In large construction and fabrication spaces, overhead/bridge cranes do the heavy lifting—literally. This long-form walkthrough follows the journey from bare runways to a commissioned crane ready for service. 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, 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.
Less manual handling, fewer delays.
Lower risk during rigging, lifting, and transport inside facilities.
High throughput with fewer ground obstructions.
Scope at a Glance
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: reeving, hook block, upper limit switches.
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 installation flow stays similar, but the scale, lift plans, and checks grow with the tonnage.
Pre-Install Prep
Good industrial construction installs start on paper. 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: 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.
Tiny survey errors balloon into hours of rework. Measure twice, lift once.
Rails & Runways
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: Verify clearances for bumpers at both ends.
Conductor system: Keep dropper spacing uniform; ensure collector shoe reach.
Record as-built readings. 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. 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.
Use drift pins to align flange holes; torque to spec.
Verify camber and bridge square.
Prior to trolley install, bump-test long-travel motors with temporary power (under permit): confirm limit switch wiring. Re-apply LOTO once checks pass.
Cross-Travel Setup
Trolley installation: Hoist/trolley arrives pre-assembled or as modules.
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.
A smooth trolley with a quiet hoist is a sign of good alignment. 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: E-stops, limit switches, anti-collision (if multiple cranes), horn, beacon.
Cable management: Keep loops short, add drip loops where needed.
Future you will too. If it isn’t documented, it didn’t happen—put it in the databook.
ITP, Checklists, and Sign-Off
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: 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: Apply test weights at the hook (usually 100–125% of rated capacity per spec).
Dynamic load test: Check sway, braking distances, and VFD fault logs.
Operational checks: Emergency stop shuts down all motions.
Training & handover: Operator basics, daily pre-use checks, rigging do’s & don’ts.
Only after these pass do you hand over the keys.
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.
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: regular runway inspection plan.
Duty class selection: overspec when uncertainty exists.
Safety isn’t a stage—it's the whole show.
If It Doesn’t Run Smooth
Crab angle/drift: verify end-truck wheel diameters and gearbox mounts.
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: lubrication and alignment issues.
A 10-minute weekly check saves days of downtime later.
FAQ Snippets
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
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.
Need a field bundle with JSA templates, rigging calculators, and commissioning sheets?
Grab the installer pack and cut hours from setup while boosting safety and QA/QC. Save it to your site tablet for quick reference.
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