Block

{
  "id": "MLC-T-OAG-000380",
  "term": "Block",
  "field": "Oil and gas",
  "definition": "The set of pulleys, or sheaves, that hangs from the top of the derrick (the crown block) or moves up and down the derrick (the traveling block). The drilling line is reeved through the sheaves of the crown and traveling blocks to create a mechanical advantage system for hoisting and lowering heavy loads like the drill string. The number of lines strung between the blocks determines the system's load capacity.",
  "subject": "Drilling",
  "url": "https://mlchart.com/terminology/oil-and-gas/block/"
}