First Incident: The rig was doing a wiper trip. While working through a tight spot, the Driller lost count of the singles. The top layer of drilling line on the drum passed through under the crown saver device toggle. The blocks collided with the crown bumper block shaking the derrick upon impact. Crown saver device had not been tested on this shift.
Second Incident: During a trip out to change the bit, someone was trying to talk with the driller causing him to be distracted and the blocks hit the crown. The tool joints had been miscounted and even though the crown saver device activated, it did not stop the blocks in time to prevent collision. It was determined the crown saver device was set too high and trip speed was excessive. It had been tested but not with the drilling line.
Third Incident: While pulling out of the hole, the driller miscounted the tool joints.