What is the difference between derrick and mast

After the Rigger courses, a student attains a rigger certification. A tandem lift involving the simultaneous use of more than two cranes, hoists or other pieces of powered lifting equipment. Tandem lifts can be very useful, and they are often used to place structural beams for bridges, move large loads, and lift long components from horizontal to vertical positions.

However, tandem lifts have the potential to become very dangerous if not handled properly. Critical lift means a lift that 1 exceeds 75 percent of the rated capacity of the crane or derrick, or 2 requires the use of more than one crane or derrick. Lifting operations need to be properly planned by a competent person who has both practical and theoretical knowledge, and who has experience of planning lifts.

The lifting plan needs to consider the risks involved, the equipment needed, the procedures for the lift, and who has to do what. All work involving telehandlers must be planned by a competent person, appropriately supervised and carried out in a safe manner. Where a telehandler is to be used as a crane for lifting suspended loads, additional planning is required by a competent person.

It may or may not be guyed. A derrick is normally used on offshore rigs and they can be divided into two categories; stationary derricks and dynamic derricks. A stationary derrick is used on offshore fixed structures and jacked up rigs, whereas a dynamic derrick is used on a floating rig, which is subjected to marine stress.

Your email address will not be published. This site uses Akismet to reduce spam. Learn how your comment data is processed. What is Kelly Rig? By DrillingFormulas. Offshore BrownField Construction Projects. Racking Board Assemblies. Derrick Assembly. Derrick CMC Removal. Rope Access Services. Derrick Upgrade Projects. Platform Decommissioning. PRV Inspection.