When loads get too big for forklifts and too precise for rough handling, teams turn to overhead cranes. This practical guide takes you behind the scenes of a mega-project crane install. We’ll cover rails and runway alignment—with the same checklists pro installers use.
What an Overhead/Bridge Crane Is
An overhead crane rides on parallel runways anchored to a building frame, carrying a trolley-mounted hoist for precise, vertical picks. The result is smooth X-Y-Z motion: cross-travel along the bridge.
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.
What This Install Includes
Runways & rails: runway girders with crane rail and clips.
End trucks: wheel assemblies that ride the rail.
Bridge girder(s): cambered and pre-wired.
Trolley & hoist: reeving, hook block, upper limit switches.
Electrics & controls: VFDs, radio remote, pendant.
Stops, bumpers & safety: end stops, buffers, travel limits.
Depending on capacity and span, 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
A clean install is mostly planning. Key steps:
Drawings & submittals: Approve general arrangement (GA), electrical schematics, and loads to the structure.
Permits/JSAs: Permit-to-work, hot work, working at height, rigging plans.
Runway verification: Check baseplates, grout pads, and anchor torque.
Power readiness: Lockout/tagout plan for energization.
Staging & laydown: Mark crane components with ID tags.
People & roles: Appoint a lift director, rigger, signaler, and electrical lead.
Millimeters at the runway become centimeters at full span. Spend time here.
Alignment That Saves Your Wheels
Runway alignment is the foundation. Targets and checks:
Straightness & elevation: shim packs under clips to meet tolerance.
Gauge (span) & squareness: Check centerlines at intervals; confirm end squareness and expansion joints.
End stops & buffers: Install and torque per spec.
Conductor system: Mount conductor bars or festoon track parallel to the rail.
Log final numbers on the ITP sheet. Correct now or pay later in wheel wear and motor overloads.
Girder Erection & End Trucks
Rigging plan: Softeners protect painted flanges. Taglines for swing control.
Sequence:
Lift end trucks to runway level and set temporarily on blocks.
Rig the bridge girder(s) and make the main lift.
Use drift pins to align flange holes; torque to spec.
Verify camber and bridge square.
Before anyone celebrates, bump-test long-travel motors with temporary power (under permit): ensure correct rotation and brake release. Lock out after test.
Cross-Travel Setup
Trolley installation: Mount wheels, align wheel flanges, set side-clearances.
Hoist reeving: Lubricate wire rope; verify dead-end terminations.
Limits & load 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.
Grinding noises mean something’s off—stop and inspect. Don’t mask issues with higher VFD ramps.
Electrics & Controls
Power supply: Drop leads tagged and strain-relieved.
Drive setup: Enable S-curve profiles for precise positioning.
Interlocks & safety: Zone limits near doors or mezzanines.
Cable management: Secure junction boxes; label everything for maintenance.
Future you will too. If it isn’t documented, it didn’t happen—put it in the databook.
QA/QC & Documentation
Inspection Test Plan (ITP): Hold/witness points for rail alignment, torque, electrical polarity, general construction company 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: 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: 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: handling long members safely.
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.
Do It Safe or Don’t Do It
Rigging discipline: dedicated signaler and stop-work authority.
Lockout/Tagout: clear isolation points for electrical work.
Fall protection & edges: scissor lifts and manlifts inspected.
Runway integrity: regular runway inspection plan.
Duty class selection: match crane class to cycles and loads.
Safety isn’t a stage—it's the whole show.
If It Doesn’t Run Smooth
Crab angle/drift: re-check runway gauge and wheel alignment.
Hot gearboxes: misalignment or over-tight brakes.
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.
Fast Facts
Overhead vs. gantry? Bridge cranes ride fixed runways; gantries walk on the floor.
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.
What You’ll Take Away
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 see how small alignment wins become big reliability wins.
Want ready-to-use checklists for runway surveys, torque logs, and load-test plans?
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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