the edge on opposite sides to help slow spinning?

And there isnt any real need for a harness. Perhaps a wrist strap...

I thought it was pretty funny this got moved to the BASE forum. Maybe everyone else has given up thinking of stupid shit.

"In one way or the other, I'm a bad brother. Word to the motherf**ker." Eazy-E

[yuri_base 1]

Another idea: you stand on the edge of a bigwall (wearing BASE rig) and launch one of those powerkites used in kite surfing (with tailwind, of course) on a very long line. Kind of giant swing.

Android+Wear/iOS/Windows apps:
L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
iOS only: L/D Magic
Windows only: WS Studio

[zoobrothertom 5]

Thanks Yuri.
Rick Harrison sent me a video a while back from the early 80's of a jump off a moving train using hand held rounds. Main in one hand and reserve in the other. I need to double check his letter about the sizes, but the reserve was about a 10' round and the main wasn't much bigger.

____________________________________
I'm back in the USA!!

[jdatc 0]

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Another idea: you stand on the edge of a bigwall (wearing BASE rig) and launch one of those powerkites used in kite surfing (with tailwind, of course) on a very long line. Kind of giant swing.

There was a kite surfer out in Hawaii years back that got lofted about 200' by a thermal. landed with some bruises. It's on the web somewhere.

I've got an 18 meter kite at the ready if someone else wants to try it... I'll just shoot the video for the first one.

_justin

[yuri_base 1]

This one? 39 second flight

Android+Wear/iOS/Windows apps:
L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
iOS only: L/D Magic
Windows only: WS Studio

[Calvin19 0]

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Another idea: you stand on the edge of a bigwall (wearing BASE rig) and launch one of those powerkites used in kite surfing (with tailwind, of course) on a very long line. Kind of giant swing.

dude, before i even skydived i had a plan to bring my inflateble 17meter kite out to powell on our yearly trips, and fly it with short lines off the talles cliff i could find. now i understand how bad an idea that is, for reasons of physics, aerodynamics, and now i understand it would be illegal. i would not do that. so, i turned to paragliding. its safer

[padraigbrowne 0]

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I think if what you want is super small, and you can perfect the system (good luck), a spinning round would work best. Spinning rounds have much greater drag per area of parachute and are much more stable. Unfortunately, Department of Defense (i.e. very well funded) researchers have been unable to make a spinning round larger than about 8 feet that will deploy reliably (but maybe that's large enough for this application).
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Auto-rotating parachute system

http://www.atairaerospace.com/parachutes/heli-chute/

[460 0]

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Thanks Yuri.
Rick Harrison sent me a video a while back from the early 80's of a jump off a moving train using hand held rounds. Main in one hand and reserve in the other. I need to double check his letter about the sizes, but the reserve was about a 10' round and the main wasn't much bigger.

Dude, that's a 52 inch parainnovator pilot chute in the right hand and an 8 foot round in the left.

Looks like a death sandwich without the bread - Steve Deadman Morrell, BASE 174

[diablopilot 2]

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I think if what you want is super small, and you can perfect the system (good luck), a spinning round would work best. Spinning rounds have much greater drag per area of parachute and are much more stable. Unfortunately, Department of Defense (i.e. very well funded) researchers have been unable to make a spinning round larger than about 8 feet that will deploy reliably (but maybe that's large enough for this application).

Some somewhat related interesting food for thought here: http://www.atairaerospace.com/parachutes/heli-chute/

----------------------------------------------
You're not as good as you think you are. Seriously.

[JOY 0]

460 IS CORRECT. The train jump was in 1983 from a 300' high railroad bridge. Phil Smith jumped first and me 7 cars later. We used a 52" parainovator big mesh pilot chutes in the right hand and an 8 foot inverted center reserve in the left hand. The reserve was on short lines and we just connected the reserve by a locking carribeaner to our left large 3 ring. We held the skirt of the reserve and the 52 very tightly so as not to get drug off the train before we were ready and over the river since the train was doing at least 45mph. The canopies were both 16' diameter, inverted pulled down center parachutes in a free bag system. The mains were in Velcro Base Rigs that Carl Boensih and Smitty had. Boenish and Smitty owned the 16 footers. They were so light that it took almost no pressure to pull down a line to slip the canopy. On my jump, it was a white, very thin profile canopy and as I nearly approached the huge bridge column, I slipped it away from the concrete and nearly dumped all the air out of the canopy. I hit the water with a strong oscillation, knocked the wind out, but I was fine. The Engineer saw us jump in the rear view mirror and asked our on top photographers when they stopped 80 miles up the road if we made it OK and they said yes. Park Service hit us with Powerless Flight, but my Motion to Dismiss got both of us off. Boensih was filming from the cliff, PM Magazine filming from a helicoptor and Kevin Vennel, a friend who also jumped the train once, was on top with me filming my exit. The Good Old Days!!! Glad we lived through them.
Rick Harrison
BASE 38
[email protected]

[email protected]

[BASE104 0]

Rick,

I remember making quite a few jumps with rounds. Rich Stein had the same model as mine that he dyed black in his bath tub. I did a little antenna in LA with it. Phil had that Piglet made of F-111, and it rocked! I would always be low man and would burn that one down and Phil always took pictures. He was into the photography thing.

