Overhead cranes—often called bridge cranes—are the quiet workhorses that keep heavy industry moving. This long-form walkthrough takes you behind the scenes of a mega-project crane install. You’ll see final load testing and handover—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.
You’ll find them in fabrication bays, steel plants, power stations, oil & gas shops, precast yards, and logistics hubs.
Why they matter:
Safe handling of very heavy, unwieldy loads.
Less manual handling, fewer delays.
Lower risk during rigging, lifting, and transport inside facilities.
Support for pipelines, structural steel, and big machinery installs.
What This Install Includes
Runways & rails: continuous beams and rail caps.
End trucks: wheel assemblies that ride the rail.
Bridge girder(s): cambered and pre-wired.
Trolley & hoist: cross-travel carriage with lifting unit.
Electrics & controls: VFDs, radio remote, pendant.
Stops, bumpers & safety: overload protection, e-stops.
Based on design loads and bay geometry, you may be dealing with modest shop lifts or major industrial picks. The choreography is similar, but the scale, lift plans, and checks grow with the tonnage.
Make-Ready & Surveys
A clean install is mostly planning. Key steps:
Drawings & submittals: Approve general arrangement (GA), electrical schematics, and loads to the structure.
Permits/JSAs: Job Safety Analysis (JSA) for each lift step.
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: Mark crane components with ID tags.
People & roles: Brief everyone on radio calls and stop-work authority.
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: Check centerlines at intervals; confirm end squareness and expansion joints.
End stops & buffers: Install and torque per spec.
Conductor system: Keep dropper spacing uniform; ensure collector shoe reach.
Log final numbers on the ITP sheet. Misalignment shows up as crab angle and hot gearboxes—don’t accept it.
Lifting the Bridge
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.
Rig the bridge girder(s) and make the main lift.
Use drift pins to align flange holes; torque to spec.
Measure diagonal distances to confirm squareness.
Before anyone celebrates, bump-test long-travel motors with temporary power (under permit): ensure correct rotation and brake release. Lock out after test.
Hoist & Trolley
Trolley installation: Mount wheels, align wheel flanges, set side-clearances.
Hoist reeving: Check rope path, sheave guards, and equalizer sheaves.
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: Enable S-curve profiles for precise positioning.
Interlocks & safety: Zone limits near doors or mezzanines.
Cable management: Keep loops short, add drip loops where needed.
Commissioning crews love clean labeling and clear folders. If it isn’t documented, it didn’t happen—put it in the databook.
Trust but Verify
Inspection Test Plan (ITP): Hold/witness points for rail alignment, torque, electrical polarity, limit settings.
Torque logs: Re-check after 24 hours if required.
Level & gauge reports: Note any corrective shims.
Motor rotation & phasing: Confirm brake lift timing.
Functional tests: Jog commands, inching speeds, limits, overloads, pendant/remote range.
A tidy databook speeds client acceptance.
Proving the System
Static load test: Hold at mid-span and near end stops; monitor deflection and brake performance.
Dynamic load test: Check sway, braking distances, and VFD fault logs.
Operational checks: Limit switches trigger reliably; overload trips; horn/beacon function.
Training & handover: Operator basics, daily pre-use checks, rigging do’s & don’ts.
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: generator and turbine assembly.
Steel mills & foundries: hot metal handling (with the right duty class).
Warehousing & logistics: bulk material moves with minimal floor traffic.
Floor stays clear, production keeps flowing, and precision goes up.
Controls that Matter
Rigging discipline: dedicated signaler and stop-work authority.
Lockout/Tagout: test before touch every time.
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: re-check runway gauge and wheel alignment.
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.
Little noises are messages—listen early.
FAQ Snippets
Overhead vs. gantry? Choose per site constraints.
Single vs. double girder? Singles are lighter and cheaper; doubles carry heavier loads and give more hook height.
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.
Who Gets the Most Value
If you’re timber construction a civil or mechanical engineer, construction manager, shop supervisor, or just a mega-project fan, this deep dive makes the whole process tangible. You’ll see how small alignment wins become big reliability wins.
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