Show GUARDING AGAINST BURSTING BULL WI WHEELS bull wheels run at excessive speeds sometimes blosl b up lip says the united states bureau of mines in a recen aly issued bulletin dealing dealina with safety at oil derricks steel as well as wooden bull wheels burst when the speed ot ro tation exceeds the safe limit just what the safe speed 5 is depends generally on factors over which the tool dresser 01 workman on the derrick floor has no control A good rule to follow when lowering tools into the hole n g is to keep the maximum speed of rotation of the bull wheels wn such that slight pressure on the brake lever will E sla lacket j d descent of the tools faulty brakes loose brake bands an brake bands insecurely fastened to the sills underneath under neat n bull the floor are contributing causes of the blowing up of 01 alli wheels to reduce the possibilities of material damage bamat ae of human injury the braking equipment should be fre inspected and all faulty parts repaired promptly |