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Petzl Stop

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

Overview


Version A
(#435)

Front View Rear View Side View
Front View Rear View Side View
 
Front View: Open for Rigging Rear View: Open for Rigging
Front View: Open for Rigging Rear View: Open for Rigging

Technical Details

I acquired this descender from Repetto Sport in Genova, Italy in 1982.

My Version A is 225 mm. tall, 61 mm. wide, 33 mm. thick, and weighs 289 g.

The side plates are black anodized aluminum similar to those in the single rope Petzl Version B. This bobbin also has a similar quick attach feature.

The lower bollard is part of an autostop assembly. The upper surface of the bollard is milled flat and a J-shaped piece of 3 mm. steel is inset and screwed to the bollard. This protrudes at the 10 o'clock position and acts as a cam much like the cylinder attached to the Diablo. A aluminum handle is riveted to the fixed side plate side of the lower bollard. The handle portion is bent into a U to increase thickness for comfort. The lower bollard and handle assembly rotate on a shoulder nut on the lower bolt. A concealed spring tries to keep the handle in the disengaged position, but is weak enough to function only during storage. Friction from the main rope's passage tends to turn the lower bollard and force the toothed cylinder towards the upper bollard, thus locking the rope and ideally arresting the descent. The rappeller uses the handle to keep the autostop feature disengaged. Alternately, a hole in the handle plate opposite the handle itself allows one to clip a carabiner in, thus disabling the autostop feature by preventing rotation of the lower bollard assembly. A small cutout in the fixed side plate provides clearance for this carabiner.

The upper bollard is cut away on its lower side to provide a flat surface to act as an anvil for the cam action of the autostop feature. A rounded 10 mm. steel cylinder is pressed into a hole in the lower surface of this bollard, and acts as a wear resisting bar.

The pivoting side plate is stamped with an icon illustrating how the descender is threaded, but anyone who needs this assistance shouldn't be using a bobbin anyhow. It is also stamped "STOP," "BREVETE," "FRANCE_Etranger," "PETZL" inside an ellipse, "MAXI 1500 KG," and "FRANCE." The bolt heads are marked "A2" twice.

Comments

This bobbin was one of the descenders in my normal caving set, so I have used it extensively in a wide variety of conditions. Unlike most autostop bobbins, the Petzl design works well, perhaps due to the flat cutout on the bottom of the upper bollard. I prefer this bobbin over any other autostop descender (bobbin or other) in my collection. Despite this, one must realize that the availability of an autostop feature may encourage one to rely on it. Since the required action in an emergency situation is letting go of the descender, the autostop feature should never be relied on. See my 1995 internet post on rappel safeties for more information.

The handle spring is a nice idea. Its only function is to keep the handle from flopping around inside one's pack. It is far to weak to have any adverse effect while on rappel. Petzl does not use a bronze bollard bushing like in the Diablo, and I have never missed having one. All in all, I feel that this device is very well made, and aside from its inability to function on doubled ropes, it has served me very well.


Version B
(#436)

Front View Rear View Side View
Front View Rear View Side View
 
Front View: Open for Rigging Rear View: Open for Rigging
Front View: Open for Rigging Rear View: Open for Rigging

Technical Details

I acquired this descender from Caves Unlimited in 1984.

My Version B is 226 mm. tall, 64 mm. wide, 32 mm. thick, and weighs 302 g.

It differs from Stop Version A in the pivoting side plates and bolts only. The pivoting side plate has been made about 6 mm. wider in the area of the upper bollard nut clearance notch and approximately 8 mm. wider in the quick-attachment area. Both side plates are blue anodized.

The pivoting side plate markings are identical to Version A's markings except for the omission of "MAXI 1500KG." The bolts are marked with "A2" and an "L" inside a diamond.

Comments

Performance is identical to Version A's. The beefed up side plate may increase strength, but I doubt that anything is wrong with the strength of Version A, so I consider the extra weight superfluous. The use of a different lot of bolts is unimportant. I almost never use this bobbin since I see no advantage over Version A.

People who are into strength ratings of vertical gear should read the descriptions of the side plate markings for Versions  A and , and C. I am not sure if Version B is really any weaker than Versions  A. If it is, then the change was for the worse. On the other hand, if the older Stops are not stronger, then why did Petzl claim they were? If there is a legitimate explanation for the differences, I would like to hear it.


Version C
(#1324)

Front View Rear View Side View
Front View Rear View Side View
 
Front View: Open for Rigging Rear View: Open for Rigging
Front View: Open for Rigging Rear View: Open for Rigging

Technical Details

I acquired my Petzl Stop, Version C from Geoffrey Storey in 2012.

My Petzl Stop, Version C is 231 mm. tall, 63 mm. wide, 32 mm. thick, and weighs 297 g.

This bobbin functions on the same principles as the previous Stop models, so I'll keep the description brief. The major differences between Versions B and C is that the handle on Version C has a loose fitting red plastic cover.

The markings on Version C are the same as those on Version B.

Comments

The red slip-on plastic handle looks pretty, but serves no useful purpose except perhaps in extreme cold. It tends to get chewed up after a few exposures to the harsh cave environment. I never missed not having one on Version A.


Version D
(#2420)

Front View Rear View Side View
Front View Rear View Side View
 
Front View: Open for Rigging Rear View: Open for Rigging
Front View: Open for Rigging Rear View: Open for Rigging

Technical Details

I acquired my Petzl Stop, Version D in 2017 as part of Bob Thrun's collection.