I saw George Roso jump a Para Commander from a 600 foot cliff over hard land. It was like going back in time, even in 1986.

In certain circumstances I liked the rounds better. They were good when you got open so low that there was no way to hit anything. When Phil and Andy jumped the Astrodome and Superdome, Phil said that they drop tested a square, which opened fast but flew into the stands. The rounds landed in the outfield. That is some funny video.

I guess if rounds were a good idea, they would still be around. Kind of strange how things seem like good ideas until someone shows why they are not. It freaked my rigger out when he figured out I had been jumping my reserve in a BASE rig.

As for size, Phil's definition of a valid BASE jump over water was whatever the world record high dive was. It was about 190 feet or something, and us, not being trained divers, could easily get whacked. I imagine you could make a pretty small one for water. How small, I do not know.

I had a lot of fun with rounds where it was warranted. I have this great picture of John Hoover open way above me with a square and my Preserve about half inflated a hundred feet or so off the water.

Mark

[Calvin19 0]

this would be pretty easy, all we need to do is find out how fast we hit the water at a 'safe' cliff jump feet first impact, im guessing is about 80 feet per second (with enema protection). and then we need to skydive with progressivly larger drouge chutes, to measure the speed at whatever weight, then try it off potato. how deep is that water at deepest point spring season?

i mean, ill try it.

[udder 0]

I will be hitting you up for whatever you find out. Imagine a dropzone at the sea, so much less training. Signifcantly cheaper equipment. No canopy collisions, or hook turn deaths. Inadvertantly exiting over land may be hazardous... But for anovelty dropzone it would be pretty funny.

Would it be possible to have the canopy like a mesh pc? With loading tapes instead of lines?

edit to add: the heli-chute by atair looks to be pretty impressive. And it packs up rediculously small. Sweet. I wan't one badly.

"In one way or the other, I'm a bad brother. Word to the motherf**ker." Eazy-E

[zoobrothertom 5]

Thanks for the correction

____________________________________
I'm back in the USA!!

[460 0]

don't drown.

to udder, i imagine the pack volume for a round with mesh and tapes would be immense.

to BASE 104, I miss John Hoover. I was at his funeral. If you have a picture of you and him, I would greatly appreciate a scanned image of it.

thanks
Chris

Looks like a death sandwich without the bread - Steve Deadman Morrell, BASE 174

[pope 0]

If the water's deep enough, you don't need a parachute for 100'.
if you must, a 22" PC would do the trick. I'd suggest connecting it from the tops of your shoulders though. Back in the day, we'd regularly do 85-110'. Now that I'm a BASE jumper, I think that would flip my shit out too much though.

[ryoder 1,382]

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spinning round? i have not heard of this, does it spin as in around its verticle axis? the other 2 axis' stable?

http://www.freepatentsonline.com/4844384.html

The Poynter Manual has a small drawing. It looks somehting like a child's pinwheel toy on a vertical axis.

"There are only three things of value: younger women, faster airplanes, and bigger crocodiles" - Arthur Jones.

[JOY 0]

Hey Mark. Nice to hear from you. I still have the old Patagonia red long sleeve pullover I traded you in 85 at Ardmore OK when we did the tower for PM Mag. Copy me on any scanned shot of Hoov and Chris if you have it to [email protected]. Tactically, rounds are safer close to a wall since they will not deflate if you hit one, but they land hard and can't travel to a good landing area if you need to. Now days, its as much about comfort and not getting hurt as opposed to just living through the jump.
Rick H.

[email protected]

[BASE104 0]

That tower was my last BASE jump. I was getting stupid and jumped a Sabre 150. I had a 180 and flew threw the wires...missing them.

I was all like, "What am I doing? I have a kid!"

Last time I climbed El Cap I had to go down a line in the dark to free a hung up rope. I was rapping down with my headlight lighting up this little spot.

I was like, "What the F am I doing up here? I have a kid!!"

That jacket was Phil Smith's. I don't remember whether he gave it to me or if I outright stole it from him.

I'll dig up some Hoover stuff and start a thread. We tortured our livers and packed a lot in the dark.

[riggerrob 558]

Nick,

I apologize.
I am the guilty bastard who suggested that a moderate move this discussion to the BASE Forum.
... something about me tiring of reading vague, speculative, ill-informed, overly academic ramblings by people who did not have a clue what they were talking about.

Just go ask the horse!!!

Maybe now it is time for moderators to move this thread back ... so average skydivers can hear from BASE jumpers who have jumped small rounds into water.