When loads get too big for forklifts and too precise for rough handling, teams turn to overhead cranes. This long-form walkthrough takes you behind the scenes of a mega-project crane install. We’ll cover structural checks, safety, and QA/QC—with the same checklists pro installers use.
Overhead Crane, Defined
An overhead crane rides on parallel runways anchored to a building frame, carrying a trolley-mounted hoist for precise, vertical picks. The system delivers three axes of motion: long-travel along the runway.
They’re the backbone of heavy shops and assembly lines, from beam handling to turbine assembly.
Why they matter:
Safe handling of very heavy, unwieldy loads.
Less manual handling, fewer delays.
Repeatable, precise positioning that reduces damage.
Support for pipelines, structural steel, and big machinery installs.
Scope at a Glance
Runways & rails: runway girders with crane rail and clips.
End trucks: motorized gearboxes for long-travel.
Bridge girder(s): single- or double-girder configuration.
Trolley & hoist: cross-travel carriage with lifting unit.
Electrics & controls: power supply, festoon or conductor bars.
Stops, bumpers & safety: end stops, buffers, travel limits.
Based on design loads and bay geometry, the crane might be a single-girder 10-ton unit or a massive double-girder 100-ton system. The installation flow stays similar, but the scale, lift plans, and checks grow with the tonnage.
Before the First Bolt
Good installs start on trimble viewpoint paper. Key steps:
Drawings & submittals: Freeze the GA and verify reactions with the structural team.
Permits/JSAs: Permit-to-work, hot work, working at height, rigging plans.
Runway verification: Survey columns and runway beams for straightness, elevation, and span.
Power readiness: Confirm conductor bars or festoon supports, cable trays, and isolation points.
Staging & laydown: Lay out slings, shackles, spreader bars, and chokers per rigging plan.
People & roles: Appoint a lift director, rigger, signaler, and electrical lead.
Millimeters at the runway become centimeters at full span. Measure twice, lift once.
Alignment That Saves Your Wheels
Runway alignment is the foundation. Targets and checks:
Straightness & elevation: Laser or total station to set rail height.
Gauge (span) & squareness: Use feeler gauges on splice bars, torque rail clips.
End stops & buffers: Verify clearances for bumpers at both ends.
Conductor system: Keep dropper spacing uniform; ensure collector shoe reach.
Log final numbers on the ITP sheet. Correct now or pay later in wheel wear and motor overloads.
Girder Erection & End Trucks
Rigging plan: Choose spreader bars to keep slings clear of electricals. Taglines for swing control.
Sequence:
Install end trucks at staging height to simplify bridge pick.
For double-girder cranes, lift both girders with a matched raise.
Land the bridge on the end trucks and pin/bolt per GA.
Verify camber and bridge square.
Before anyone celebrates, bump-test long-travel motors with temporary power (under permit): ensure correct rotation and brake release. Re-apply LOTO once checks pass.
Hoist & Trolley
Trolley installation: Hoist/trolley arrives pre-assembled or as modules.
Hoist reeving: Lubricate wire rope; verify dead-end terminations.
Limits & load devices: Check overload/SLI and emergency stop.
Cross-travel adjustment: Verify end stops and bumpers.
Pendant/remote: Install pendant festoon or pair radio receiver; function-test deadman and two-step speed controls.
Grinding noises mean something’s off—stop and inspect. Fix the mechanics first.
Power with Discipline
Power supply: Conductor bars with collectors or a festoon system.
Drive setup: Program VFDs for soft starts, decel ramps, and brake timing.
Interlocks & safety: E-stops, limit switches, anti-collision (if multiple cranes), horn, beacon.
Cable management: Keep loops short, add drip loops where needed.
Commissioning crews love clean labeling and clear folders. Photos of terminations help later troubleshooting.
Trust but Verify
Inspection Test Plan (ITP): Third-party witness for critical steps.
Torque logs: Re-check after 24 hours if required.
Level & gauge reports: Note any corrective shims.
Motor rotation & phasing: Document bump tests.
Functional tests: Jog commands, inching speeds, limits, overloads, pendant/remote range.
A tidy databook speeds client acceptance.
Ready for Work
Static load test: Hold at mid-span and near end stops; monitor deflection and brake performance.
Dynamic load test: Travel long-run, cross-travel, and hoist at rated speed with test load.
Operational checks: Emergency stop shuts down all motions.
Training & handover: Maintenance intervals for rope, brakes, and gearboxes.
When the logbook is clean, the crane is officially in service.
Everyday Heavy Lifting
Construction & steel erection: placing beams, trusses, and precast.
Oil & gas & power: moving heavy pumps, skids, and pipe spools.
Steel mills & foundries: hot metal handling (with the right duty class).
Warehousing & logistics: bulk material moves with minimal floor traffic.
Once teams learn the motions, cycle times drop and safety improves.
Safety & Engineering Considerations
Rigging discipline: dedicated signaler and stop-work authority.
Lockout/Tagout: clear isolation points for electrical work.
Fall protection & edges: approved anchor points, guardrails on platforms, toe boards.
Runway integrity: no cracked welds, correct bolt grades, proper grout.
Duty class selection: overspec when uncertainty exists.
A perfect lift is the one nobody notices because nothing went wrong.
Keep It Rolling
Crab angle/drift: verify end-truck wheel diameters and gearbox mounts.
Hot gearboxes: adjust brake air gap and reduce VFD decel.
Rope drum spooling: dress rope and reset lower limit.
Pendant lag or dropout: antenna placement for radio; inspect festoon collectors.
Wheel wear & rail pitting: lubrication and alignment issues.
A 10-minute weekly check saves days of downtime later.
Quick Answers
Overhead vs. gantry? Bridge cranes ride fixed runways; gantries walk on the floor.
Single vs. double girder? Span and duty class usually decide.
How long does install take? Scope, bay readiness, and tonnage rule the schedule.
What’s the duty class? FEM/ISO or CMAA classes define cycles and service—don’t guess; size it right.
What You’ll Take Away
Students and pros alike get a front-row seat to precision rigging, structural alignment, and commissioning. You’ll gain a checklist mindset that keeps cranes safe and productive.
Want ready-to-use checklists for runway surveys, torque logs, and load-test plans?
Download your pro bundle and cut hours from setup while boosting safety and QA/QC. Save it to your site tablet for quick reference.
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