Piggyback rig design

[26ftconical 1]

SkiD_PL8;
The Crossbow was the very first Parachute designed for the sport parachutist. It brought color choice to the sport jumper plus inovations that never existed. The people had a helluva time convincing jumpers that the piggy back was safer and quicker deployment of the reserve parachute. Aside from fact that all rigs today are piggybacks and that heritage came from the Crossbow and a gamble that Security took change sport parachuting. By the way you could do a 360 turn with the Crossbow in 1.8 seconds. It was a hugh leap forward. It could do everything the P.C. could do and could fly backwards 4 mph, the PC could do that.
Blue skies,
26ftconical

[JerryBaumchen 1,304]

That was great. You really took me back in time. For the '64 US Team, Brydon modified his harness to a split-saddle because he wanted one. In the photos taken back then you can see it, a sage green split-saddle that I am very sure he did himself at Ft. Bragg.
I bought a ParaCommander in the fall of '64 and the openings were damned hard. About six months later I put a X-Bo sleeve on it and the pain went away.
You guys really changed the skydiving world back then. I believe that the piggyback was the most significant change to sport gear in the history of the sport. And it was a dramatic change.

[26ftconical 1]

Jerry:
I assume you bought the sleeve from Eddie Brown. He would buy them from us 50 at a time. There was a Great Guy! We finally shortened the XBO sleeve to fit the P.C.
At Fresno in 1964, Herman Weber from pioneer was there checking the slots on the XBO to see if they were louvered. They tested the P.C.and XBO side by side the glide, rate of descent, the XBO had better brakes and cold fly backward. But the Xbo had this slight lateral oscillation. Looking forward to May 22cd.
Blue skies,
26ftconical.

[26ftconical 1]

Ladies and Gentlemen;
Security bought 10000 yds of low porosity 1.1 oz ripstop in five colors. Ludlow asked Dan Abbott what was he going to do with all that LoPo fabric. With the XBO the tracker are not selling we have had two orders for the Tracker rig and we still have a lot left.
Dan asked Ludlow if he had any ideas? Ludlow said I would like to jump one made with that LoPo cloth.
Dan OKed Ludlow suggestion and ordered a work order made up for one Test canopy. Ludlow added,"If this thing does what I think it will, itwill make one helluva reserve canopy. And that is how the 26ft LoPo came into being.
Blue skies,
26ftconical

[wartload 0]

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Pioneer was licensed by EFA, a French company south of Paris, France who had designed a towable parachute behind a boat or car. Pioneer called (it the) Paracommander and began trying it out for for jumping. The problem was it did not have brakes and if you laned it downwind, it was crunch time!

Just clarifying a point ... the original Paracommander was a towable para-kite used by water skiers, correct? It had no steering device when it was originally tried out for parachuting ... that came after the Crossbow canopy was revealed to folks affiliated with the US Team?

As a side note, I find it interesting to see how sport parachuting and hang gliding both have roots that extend a bit into the world of exhibition water skiing. Australians Bill Moyes and Bill Bennett used to water-ski launch Rogallo wings, then release the tow line and glide back down.

[26ftconical 1]

wartload:
The design and patents of the towable parachute were held at EFA France.
EFA licensed Pioneer to make the towable parachute in the USA. As with all towable canopiesthere were no brakes. Loy Brydon took the CROSSBOW informatiom to Pioneer.
Blue skies,
26ftconical

[pchapman 278]

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Part 18.
And walked away. Dan said the were having skirt openings and they instaneous high G opening. [...]
There was no amount of explaining that the forces they were getting had nothing to do with the harness, that it was the long Pioneer sleeve. They eventully got the Crossbow Sleeve

What was it about the design of the different sleeves that affected opening shock so much?

[JerryBaumchen 1,304]

First, you do need to know just how the canopies were built. Both had lines at the top (due to the pulled-down apex you could not hook a tension strap to the apex [think of a typical round canopy here], and I forget what we called them [whoops, just came to me, they were called Crown Lines]. Anyway, on the Pioneer sleeve these lines were left all stretched out above the canopy in the sleeve, just laying thre in the upper part of the sleeve. On the X-Bo they stowed these lines (just like you stow your suspension lines today) in rubber bands. I think that this stowing of the crown lines is what slowed the openings just enough to make the openings nice and soft.
So for today's quiz; what is a sleeve?

