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Early Jumar Ascenders

Version A Version B Version C Version D
Version A Version B Version C Version D
 
Version E Version F Version G Version G
Version E Version F Version G Version H

Overview


Jümar Pangit was a Swiss manufacturer located in Reichenbach, founded by Adolph Juesi (Jüsi) and Walter Marti. Mr. Juesi was studying eagles for the Swiss government and needed to ascend on ropes in order to perform his work, so Mr. Marti developed the ascender for him. In 1958, they introduced the first Jümar to the climbing market.

Originally spelled "Jümar," the umlat was dropped in many countries that do not use umlats in their native language.

In 1982 I was in Europe on business. One weekend I drove to Reichenbach to meet Walter Marti, the designer and manufacturer of the Jumar ascender. Mr. Marti shared a great deal of information with me about his ascenders while his secretary, Mrs. Baumann, translated. Both Mr. Marti and Mrs. Baumann were very friendly. One thing thatI learned during the visit was that there are many variations of Jumar that were never put into commercial production. I also saw early Jumars whose cams had "Z" shaped teeth similar to those found on the early Clog ascenders. I am still looking for a pair of these for my collection.

Does anybody have a pair with the early z-tooth cams that you are willing to part with?
email me if you can help!

Here is a quick summary of the versions shown on this page:

  1. Wide handle
    (#1551)
  2. New frame design.
    (#1576)
  3. New cam tooth pattern.
    (#136)
  4. Colored safeties instead of cams.
    (#236, 1506, 1549, 1550, 2001)
  5. Gray paint
    (#36, 37, 272)
  6. Plastic safety.
    (#38pr+L, 293, 1574, 1911)
  7. Blue paint
    (#1535)
  8. Spring clip
    (#118)

The coverage presented here is by no means exhaustive. As usual, I will only describe the models I own.


Version A
(#1551)

Front Rear
Front Rear

Technical Details

I acquired my Jumar, Version A from Steve Brandlein in 2011.

Version A is 162 mm. tall, 76 mm. wide, 37 mm. thick, and weighs 190 g. The rope channel is 14 mm. wide. The cam radius increases from 42 to 57 mm. over an angle of 39°, giving a 24° cam angle. The tooth pattern is (4.5)^6(4.3)^2(4).

The inside of the right ascender has a riveted plate printed with:

APPARATEBAU
MARTI
Reichenbach i.K. Switzerland

Comments

This is the earliest Jumar in my collection. The wording on the plate is interesting, since it does not refer to the ascender as a Jumar. It lists the manufacturer as Apparetebau Marti, not using the later name Jümar Pangit.

The main difference between this version and the following one is the handle, which has a much thicker spine than the later versions have. This reduces the room available for one's fingers, although my large hand can still fit comfortably, unless I'm wearing thick gloves.

When I received these, they were rather corroded, but fully functional. and they cleaned up rather easily. The left and right ascender cams are painted red and blue, respectively. Most of the red paint has worn off my left ascender, but it is still clearly visible on the reverse side of the cam. A previous owner added some green paint to the left cam, and some green paint made it to the handle as well.

There are earlier Jumars with cams that have "Z" shaped teeth similar to those found on the early Clog ascenders, If you can help me find any for this collection, please email me.

 


Version B
(#1576, 2172)

Front Rear
Front Rear

Technical Details

I acquired my Jumar, Version B from Don Harper in 2012. I acquired another pair in 2017 as part of Bob Thrun's collection.

Version B is 162 mm. tall, 75 mm. wide, 36 mm. thick, and weighs 209 g. The rope channel is 13 mm. wide. The cam radius increases from 42 to 60 mm. over an angle of 41°, giving a 27° cam angle. The tooth pattern is (4.5)^6(4.3)^2(4).

Comments

Version B has a new handle design that allows more room for the fingers. Despite the reduction in the handle width, this version weighs 19 g more than its predecessor. I cannot account for the difference - perhaps the aluminum alloy is different?


Version C
(#136)

Front Rear
Front Rear

Technical Details

I acquired my Jumar, Version C at the NSS Convention Auction in 1999.

Version C is 161 mm. tall, 76 mm. wide, 37 mm. thick, and weighs 207 g. The rope channel is 14 mm. wide. The cam radius increases from 42 to 60 mm. over an angle of 41°, giving a 27° cam angle. The tooth pattern is (4.5)^5(4.3)^4.

Comments

The cam is slightly larger than the one in the previous version, and the tooth pattern is different.

