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. We’ll cover preparation and surveys—all explained in clear, real-world language.
Bridge Crane Basics
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 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.
High throughput with fewer ground obstructions.
System Components We’re Installing
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: VFDs, radio remote, pendant.
Stops, bumpers & safety: end stops, buffers, travel limits.
Depending on capacity and span, you may be dealing with modest shop lifts or major industrial picks. The installation flow stays similar, with heavier rigs demanding extra controls and sign-offs.
Before the First Bolt
A clean install is mostly planning. 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: 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: 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: 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.
Record as-built readings. 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. marine construction 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.
Measure diagonal distances to confirm squareness.
Prior to trolley install, bump-test long-travel motors with temporary power (under permit): confirm limit switch wiring. Lock out after test.
Cross-Travel Setup
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: Enable S-curve profiles for precise positioning.
Interlocks & safety: Zone limits near doors or mezzanines.
Cable management: Secure junction boxes; label everything for maintenance.
Commissioning crews love clean labeling and clear folders. 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, limit settings.
Torque logs: Record wrench serials and values.
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: 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.
Applications & Use Cases
Construction & steel erection: handling long members safely.
Oil & gas & power: moving heavy pumps, skids, and pipe spools.
Steel mills & foundries: large part transfer.
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: 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.
A perfect lift is the one nobody notices because nothing went wrong.
Troubleshooting & Pro Tips
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: shield noisy VFD cables.
Wheel wear & rail pitting: lubrication and alignment issues.
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
Students and pros alike get a front-row seat to precision rigging, structural alignment, and commissioning. 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?
Download your pro bundle so your next crane goes in cleaner, faster, and right the first time. Bookmark this guide and share it with your crew.
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