Overhead cranes—often called bridge cranes—are the quiet workhorses that keep heavy industry moving. This long-form walkthrough shows how a full overhead crane system comes to life inside a structural building. We’ll cover rails and runway alignment—with the same checklists pro installers use.
Overhead Crane, Defined
At heart, a bridge crane is a bridge beam that spans between two runway beams, carrying a trolley-mounted hoist for precise, vertical picks. The result is smooth X-Y-Z 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:
Controlled moves for large, expensive equipment.
Huge efficiency gains.
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: motorized gearboxes for long-travel.
Bridge girder(s): cambered and pre-wired.
Trolley & hoist: cross-travel carriage with lifting unit.
Electrics & controls: power supply, festoon or conductor bars.
Stops, bumpers & safety: overload protection, e-stops.
Depending on capacity and span, the crane might be a single-girder 10-ton unit or a massive double-girder 100-ton system. The choreography is similar, but the scale, lift plans, and checks grow with the tonnage.
Before the First Bolt
Good installs start on paper. Key steps:
Drawings & submittals: Freeze the GA and verify reactions with the structural team.
Permits/JSAs: Job Safety Analysis (JSA) for each lift step.
Runway verification: Check baseplates, grout pads, and anchor torque.
Power readiness: Lockout/tagout plan for energization.
Staging & laydown: Lay out slings, shackles, spreader bars, and chokers per rigging plan.
People & roles: Brief everyone on radio calls and stop-work authority.
Millimeters at the runway become centimeters at full span. Measure twice, lift once.
Getting the Path Right
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: 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: Softeners protect painted flanges. Dedicated signaler on radio.
Sequence:
Lift end trucks to runway level and set temporarily on blocks.
Rig the bridge girder(s) and make the main lift.
Land the bridge on the end trucks and pin/bolt per GA.
Measure diagonal distances to confirm squareness.
Before anyone celebrates, bump-test long-travel motors with temporary power (under permit): confirm limit switch wiring. Lock out after test.
Hoist & Trolley
Trolley installation: Hoist/trolley arrives pre-assembled or as modules.
Hoist reeving: Lubricate wire rope; verify dead-end terminations.
Limits & load m&m construction devices: Check overload/SLI and emergency stop.
Cross-travel adjustment: Align trolley rails on a double-girder.
Pendant/remote: Install pendant festoon or pair radio receiver; function-test deadman and two-step speed controls.
A smooth trolley with a quiet hoist is a sign of good alignment. 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.
Future you will too. Photos of terminations help later troubleshooting.
ITP, Checklists, and Sign-Off
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: Attach survey prints.
Motor rotation & phasing: Document bump tests.
Functional tests: Anti-collisions and zone interlocks.
QA/QC is not paperwork—it’s your warranty in a binder.
Proving the System
Static load test: Apply test weights at the hook (usually 100–125% of rated capacity per spec).
Dynamic load test: Travel long-run, cross-travel, and hoist at rated speed with test load.
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: high throughput lanes.
Once teams learn the motions, cycle times drop and safety improves.
Do It Safe or Don’t Do It
Rigging discipline: dedicated signaler and stop-work authority.
Lockout/Tagout: test before touch every time.
Fall protection & edges: scissor lifts and manlifts inspected.
Runway integrity: regular runway inspection plan.
Duty class selection: overspec when uncertainty exists.
A perfect lift is the one nobody notices because nothing went wrong.
Troubleshooting & Pro Tips
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: shield noisy VFD cables.
Wheel wear & rail pitting: add rail sweeps and check clip torque.
A 10-minute weekly check saves days of downtime later.
Quick Answers
Overhead vs. gantry? Choose per site constraints.
Single vs. double girder? Span and duty class usually decide.
How long does install take? Anything from a couple weeks to a few months.
What’s the duty class? FEM/ISO or CMAA classes define cycles and service—don’t guess; size it right.
Why Watch/Read This
If you’re 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 gain a checklist mindset that keeps cranes safe and productive.
Looking for a clean handover databook index you can reuse on every project?
Grab the installer pack so your next crane goes in cleaner, faster, and right the first time. Save it to your site tablet for quick reference.
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