This is an earlier ascender than Versions D and E, dating from the 1960s. It is mechanically identical to those, but the cams are color-coded instead of the safeties. Both safeties are anodized gold. The frame is painted with a speckled metallic gray paint instead of a uniform gray paint.


Version D
(#236, 1506, 1549, 1550, 2001)

Front Rear
Front Rear

Technical Details

I acquired my Jumar, Version D on eBay from Karla Green in 2008. I acquired a second pair along with the original slings on eBay from Simon Cox in 2009. I picked up two more pair, one from Charles Wilkes in 2010 and another from Chris Vandiver, in 2011, and a pair from Greg Estes in 2015.

Version D is 162 mm. tall, 76 mm. wide, 38 mm. thick, and weighs 210 g. The rope channel is 14 mm. wide. The cam radius increases from 42 to 60 mm. over an angle of 41°, giving a 27° cam angle. The tooth pattern is (4.5)^5(4.3)^4.

Comments

This is an earlier ascender than Version E. It is mechanically identical, but frame is painted with the same type speckled metallic gray paint as Version C.


Version E
(#36, 37, 272)

Front Rear
Front Rear

Technical Details

I acquired this pair of ascenders used from Roy Jameson at the 1980 N.S.S. Convention. They were originally purchased in the early 1970s. I acquired a duplicate pair from John Yost in 1993, and a left ascender from Karl Wilcox in 2009.

Version E is 161 mm. tall, 76 mm. wide, 38 mm. thick, and weighs 211 g.

The Jumar frame is an aluminum alloy casting covered with a gray epoxy(?) paint. The frame has a 14 mm. wide rope channel cast into one side. The handle is roughly rectangular. A 21.6 by 13.8 mm. rectangular hole in the base of the handle provides access for the sling ropes. A triangular hole above the cam provides an upper attachment point for auxiliary slings.

The cam is a skeletonized stainless steel casting. The cam and cam spring are attached by a 5 mm. semi-tubular rivet. A steel washer keeps the semi-tubular rivet from pulling into the aluminum frame. The cam face is very well designed, with a concave surface whose radius decreases from top to bottom along the cam surface in order to compensate for different size ropes. The cam radius increases from 42 to 60 mm. over an angle of 41°, giving a 27° cam angle. The conical cam teeth are aligned perpendicular to the cam face. The tooth count is (4.5)^5(4.3)^4. The cam safety and safety spring are mounted on a 4.5 mm. pin located about half way down the handle. The cam safety is a piece of anodized aluminum, red for left-handed ascenders and blue for right. This color coding has been maintained on all later model Jumars . The cam safety physically blocks the cam from opening far enough to allow the main rope to slip out of the rope channel. Rotating the cam safety towards the base of the ascender provides clearance for the cam to open completely.

Comments

The Jumar began to appear in American caving circles in the early 1960s, and has probably remained the most popular mechanical ascender since that time.

This model, like all Jumars, is very well made. All parts are finished, and there are no sharp edges exposed anywhere. "Gray" series Jumars are probably the easiest handled ascender to operate one-handed. There is little if any difference in difficulty in using either hand. My technique is to open the safety with the middle finger, then open the cam with the thumb (of the matching hand) or forefinger (of the opposite hand). The entire sequence reduces to one fast, fluid motion with very little practice.

The major drawback of the early Jumars is the method provided for sling attachment. The correct method involves bringing the slings up through the square hole in the base of the Jumar and around the back of the handle. THIS IS NOT A COMPLETE DESCRIPTION SO DO NOT TRY THIS WITHOUT INSTRUCTION! It is unsafe to simply loop the sling through the handle, since this places the load on the thin, weak area at the base of the front strap. The front strap (brace) can then break under tension. There have been several reports of ascender failure resulting from this mistake (Davison, Don Jr., Hits and Near Misses, N.S.S. News, v 34, #5, May, 1976, p. 80; Davison, Don Jr., Hits and Near Misses, N.S.S. News, v 35, #4, April, 1977, p. 73). It is not clear whether the broken Jumars were Version C, B, C, D, or some other version. Eventually the 78 (yellow) series Jumar was developed to eliminate this perceived problem.

The color coded safety on the Jumar is nice, and suggests an even more practical idea: color coding one's left and right foot slings. Because of the universal availability of the Jumar, the red=left, blue=right scheme is an obvious choice. Old-school Petzl users might prefer a yellow left sling instead.


