John Middendorf designed the first stormproof portaledge technology back in the 1980's and 1990's, from necessity, as the pre-A5 portaledges of the day could not withstand severe storms, as John found out after getting pummelled by weather on the South Face of Half Dome in 1986 with Steve Bosque and Mike Corbett, which necessitated a daring rescue that saved their lives.

Since that time, John (the "deuce") has been fascinated with portaledge technology, first developing the A5 Design, and personally testing every iteration on the world's toughest big walls, including a prototype titanium version which he used on the first ascent of "The Grande Voyage" on Great Trango Tower, the largest and steepest big wall on Earth.  The A5 Design has been the de-facto standard in portaledges for the past 20 years, until the advent of John's new D4 Portaledges* (by BigWallGear), a series of revolutionary portaledge designs tailored for specific extreme adventures.

Starting with the full-size portaledge, John redesigned the frame with curved  corners and a hybrid diameter frame design, which offers more rigidity and higher strength to weight ratio, and with a innovative compact folding pattern making it the lightest, strongest portaledge ever, at 1/2 the weight and packed size as current versions of the A5 Design sold by other manufacturers. John then went on to develop the patent-pending open-source D4 "Bullet Joiners" which creates a super strong overlapping joint, and makes the assembly of the ledge in a hanging situation the easiest ever designed.  Not stopping there, the new D4 fly system, with its corner pocket design (eliminating the need for a drawcord) and single seam zippered "air-side" opening has provided huge advantages for climbers enjoying the view and weathering storms safely.

John then went on to tinkering with other shapes and sizes, which have led to the latest revolutionary design, the Delta2p, which is bound to become the new shape of portaledges thanks to finally solving a long-standing and complex puzzle of optimising strength, weight, ease-of-use, stability, suspension system and significant ergonomic advantages in its "perpendicular-to-the-wall" layout.

*Why "D4"?  I often get asked,  and gets jumbled with A5 (which is a climbing grade), and D5 (which stood for "Deuce5"), two brands I have been involved with in the past.  My nickname in Yosemite was "Deucey", coined by Grant Hiskes  who mangled my Friesland ancestral name "Middendorf" to "Dusseldorf",  and Deuce4 is my current "handle", so calling my current design line D4 just seemed fun.  Plus the original D4 portaledge had 4 curved corners, like the four curves in four "D"'s.