SRT, DRT, DdRT, DmRT, SRS, MRS, WTF?
Technical tree climbing revolves around two primary principles, using either a stationary or moving rope system, depending on the type of tie in.
(SRT) Single (sometimes called Stationary) Rope Technique has been associated with a stationary climbing line secured with a canopy or a basal (ground based) tie-in-point. The rope always remains fixed at the anchor point when the climber ascends or descends.
(DRT) Double Rope Technique and (DdRT) Doubled Rope Technique are often confused, but most of the time they are associated with a climbing line that goes up over a limb, and back down to a climber. If one is splitting hairs, the difference between double and doubled is how DRT refers to climbing on two ropes with separate anchor points, whereas DdRT refers to a single moving rope, doubled over a limb with the climber advancing on one side of the two legs. What could be more confusing?
DdRT climbers are attached to both sides of a single line, and when advancing either up or down using one side of the two legs, the rope moves as it passes over, or around, a limb and back to the climber. The climber controls both ends of the line, offering easy retrieval, while the rope is “doubled” over a limb, hence the name.
DRT is actually described as two separately anchored lines that create a single stationary line which a climber can ascend using a footlocking method on both lines, or climb with one of the two stationary legs, while using the other leg as a backup.
DdRT and DRT describe two distinctly different climbing methods, but a lot of educational material is incorrectly using the DRT acronym to describe DdRT. Moreover, everyone seems to miss the boat entirely when it comes to teaching any DRT methods, as if it’s some kind of ancient lost art. Perhaps DRT is a method used by rock climbers and by other at-height professionals, since it’s not as well suited for maneuvering in tree canopies as say SRT and DdRT.
DRT, DdRT and (DmRT) Doubled Moving Rope Technique, are all different. DmRT uses both legs of single climbing line that’s doubled over a limb with a dualcender, or a progress capture device for each leg, versus DRT where the climber is using two separately anchored lines and DdRT where the climber only advances on one side of the doubled line.
In the video below, Richard Mumford appears to inadvertently demonstrate the DmRT type of system using a Rock Exotica Dualcender. He then combines traditional DdRT and what we may now call DmRT into one inclusive DmRT acronym, which I believe is incorrect. What he may not realize is that he’s demonstrating two unique systems and not simple variations of DdRT. The DmRT method, as demonstrated near the end of the video, shows how a climber can advance up two lines together, creating an inch-worm like ascending effect and by using a right and left foot ascender with a dualcender device in an alternating, see-saw like way, the climber gains a 2:1 (MA) Mechanical Advantage. Using DmRT, a climber can also easily transition between a 2:1 MA and a 1:1 MA, based on whether the two legs are joined in a secured footlock, or kept separate with individual foot ascenders.
This is all very hypothetical. Safety, efficiency, impact on gear are highly speculative and questionable, but if you think about it, a DmRT system can be a very versatile system, easily able to transition into DRT, DdRT or an SRT system, depending on the how the legs of the doubled-moving line are managed.
In the product demonstration video below, it shows how a dualcender device can rely on the use of both legs of a doubled rope in a DmRT configuration. Rock Exotica’s Dualcender and the Petzl Shunt may pose unnecessary risks to a climber when used in this type of configuration if shock-loaded. Other risks may include and are not limited to causing localized or uneven wear spots on a line, hardware malfunction, etc.. Nonetheless, in a DdRT system, the climber only advances on one leg of the doubled rope compared to DmRT which uses both legs to advance a climber. This notable distinction warrants giving DmRT a different acronym than DdRT.
DmRT may eventually evolve into a popular tree climbing system, with a whole new assortment of climbing gear designed specifically for this purpose, including something like a possible dAkimbo, or a homemade dual-ascender using two hand ascenders duct taped together. For now the two most popular contenders are are clearly DdRT and SRT and any changes to these acronyms may not only effect the lingo used by tree climbers, but many others, including rock climbers, skyscraper window washers, pole workers, etc.
Another idea is to simply change DdRT to MRT and leave DRT and SRT unchanged. Because DRT & DdRT are inherently conflicted acronyms, NiceGuyDave @ Wesspur clarified the differences and proposed SRS and MRS, thereby eliminating or bypassing the use of the DRT and DdRT acronyms, in the traditional sense. This makes a lot of sense to many, but it may limit innovation when other variations in viable climbing methods are possible, as well.
As more attention is given to this issue, a clear path becomes more evident. There needs to be a consortium and agreement in order to achieve consensus, at least among the primary players, including major equipment dealers, the ISA and similar organizations.
When we combine the two concepts concerning the use of rope legs, further identified with the act of remaining stationary or not, it alleviates a lot of confusion and improves clarity in a uniform manner, as follows:
SSR = Single Stationary Rope Technique, versus: SRS & SRT
SMR = Single Moving Rope Technique, versus: MRS & DdRT
DSR = Double Stationary Rope Technique, versus: DRT
DMR = Double Moving Rope Technique, versus: DmRT
Replacing vaguely descriptive acronyms can address the methods more descriptively and provide a more solid and universally accepted definition. One might still confuse the difference between DRT is different than DdRT, but opinions vary, depending on who you ask, what educational videos you watch, etc. The fact remains, it all comes down to whether there are one, or more, stationary or moving ropes involved.
DRT represents the pending marriage of, or union of, two separately anchored lengths of rope. Once the two ropes merge as one moving rope doubled over a limb, two distinct sub-sets of climbing methods clearly emerge, known as DdRT and DmRT. Using the generic “DRT” acronym, as a representative of all three (two-legged) climbing methods, may be permissible in certain contexts, or among certain audiences, but without further clarification it remains vague and ambiguous.
In conclusion, uncertainty does exist when it comes to describing the existing acronyms and reassigning new acronyms. Most will probably continue to refer to SRT and DRT, or adapt to using SRS and MRS in general terms, but time will tell and at some point the tree climbing community will hopefully unite, adopt and agree on the use of more properly descriptive acronyms to describe the various climbing methods.
Happy climbing. Be Safe!