S/V Constance, Alberg 30 #262 -- Mast Climbing

Method

• Harness on body.
• HMS locker (Petzl Attache) connecting harness belay loop to VT Prusik set as an autoblock around mildly tensioned jib halyard. (safety connection. should automatically slide up the halyard when ascending and lock immediately when weighted.)
• HMS locker (Petzl Attache) connecting harness belay loop to the ear of an ATC Guide, in guide-mode on both main and jib halyards. ATC Guide used as a progress capture device. (While ascending only).
• 30cm Dynex sling girth hitched to harness belay loop connected to locking HMS locker (Petzl Attache) set in belay mode for descending on both main and jib halyards.
• Petzl Ascension attached to main topping lift with 120cm Dynex sling for a foot-loop.
• Check:
• Verify ATC Guide in guide mode connected to belay loop of harness via HMS locker (Petzl Attache).
• Verify ATC Guide connected to belay loop of harness via 30cm Dynex sling which is connected to HMS locker (Petzl Attache) on ATC Guide in High Friction Mode.
• Sit in harness supported by autoblock on jib halyard connected to belay loop of harness via HMS locker (Petzl Attache). (Is there room for the autoblock in guide mode?)
• Sit in harness support by ATC Guide, in guide-mode on both main and jib halyards.
• Ascending:
• Sit in harness.
• Slide Ascension as high as comfortable.
• Stand in foot-loop. While standing autoblock should slide along jib halyard.
• Take in slack of the main halyard through the ATC Guide, in guide-mode, using ATC as an ascender.
• Sit in harness supported by both autoblock and ATC Guide, after having ascended the length of a leg moving from folded to standing.
• Repeat
• Descending:
• Stand on foot-loop OR Transfer weight onto the autoblock (possible? is there room for the autoblock when the ATC Guide is connected to the harness belay loop in guide mode?)
• Disconnect HMS locker connecting harness belay loop to the ear of an ATC Guide, in guide-mode. ATC Guide will be used in extended rappel configuration on both main and jib halyards.
• Transfer weight to ATC Guide and lock off (as shown at timestamp 17:20).
• Remove and stow Ascension and foot-loop.
• Rappel down main halyard using ATC Guide with autoblock as a safety.
• Once on the deck, remove all gear.

References

• Using a VT Prusik above an ATC Guide on rappel and to climb: see two and a half minutes starting at timestamp 50:00 in video
• Using 3:1 mechanical advantage with an ATC Guide and an ascender to ascend a rope.
• Shockload due to 60cm fall caught on a Dyneema sling: ~4-1/2kN. 12:05
• Tying an "air clove hitch" video @ 1:47)
• Tying an "one-handed clove hitch" video @ 2:36)
• Extended rappel technique from Alpine Savvy and video (4:38) from SIET (School for International Expedition Training).
• ATC Guide as an ascender technique.
• VT Prusik uses.
• Prusik, Auto Blocks, and Klemheist href="https://www.youtube.com/watch?v=0fdOn2futNc">Break Tests on 10.5mm dynamic rope using Sterling Hollow Block and 4mm paracord, 5mm and 7mm accessory cord. Auto Block numbers are signifcantly less than either Prusik or Klemheist.
• How to lock off a tubular rappel device, such as the Black Diamond ATC Guide, at timestamp 17:20
• Rappel
• Rope ascending with a Grigri and belay device article 2023-04-06
• Using a Grigri to ascend fixed ropes article 2019-02-07
• Strength
  • Girth hitch 8mm Dyneema sling on hanger: 12-13kN (See this video from HowNOT2 for each result)
  • Girth hitch 8mm Dyneema sling on round stock carabiner: 17-20kN
  • Girth hitch two 8mm Dyneema slings together: 11kN
  • Girth hitch 8mm Dyneema sling master point: 27-32kN
  • Girth hitch 18mm nylon sling on hanger: 8-9kN
  • Girth hitch 18mm nylon sling on round stock carabiner: 19-20kN
  • Girth hitch 18mm nylon slings together: 11-18kN
  • Girth hitch 18mm nylon sling master point: 32-33kN
• Accessory Cord strength