MCS RIGGING REFERENCE SHEET
Components:
- Hardware (carabiners, rescue 8s, quick links, swivels, shackles, pulleys, etc)
- Suspension (round slings/span sets, tubular webbing, rope, hollow blocks, etc)
- Apparatus (silks, rope, sling, lyra, trapeze, etc)
Rating for all components of rigging:
· Preferred to be 22kN (4,900 lbs) or higher
· Rationale: 150# aerial test subject able to generate ~850# of force during a slack drop on silks measured with tension dynamometer. Round up to 1,000 lbs with a safety factor of x5 or higher = 5000lbs, or ~22kN.
Hardware Considerations:
· MCS hardware is primarily steel
· Best practice is to match steel with steel or aluminum with aluminum at contact points
· Obtain hardware from reputable sources
· Hardware must be used as intended
· Avoid triloading carabiners
· Screw-gate carabiners should be oriented so screw gate is closed and screws down prior to flight
· Carabiners should not be cross-loaded during flight
· Shackles and quick links should be moused appropriately
Suspension Considerations:
· Tying a knot in rope or webbing will reduce its rating by up to 50%; tying a knot in a span set is not allowed per the manufacturer’s documentation
· Choking a rope or webbing may reduce its rating by up to 50% (unless otherwise rated/indicated); choking a span set reduces its rating by approximately 21% (8,400 to 6,700)
· Basketing rope, span sets, or webbing will double its rating
· Water knot in webbing decreases the strength of the webbing by 50%. However, tying it into a loop means each half is carrying 50% of the load
Apparatus Considerations:
· Consult instructors for specific recommendations/sourcing
· Contact MCS aerial representative for approval of any new piece of equipment prior to use at MCS. Include sources/known ratings. Email is OK for standard equipment; face-to-face meeting is preferred for invented/novel apparatus
Inspection Overview:
· MCS inspects in-house rigging every six months with help from volunteers; no prior training needed
· Annual inspections of personal equipment, including personal hardware/suspension used at MCS, is required and must be recorded on an electronic log that can be provided upon request
· Sample Electronic Log for Apparatus, Sample Electronic Log for Hardware
· Brief visual inspection of ropes/carabiners/swivels/apparatus for integrity and orientation is advised every time you rig
Hardware Inspection:
· Inspect all contacts: greater than 10% wear at contact vs non-contact via caliper measurement=Retire/replace
· Swivels: evaluate for grinding/catching/uneven spin, should be smooth
· Carabiners: evaluate gate hinge and locking or screw-gate mechanism for grinding/catching/tracking, should be smooth
Suspension Inspection:
· Look for frays, especially at contacts with beams/hardware and pinrails tie-off area
· If you locate a fray/wear point, look for evidence of what may have caused it; make adjustments if appropriate
· Adjust span set or webbing contacts to distribute wear with each inspection
· Exposed inner contents or greater than 10% wear=Retire/replace
Apparatus Inspection:
Silks/sling
· De-rig from hardware/suspension materials, spread out on the ground and look for holes, runs, burns, frays
· Holes smaller than size of a quarter=May sew up and nail polish the edges
· Holes bigger than size of a quarter=Cut out and re-rig or retire
· Re-rig silks/sling at least once/year. Check technique with trusted source as needed
Rope/cloud swing
· Visual inspection of rope, look for frays/exposed content
· Inspect thimble and stitching for integrity/signs of wear
· If inner contents exposed on load-bearing portion=Retire/redress/replace
Trapeze
· Visually inspect rope-to-bar contacts at elbows; look for frays or separation
· Inspect bar for cracks, deformity, deep scratches which may impair integrity
· Inspect thimble and stitching or knots for integrity/signs of wear
· Trapeze with knots: untie to inspect and retie at least once/year. Check technique with trusted source as needed
Lyra
· Inspect all welds prior to/between taping, look for cracks, rust, separation, sharp areas
· Inspect metal tabs or contacts for signs of wear. If wear > 10%, retire
· Watch for any deformation or deviation from original shape
Other
· Follow best practice guidelines/consult instructor
MCS Truss Engineer Approvals:
· Static working load of 12,000 lbs distributed as 3,000 lbs on each of the 4 beams (A, B, C, D)
· 6 simultaneous drops of 1,000 lbs on 6 pulleys (double the roof force) spread over the grid
· May run circles or swing out to 45 degrees from any point