My Petzl Stop, Version D is 229 mm. tall, 62 mm. wide, 32 mm. thick, and weighs 309 g.

The major differences between Versions D and C is the shape of the steel insert on the lower bollard. This piece has an extension that engages a notch cut in the side of the fixed side plate, limiting how far the lower bollard assembly can move toward the "stop" position.

The pivoting side plate is stamped with an icon illustrating how the descender is threaded, but anyone who needs this assistance shouldn't be using a bobbin anyhow. It is also stamped "STOP," "BREVETE," "FRANCE_Etranger," "PETZL" inside an ellipse, and "FRANCE." The bolt heads are marked with "A2" and an "L" inside a diamond.

Comments

The stop limit provided by the new insert does not accomplish anything in the field, since the rope limits the bollard rotation, as it should. I suspect that it has benefits when overloading the bobbin on a testing machine. Personally, I'd prefer not to have it, and without it, Petzl could eliminate the sharp notch in the rear side plate.


Version E
(#437)

Front View Rear View Side View
Front View Rear View Side View
 
Front View: Open for Rigging Rear View: Open for Rigging
Front View: Open for Rigging Rear View: Open for Rigging

Technical Details

I acquired this descender from J. E. Weinel Inc. around 1987.

My Version E is 240 mm. tall, 63 mm. wide, 32 mm. thick, and weighs 327 g.

This bobbin functions on the same principles as the previous Stop models, so I'll keep the description brief. The major differences between Versions C and D are as follows:

  1. Version E incorporates a third auxiliary rod similar Petzl Simple, Version G.
  2. The lower bollard is now a skeletonized casting, and the cam is an integral part of the casting.
  3. The handle is no longer screwed to the lower bollard. It now fits into a recess in the casting.
  4. The semi-tubular rivet holding the attachment point guard on now has the smooth head on the inside next to the rope.

The markings on Version E are the same as those on Version B and C.

Comments

There are a number of things about this bobbin which I like less than in the previous versions. Mostly I dislike the lower bollard. The skeletonized casting may be lighter, but the shape does not have nearly the wearing capacity that the machined bollards had. There is no internal bracing in the casting, and the shape is undoubtedly weaker than the machined bollards. For these reasons, the switch to using steel instead of aluminum appears to have been necessary, but steel is not as good a thermal conductor as aluminum. When rappelling too fast, the lower bollard can easily overheat. The handle attachment does not appear to be as secure as the riveted ones. The auxiliary bollard has all the disadvantages as in the case of the single rope standard bobbin Version E. All in all, I think this model is a significant step backwards for Petzl.

Petzl Stop descenders are protected by U.S. Patent #5,850,893, which contains drawings showing a version with the frame of Version B and the bollards of Version E.


Version F
(#438)

Front View Rear View Side View
Front View Rear View Side View
 
Front View: Open for Rigging Rear View: Open for Rigging
Front View: Open for Rigging Rear View: Open for Rigging

Technical Details

I acquired this descender from Bob & Bob in 1991.

My Version F is 225 mm. tall, 62 mm. wide, 32 mm. thick, and weighs 322 g.

Petzl added some internal ribs to the lower bollard, and folded the sides of the fixed side plate to make it more resistant to bending.

The markings on the pivoting side plate of Version F are the same as those on Version B. The fixed plate is also stamped with an illustration of how to rig the bobbin. This diagram is reversed from the one on the pivoting side plate since one is looking from the other side. The bollard bolt heads are marked with "IN-IV" and "A2-70."

Comments

I still prefer Version A.


Version G
(#541)

Front View Rear View Side View
Front View Rear View Side View
 
Front View: Open for Rigging Rear View: Open for Rigging
Front View: Open for Rigging Rear View: Open for Rigging

Technical Details

I acquired this descender from TSA at the International Congress of Speleology in 1997.

My Version G is 223 mm. tall, 68 mm. wide, 32 mm. thick, and weighs 325 g.

Petzl finally replaced the stamped gate catch with a plastic one. It pivots on a steel rivet, and a spring set in a deep slot closes the gate. With the gate closed, the opening is only 15.8 mm high. The gate has a widened flat spot on the outside that is clearly designed to provide a convenient place for one's thumb to act to open the gate.

The pivoting side plate is stamped with the "Reading is Dangerous" icon, "CE0197," "STOP," "PATENTED," "ROPES 9≤Ø≤12," a circle within a circle icon, an illustration of how to rig the bobbin, and the Petzl logo. The fixed plate is also stamped with "97133A" and an illustration of how to rig the bobbin. This diagram is reversed from the one on the pivoting side plate since one is looking from the other side. The bollard bolt heads are marked with "PETZL" and "A2-80." The Petzl logo is molded into the gate.

Comments

This gate design greatly reduces the risk of having the seat carabiner force the gate open. It also eliminates the corrosion problem that I've had with the metal gates on some of my other Petzl bobbins. Overall, I think the new gate may be an improvement, if it holds up under the abuses inherent in serious caving, but the wire gate on the Russian Stop Bobbin, Version B is a worthy alternative.

There is enough reading material stamped on the pivoting side plate to stave off boredom on long rappels, but please, be safe and pay attention to the rappel.