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Singing Rock

DSD 30+25 DSD plus
DSD 30+25 DSD plus

Overview


DSD 30+25
(#1233)

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 Singing Rock DSD 30+25 from Inner Mountain Outfitters at the 2009 UIS/NSS Convention.

The Singing Rock DSD 30+25 is 191 mm. tall, 81 mm. wide, and 28 mm. thick, and weighs 347 g.

The Singing Rock DSD 30+25 consists of a control handle/upper bollard assembly and a lower bollard casting, each pivoting between two 3 mm. stamped aluminum side plates. The side plates have raised portions in their lower half to provide some rigidity. Each plate has a 15.7 by 19.2 mm. pear-shaped hole at the base for attaching to one's harness. The two plates are compressed toward each other at the lower side of the hole. The control handle pivots from a rivet near the top of the side plates. The upper bollard is a 32 mm. aluminum turning mounted on the same rivet as the control handle. The pivoting bollard assembly is a steel casting with integral lower bollard, upper bollard and guide pin. It mounts midway on the frame with a rivet that passes through the approximate center of the lower bollard.

One side plate is printed with an up-pointing arrow, "CE0123," "singing rock," "DSD 30+25," "0909-017," a figure showing the normal rigging, "30-150kg," "max 200m," "EN 341 CLASS A ROPE * 11mm" and "* 10≤Ø≤12 mm" (where the * represents a dot inside a circle). The other plate is stamped with a page icon with an explanation mark beside it, "PROPER TRAINING IS ESSENTIAL BEFORE USE," another figure showing the normal rigging (a mirror of the other side - one is looking at the reverse), and "PATENTED." The handle has the Anthron logo forged ito it.

Comments

The following descenders are all variations of the same basic design:

Image Descender Pivoting Assembly Allowed Rope
Antec Double Stop Antec Double Stop Bare 9-12 mm.
Anthron DSD-25 Anthron DSD-25 Plated 9-12 mm.
Anthron DSD-25 Anthron DSD-30 Bare 11 mm.
Anthron DSD 30+25 Anthron DSD 30+25 Plated

11 mm. (EN341 Class A)

10-12mm. (EN 12841 Type C) 

Magideal I-Block Magideal I-Block

10-12mm.

Singing Rock DSD 30+25 Singing Rock DSD 30+25

11 mm. (EN341 Class A)

10-12mm. (EN 12841 Type C) 

Skylotec Mark 1 Skylotec Mark 1

With the exception of the MagiDeal, which I obtained from China, these were all made in Europe by the same company, operating under different names and owners. I could not find any significant dimensional differences between the European versions in the table, and certainly none that justify different rope diameter limits. The Singing Rock DSD Plus is a later modification that has some significant changes but what is the difference between the, say, the DSD-25, DSD-30, and DSD 30+25? In despair, after seeing a related comment on one of their YouTube videos, I asked the following question:

A historical question: What is the difference between the DSD 25, DSD 30, and DSD 25+30? I'm holding all three and digital calipers as I write this, and there do not seem to be any significant dimensional differences between those three models. The DSD plus is obviously different. What, if anything, am I missing? Thanks in advance!?

Anthron replied as follows:

The differences between them are about European norms development. At the time DSD-25 came to market there wasn't any norm for descenders yet. After EN 341 was published it was decided to rename the device to DSD-30. It was not a very intuitive move, but after the publication of EN 12841 and DSD demonstrating conformity with it, the same descender became DSD 30+25 (now conforming to both EN 341 and EN 12841 C). In 2011 an update to the norm EN 341 was issued. This was much stricter in terms of requirements and an update to the device was necessary. Thus the DSD plus and DSD pro were developed. The DSD 30+25 currently keeps conformity with EN 12841 C (with a valid certificate) but is obsolete according to EN 341:2011.?

These descenders are designed for single ropes. The bollards are on a pivoting frame. When the handle is released, the rope tension pulls the bollards inward, squeezing the rope between the upper bollard and a third bollard (not visible) mounted on the handle pivot. This stops the rappeller, although it doesn't work unless there is tension on the rope below the rappeller (i.e., don't count on it working at the end of a drop). Squeezing the handle forces the bollard assembly to rotate outward, allowing one to descend. Squeezing the handle further squeezes the rope between the handle and an auxiliary bar on the bollard assembly, again causing the rappeller to stop. The entire system relies on squeezing the handle enough, but not too much (position 2), so that if the rappeller either lets go (position 1) or panics and over-squeezes (position 3), they will stop. I find these types of systems take getting used to, and in my mind are somewhat of a nuisance, but that is a personal preference that some others don't share. For a variety of reasons, I prefer not to rely on auto-stop features in any descender.

Note that the tail end of the rope is trapped instead of hanging free from the upper bollard like it does on many other bobbins. This eliminates the need to add a second maillon or rapide as shown on the Bobbins: General Comments page.


DSD plus
(#1460)

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

Technical Details

I acquired my Singing Rock DSD Plus from Amazon.com in 2015.

My Singing Rock DSD Plus is 198 mm. tall, 86 mm. wide, 33 mm. thick, and weighs 430 g. The following description is modified from the DSD 30+25 description, with differences shown in black

The Singing Rock DSD plus consists of a control handle/upper bollard assembly and a lower bollard casting, each pivoting between two 3 mm. stamped aluminum side plates. The side plates have raised portions in their lower half to provide some rigidity. These are shaped differently than those on the DSD 30+25. Each plate has a 15.3 by 20.1 mm. pear-shaped hole at the base for attaching to one's harness. The two plates are compressed toward each other at the lower side of the hole. The control handle pivots from a rivet near the top of the side plates. There is a stainless steel wear block screwed to the underside of the handle where it contacts the rope. The upper bollard is a stainless steel block mounted on the same rivet as the control handle. The pivoting bollard assembly is a steel casting with integral lower bollard, upper bollard and guide arm. It mounts midway on the frame with a rivet that passes through the approximate center of the lower bollard.

One side plate is printed with an up-pointing arrow, "singing rock," "DSD plus," a figure showing the normal rigging, "CE0123," and "0514-002." The other plate is printed with an up-pointing arrow, "singing rock," another figure showing the normal rigging (a mirror of the other side - one is looking at the reverse), "EN12841-C," a dot inside a circle, "9 mm, 130 kg," "10 - 12 mm., 200 kg" and a book-with-an-"i" icon. The lower bollard has a date indicator that shows that it was made in November 2013.

Comments

The EN 341 standard changed in 2011, requiring more demanding testing. The DSD plus was designed to pass the new version of the standard. The resulting Rock DSD plus is 24% heavier than the DSD 30+25. The lower bollard casting is more massive than the one on the DSD 30+25, and there were minor changes to the rope channel. Although I like the steel insert in the handle.