Version F
(#38, 293, 1547, 1911, 2171, 2173, 2174)

Front Rear
Front Rear

Technical Details

I acquired this pair of ascenders from Speleoshoppe at the 1976 N.S.S. Convention. I acquired another pair from Dean Berkbigler in 2009, and a third from Alexander Medrano in 2011, all on eBay. I acquired three more pairs in 2017 as part of Bob Thrun's collection.

Version F is 157 mm. tall, 74 mm. wide, 36 mm. thick, and weighs 206 g. The rope channel is 14 mm. wide. The cam radius increases from 42 to 60 mm. over an angle of 41°, giving a 27° cam angle. The tooth pattern is (4.5)^5(4.3)^4.

This version is very similar to the previous one. There are some minor variations in the frame design. The rope channel is mounted lower on Version F, and so the force generated by the cam on the rope is more nearly centered. The area behind the cam leading to the rope channel was changed. Version C had a concavity behind the cam and a corresponding arch on the back side of the frame. Version E is flat behind the cam, and concave between two reinforcing ribs on the back side of the frame. "+GF+K9681" is cast in this concavity. The upper end of the cam channel is cast over in Version E, but in Version F it is open, and a stamped sheet metal cam housing is used instead. The handle area has been made smaller in depth. The details around the sling attachment hole are changed, with Version E being less bulky. The hole has been reduced to 24.5 by 10.4 mm.

The cam safety has been changed from aluminum to plastic, and is slightly smaller.

Comments

None of the changes mentioned seem to have a significant impact on any of the performance characteristics of the ascender. The only advantage Version F has over Version E is a slightly lighter weight.


Version G
(#1535)

Front Rear
Front Rear

Technical Details

I acquired my Jumar, Version G from Craig B. Clark in 2010.

Version G is 160 mm. tall, 74 mm. wide, 36 mm. thick, and weighs 203 g. The rope channel is 14 mm. wide. The cam radius increases from 41 to 59 mm. over an angle of 41°, giving a 27° cam angle. The tooth pattern is (4.5)^5(4.3)^4.

The only difference between Versions F and E is the color of the paint, and that "+GF+K9684" (not "+GF+K9681") is cast in the concavity on the rear of the left ascender.

Comments

This is the only Jumar I've seen with dark blue paint. Examining the finish, how it extends under the cam rivet and the sticker inside the shell, and the edges of the scratches penetrating to bare metal convinces me that the dark blue finish is original. On the other hand, the red in the rear behind the cam area was probably added by a previous owner. The edges of the red are not straight, and there are red paint smudges in other places on these ascenders.


Version H
(#118)

Front Rear
Front Rear

Technical Details

I acquired my Jumar, Version H from Theresa Williams and Maury Benamy in 1995.

This version is 159 mm. tall, 76 mm. wide, 32 mm. thick, and weighs 213 g. The rope channel is 14 mm. wide. The cam radius increases from 42 to 60 mm. over an angle of 41°, giving a 27° cam angle. The tooth pattern is (4.5)^3(4.3)^3. It has a spring-wire clip at the base. The safety has a countersink head wood screw added to serve as cam hold-open catch (added by a previous owner).

The initials "KK" are stamped into the frame.

Comments

This Jumar puzzled me for about 20 twenty years. It is essentially the same as Version F, even down to the "+GF+K9681" cast into the frame, but it is painted yellow. The paint is peeling off, but inside the frame there is a remnant of the original Jumar label over the paint, and the paint also runs under the cam rivet, so it appears that the paint was original. On the other hand, the cam looks unused while the rest of the ascender looks abused, so this may be a replacement cam, and a replacement sticker could have been added later. A touch of red paint on the pivot cover suggests a later repainting as well.

Bernard Sebille's Jumar Bernard Sebille's JumarI included this ascender because of the spring-wire clip at the bottom. It is well-made, and for a long time I wondered if it was original or was added by a previous owner. I suspected the latter, but on Halloween in 2015, Bernard Sebille sent me a note saying that it was original. He has one as well, and included the photos of his that I included here. Thank you, Bernard!

I think the clip is a bad idea, because it implies that you can tie in to this type of jumar by tying around the frame instead of using the square hole at the base the way it was designed. There have been several reports of ascender failure resulting from this mistake (Davison, Don Jr., Hits and Near Misses, N.S.S. News, v 34, #5, May, 1976, p. 80; Davison, Don Jr., Hits and Near Misses, N.S.S. News, v 35, #4, April, 1977, p. 73). I believe the clip was intended to guide the sling to the beefier side of the lower frame, and the wear marks on this side of the frame support this interpretation.