In large construction and fabrication spaces, overhead/bridge cranes do the heavy lifting—literally. This long-form walkthrough shows how a full overhead crane system comes to life inside a structural building. You’ll see final load testing and handover—with the same checklists pro installers use.
What an Overhead/Bridge Crane Is
At heart, a bridge crane is a bridge beam that spans between two runway beams, with a trolley that travels left-right along the bridge and a hoist that lifts the load. The result is smooth X-Y-Z motion: and lift via the hoist.
You’ll find them in fabrication bays, steel plants, power stations, oil & gas shops, precast yards, and logistics hubs.
Why they matter:
Controlled moves for large, expensive equipment.
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: 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: VFDs, radio remote, pendant.
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.
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: Permit-to-work, hot work, working at height, rigging scaffold builder 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: Mark crane components with ID tags.
People & roles: Appoint a lift director, rigger, signaler, and electrical lead.
Tiny survey errors balloon into hours of rework. Measure twice, lift once.
Alignment That Saves Your Wheels
If rails are off, nothing else will run true. 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. Correct now or pay later in wheel wear and motor overloads.
Lifting the Bridge
Rigging plan: Choose spreader bars to keep slings clear of electricals. Taglines for swing control.
Sequence:
Lift end trucks to runway level and set temporarily on blocks.
For double-girder cranes, lift both girders with a matched raise.
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): ensure correct rotation and brake release. Lock out after test.
The Heart of the Lift
Trolley installation: Hoist/trolley arrives pre-assembled or as modules.
Hoist reeving: Lubricate wire rope; verify dead-end terminations.
Limits & load devices: Set upper/lower limit switches.
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: 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.
QA/QC & Documentation
Inspection Test Plan (ITP): Third-party witness for critical steps.
Torque logs: Record wrench serials and values.
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: 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: 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.
Do It Safe or Don’t Do It
Rigging discipline: rated slings & shackles, correct angles, spreader bars for load geometry.
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.
Keep It Rolling
Crab angle/drift: re-check runway gauge and wheel alignment.
Hot gearboxes: misalignment or over-tight brakes.
Rope drum spooling: check fleet angle and sheave alignment.
Pendant lag or dropout: shield noisy VFD cables.
Wheel wear & rail pitting: lubrication and alignment issues.
Little noises are messages—listen early.
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.
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.
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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