When loads get too big for forklifts and too precise for rough handling, teams turn to overhead cranes. This practical guide follows the journey from bare runways to a commissioned crane ready for service. You’ll see hoist and trolley setup—all explained in clear, real-world language.
Bridge Crane Basics
An overhead crane rides on parallel runways anchored to a building frame, with a trolley that travels left-right along the bridge and a hoist that lifts the load. The system delivers three axes of 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:
Controlled moves for large, expensive equipment.
Huge efficiency gains.
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: wheel assemblies that ride the rail.
Bridge girder(s): cambered and pre-wired.
Trolley & hoist: reeving, hook block, upper limit switches.
Electrics & controls: power supply, festoon or conductor bars.
Stops, bumpers & safety: end stops, buffers, travel limits.
Based on design loads and bay geometry, the crane might be a single-girder 10-ton unit or a massive double-girder 100-ton system. The choreography is similar, with heavier rigs demanding extra controls and sign-offs.
Pre-Install Prep
A clean install is mostly planning. Key steps:
Drawings & submittals: Approve general arrangement (GA), electrical schematics, and loads to the structure.
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: Appoint a lift director, rigger, signaler, and electrical lead.
Tiny survey errors balloon into hours of rework. Spend time here.
Getting the Path Right
If rails are off, nothing else will run true. Targets and checks:
Straightness & elevation: shim packs under clips to meet tolerance.
Gauge (span) & squareness: Use feeler gauges on splice bars, torque rail clips.
End stops & buffers: Verify clearances for bumpers at both ends.
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.
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.
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.
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: 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. Don’t mask issues with higher VFD ramps.
Power with Discipline
Power supply: Drop leads tagged and strain-relieved.
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.
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, limit settings.
Torque logs: Re-check after 24 hours if required.
Level & gauge reports: Attach survey prints.
Motor rotation & phasing: Confirm brake lift timing.
Functional tests: Anti-collisions and zone interlocks.
A tidy databook speeds client acceptance.
Load Testing & Commissioning
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.
When the logbook is clean, the crane is officially in service.
Applications & Use Cases
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: high throughput lanes.
Once teams learn the motions, cycle times drop and safety improves.
Safety & Engineering Considerations
Rigging discipline: rated slings & shackles, correct angles, spreader bars for load geometry.
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: match crane class to cycles and loads.
A perfect lift is the one nobody notices because nothing went wrong.
Keep It Rolling
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? Choose per site constraints.
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.
Looking for a clean handover databook index you can reuse on every project?
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