[wartload 0]

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So for today's quiz; what is a sleeve?

It looks somewhat like a very large version of a long-sleeved shirt sleeve. They were typically the same length as the actual canopy was when stretched out. These were slid down over the canopy, often with a flap at the lower end where the suspension lines were "S"stowed between rows of large rubber bands, then the whole thing was folded into the container.

The object of the device was to slow the opening sequence of the canopy--in particular causing it to inflate from the crown downward. It made for a much more docile opening.

If not correctly designed for the canopy, or if not present at all, the round canopy might start the opening sequence from the skirt--smacking your ass pretty hard against the saddle or leg straps.

(How'd I do, 26ftconical?)

[26ftconical 1]

Gentlemen:
There are two types of deployment of a canopy;
1. canopy first, lines second. With this type of deployment, malfunction can and do occur with a higher. what often occurs is the canopy start inflating before line stretch. If the filling is asymetrical (Off center), you can count on line-over malfunction. I have seen in testing when the canopy is lifted off the pack asuction occurs and the lines are unstow in masse. Line entanglements, burning as the tension is applied to the system as line stretch occurs. Line stretch is were the canopy mass has decelerated and the jumper mass is still the original velocity. The parachute system will stretch until the elastic force is reached the changing canopy mass is reaccerated and the jumper is decelerated and equilibrium is attain in the system. There are two forces on opening, line stretch and opening.
The smaller the pilot chute in mass(pilot chute and included air.) the less force in the line stretch and the greater opening force. The pilot chute has not decelerated the system sufficiently at line stretch. The canopy /include air have not been sufficiently. The snatch force at line stretch has to be increased with a more effective pilot chute. Stronger stowage loops or rubber bubber bands double will help prevent the lines beig sucked off the pack tray.
2. Lines first, canopy last. This requires the use of a sleeve or a deployment bag. The sequence Pilot extracts the sleeve or bag. The suspension lines are deployed under tension.Pilot chute bridle sleeve/bag lines, risers jumper. Tension is maintained from the pilot chute through the system during the deployment sequence. Strong rubber bands should always be used. The more the deployment sequence is controlled, the better the deployment with less the opening force. I prefer bags to sleeves and line stowage pockets nice and snug, uniform deployment and force is implemented with each set iof lines being unstowed. The stowing of the lines is more work, but it works better.
Blue skies,
26ftconical

[murrays 0]

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So for today's quiz; what is a sleeve?

Here's photos of the sleeve on my recently acquired 7TU C9....

--
Murray

"No tyranny is so irksome as petty tyranny: the officious demands of policemen, government clerks, and electromechanical gadgets." - Edward Abbey

[slug 1]

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So for today's quiz; what is a sleeve?

Here's photos of the sleeve on my recently acquired 7TU C9....

Hi Murry

Thanks for the pic's
For those that aren't out of date on sleeve's Note the reinforcing on the top of the sleeve. Some sleeve's were built better than others,a Some folks lost their pilot chute and top of the sleeve on opening due to "wear and tear".

Sooo for those unaware check the top of the sleeve for rot, etc, befor jumping or you could find yourself looking at a streamer

R.I.P.

[ahdz 0]

Some more pictures to illustrate this thread. [I'm open to corrections]

3 pictures of Lyle Cameron at the Scottish International Parachute Championships in 1965. Lyle is wearing and using a Crossbow ; another picture of the Scottish Team at that event sporting front and back rigs of the time

[JerryBaumchen 1,304]

Photo #3 shows him with a blast handle reserve ripcord rather than the original Lollypop handle. I'm not sure when Cameron got his X-Bo rig; I don't think he got one immediately upon the introduction. I also do not remember just when they changed from the Lollypop handle to the blast handle.
Anyone else out there remember?
Thanks for the photos.

