Overhead cranes—often called bridge cranes—are the quiet workhorses that keep heavy industry moving. This long-form walkthrough shows how a full overhead crane system comes to life inside a structural building. We’ll cover preparation and surveys—with the same checklists pro installers use.
Overhead Crane, Defined
At heart, a bridge crane is a bridge beam that spans between two runway beams, with a trolley that travels left-right along the construction png bridge and a hoist that lifts the load. The system delivers three axes of 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.
Huge efficiency gains.
Lower risk during rigging, lifting, and transport inside facilities.
High throughput with fewer ground obstructions.
What This Install Includes
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.
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
Good 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: 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. Measure twice, lift once.
Rails & Runways
If rails are off, nothing else will run true. 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: 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. Misalignment shows up as crab angle and hot gearboxes—don’t accept it.
Putting the Span in the Air
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.
Use drift pins to align flange holes; torque to spec.
Measure diagonal distances to confirm squareness.
Before anyone celebrates, bump-test long-travel motors with temporary power (under permit): confirm limit switch wiring. Lock out after test.
Hoist & Trolley
Trolley installation: Mount wheels, align wheel flanges, set side-clearances.
Hoist reeving: Check rope path, sheave guards, and equalizer sheaves.
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. Fix the mechanics first.
Electrics & Controls
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: 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.
Trust but Verify
Inspection Test Plan (ITP): Third-party witness for critical steps.
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: Jog commands, inching speeds, limits, overloads, pendant/remote range.
QA/QC is not paperwork—it’s your warranty in a binder.
Ready for Work
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: Operator basics, daily pre-use checks, rigging do’s & don’ts.
When the logbook is clean, the crane is officially in service.
Where These Cranes Shine
Construction & steel erection: placing beams, trusses, and precast.
Oil & gas & power: generator and turbine assembly.
Steel mills & foundries: large part transfer.
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: dedicated signaler and stop-work authority.
Lockout/Tagout: test before touch every time.
Fall protection & edges: scissor lifts and manlifts inspected.
Runway integrity: no cracked welds, correct bolt grades, proper grout.
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: verify end-truck wheel diameters and gearbox mounts.
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: add rail sweeps and check clip torque.
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 see how small alignment wins become big reliability wins.
Looking for a clean handover databook index you can reuse on every project?
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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