Rigging

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Rigging

• Unit 5 A
• Hoists cranes

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Industrial hoists cranes

• Overhead hoists
• under-slung cranes
• top-running cranes
• jib cranes

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Overhead manual chain hoists

• Hand chain turns a pocket wheel
• 1/2 to 60 ton capacity
• suspended trolley

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Overhead powered hoists

• Electric or pneumatic powered
• chain hoist or wire rope
• reeving (wire rope)-passing a rope over the
  sheaves , gains mechanical advantage
• single reeved-1 rope, block moves horizontally as
  the hook ??
• double reeved1 rope, both ends attached to drum,
  load stays centered as hook ??, can use smaller
  rope, drum sheaves

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Overhead hoists 2

• Parts- the number of rope lengths between the
  drum the hook
• More parts more mechanical advantage
• operation-generally a push button control pendant
  with ?? and an emergency stop button
• multi-speed control,
• brake system
• limit switch

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Jib cranes or hoists

• Can be wall mount or pedestal mount
• fixed, partial rotation or full rotation
• top braced, under-braced or cantilever
• rotation type have bearings

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Safety 1

• Only 1 operator per hoist
• only 1 boss per hoist EXCEPT for STOP!!
• Do not side pull a load, this is very
  dangerous-do vertical lifts only

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Overload limit devices

• Keep hook from going too far up
• prevent damage to unit when exceeding lift
  capacity
  
• are not a guarantee of safety

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Bridge Cranes

• A Bridge Crane system consists of three major
  components.
• the Bridge Crane, which traverses across the
  runway
• the hoist trolley, which traverses across the
  bridge and lifts up and down
• the runway, which is tied to the building
  structure.

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Website

• http//www.dearborncrane.com/pdf/bridge_cranes/Cra
  ne20Description.pdf

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Under-slung cranes

• Hoist is suspended from 1 or more bridge beams
  fitted with end trucks
• smaller lift capacity than top-running cranes
• used where ceiling space is limited

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Top running cranes

• Cranes are mounted on top of support beams, run
  on rails
• gantry cranes
• semi-gantry cranes or half gantry cranes
• operation-cab operated, pendant control, radio
  control
• the crane operator is not the rigger!!!!

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Top Running or Under Running?

• Top Running vs. Under Running is primarily
  determined by two factors
• Capacity - Although under running can be up to 25
  ton capacity, the practical limit is more like 15
  tons and the economic sweet spot is 1 to 7.5 ton
  range.

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Top Running or Under Running?

• Support Structure - Under running can be
  suspended directly from the overhead steel (for
  lighter cranes). Top running cranes will require
  a bracket off the building support steel (up to
  10 tons capacity) or independent columns for
  heavier capacities.

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Top Running or Under Running?

• The top running configuration is best used in
  cases where the end user has issues with
  headroom. The most space efficient configuration
  is the double girder, top running crane system.
  When headroom is not an issue a top or under
  running configuration can be used with either the
  double or single girder bridge crane.

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Inspection

• Inspect service periodically
• trained personnel
• as required by OSHA
• hooks, cable, drum, sheaves, contacts, gear
  boxes, limit switches, controls, brakes, lube

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Hand signals

• Communication between rigger crane operator
• very important
• only 1 rigger per job except for STOP