[26ftconical 1]

Gentlemen;
Shortly after the world meet he got one of the US Team XBOs. He was an exponent of the XBO.
Blue skies,
26ft conical

[26ftconical 1]

Slug:
Both security and Pioneer came oout with a Piggyback with a removeable reserve. The Reserve pack was attached to the main pack with a heavy duty zipper. It was a gimick by Pioneer to sell Piggyback rigs. Security responded to keep them in check. The Pioneer design staff lacked imagination according to DanAbbott. He sead," They could design a roll of toilet paper without getting crap on there hands!
26 ft.Conical

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[ericfradet 0]

do we consider the guy on the right carrying the first piggy back, it looks like , is not it ?

[pchapman 278]

Looks like he is wearing a seat pack, and then perhaps a second seat pack somehow on his back, as a reserve on a second harness.

An interesting photo in any case.

[mlefebvre 1]

Good times!

This photo was taken at California City in 1982 above the Mohave Desert.

My Security Crossbow had a PC MK IV main and a 26' navy Conical reserve.

The MLW was too long and the 65 pound ill-fitting rig would often flop around putting me on my back.

I eventually upgraded (??) to a Handbury rig with an XL Cloud. (LOL)

[accumack 14]

The lollipop handle looked it came from the F1b opener!

 

 

[riggerrob 613]

 

According to www.riggerdepot.com/T-7--T-10-transition.html the first piggyback container was the XT-9.

" .. This static-line operated system was a bag-deployed piggyback system, with the main mounted on top and the reserve immediately below. While plans went back to April 1946, the first tests were not made until July 1950. ... "

Both main and reserve containers looked like smaller versions of their T-7 predecessors.

The XT-9 program was cancelled when the much softer landing T-10 was introduced. T-10 was widely used by NATO paratroopers for a good 50 years. If you have ever jumped a T-10 while wearing a rucksack, rifle and snowshoes, you will understand why the US Army tried to eliminate the chest-mounted reserve from the XT-9 harness. Hah! Hah!

The only time I have seen a main-over-reserve piggyback container was the "4-poster" experimental piggyback worn by Ted Strong to a precision landing competition in Snohomish, Washington back in 1999. Ted built that to allow him to install 3-ring releases on both front and back of his shoulders. He hoped that a wider (fore and aft) platform would improve stability during precision landings. Strong Enterprises never offered the "4-poster" for sale.

[JerryBaumchen 1,304]

19 hours ago, riggerrob said:

 

According to www.riggerdepot.com/T-7--T-10-transition.html the first piggyback container was the XT-9.

" .. This static-line operated system was a bag-deployed piggyback system, with the main mounted on top and the reserve immediately below. While plans went back to April 1946, the first tests were not made until July 1950. ... "

Both main and reserve containers looked like smaller versions of their T-7 predecessors.

The XT-9 program was cancelled when the much softer landing T-10 was introduced. T-10 was widely used by NATO paratroopers for a good 50 years. If you have ever jumped a T-10 while wearing a rucksack, rifle and snowshoes, you will understand why the US Army tried to eliminate the chest-mounted reserve from the XT-9 harness. Hah! Hah!

The only time I have seen a main-over-reserve piggyback container was the "4-poster" experimental piggyback worn by Ted Strong to a precision landing competition in Snohomish, Washington back in 1999. Ted built that to allow him to install 3-ring releases on both front and back of his shoulders. He hoped that a wider (fore and aft) platform would improve stability during precision landings. Strong Enterprises never offered the "4-poster" for sale.

Hi Rob,

Re:  This static-line operated system was a bag-deployed piggyback system, with the main mounted on top and the reserve immediately below.

The XBO system came on the market in the early Spring of '64.  Later, Summer/Fall of '64 there was strong rumor going around about the Soviets having tried a piggyback system in the '30's.  Apparently, the Soviet design had the main container on the top & the reserve container on the bottom.  The result was a number of fatalities, so they abandoned the concept.

Or it may just be urban legend.

Jerry Baumchen

PS)  When Security patented the XBO container design, they patented it for the reserve container on top of the main container, on the side of the main container & below the main container.

Edited December 1, 2021 by JerryBaumchen