Weld Fails -- Derrick Collapses
Effective Date: 8/18/1975
 | Minerals Management Service Gulf of Mexico OCS Region |
Notice No. 028
August 18, 1975
OCS Operations Safety Alert
Weld Fails -- Derrick Collapses
The derrick on an offshore platform workover rig recently collapsed when the welds in the skid gave way.
The rig was fishing for 1" pipe with an overshot and hydraulic jars in the hole. The jars had been activated several times when on a subsequent pull the derrick collapsed. Approximately 10,500' of 1" pipe, in single lengths, was standing in the derrick. Some falling equipment struck one crewman, inflicting minor injuries. A diesel fuel supply tank overturned and caused minor pollution.
To prevent a recurrence of this accident, the operator has been advised by the contractor that the following procedures and modifications have been performed:
1. All welds have been x-rayed to insure weld quality.
2. Skid breakdown area has been moved further back along skid base to relieve stresses at the skid joint.
3. The drawworks has been installed directly over the breakdown area to stiffen the connection.
4. Bolts used to hold the skid section together have been replaced by pin connections.
[signed] D.W. Solanas
Oil and Gas Supervisor
Field Operations
Gulf of Mexico Area