What happened: NM-PLD-ROT 8.5 TONGS FALL 2 FT. TO THE RIG FLOOR. While POOH, the ROT 8.5 tongs fell approximately two feet to the rig floor when the pin backed out of the bolt type shackle holding the tongs. At the time of the incident, the crew was

1
Shell EPW Wells HSE Learning Bulletin
Fountain Report No 106128 Location
EPW Wells Incident Date 10-01-06
What happened NM-PLD-ROT 8.5 TONGS FALL 2 FT. TO
THE RIG FLOOR. While POOH, the ROT 8.5 tongs fell
approximately two feet to the rig floor when the
pin backed out of the bolt type shackle holding
the tongs. At the time of the incident, the crew
was required to manually maneuver the tongs
because the hydraulic push arm had broken earlier
in the day. Operations were suspended and a PAUSE
was held to revise and review a JSA to remove the
push arm and address the change in job scope. The
hydraulic push arm was removed from service and a
replacement was ordered. A preliminary
investigation revealed that with the arm removed,
the cables and shackles are in contact with the
stabbing board. As the tongs were set back and
placed on the deck, the release of the tension
caused the cable to twist. It is possible that
the cotter key was either knocked out or sheared
off when the shackle pin came in contact with the
stabbing board. As the stored energy was released
from the line, there is the potential for the nut
to back off of the shackle pin allowing the pin
to work itself out.

• Learning points
• The weight of the tong assembly was 5600 lbs.
  When the tongs were lowered, the cable that
  supported the tongs twisted as the tension was
  released. As the tongs were pushed back and set
  down, the support shackles came in close
  proximity to the stabbing board. These potential
  hazards were not identified after the removal of
  the push arm.
• Visual inspections should identify areas where
  lines, slings and shackles used to support any
  equipment may contact any overhead equipment.
• Due to the potential failures of internal seals
  and components of the push arm, scheduled PMs or
  change out should be performed

Shackles in contact with the stabbing board