In large construction and fabrication spaces, overhead/bridge cranes do the heavy lifting—literally. This practical guide takes you behind the scenes of a mega-project crane install. You’ll see final load testing and handover—all explained in clear, real-world language.
What an Overhead/Bridge Crane Is
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 result is smooth X-Y-Z 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:
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: continuous beams and rail caps.
End trucks: wheel assemblies that ride the rail.
Bridge girder(s): single- or double-girder configuration.
Trolley & hoist: reeving, hook block, upper limit switches.
Electrics & controls: garage construction power supply, festoon or conductor bars.
Stops, bumpers & safety: overload protection, e-stops.
Depending on capacity and span, you may be dealing with modest shop lifts or major industrial picks. The installation flow stays 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: Freeze the GA and verify reactions with the structural team.
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.
Millimeters at the runway become centimeters at full span. Measure twice, lift once.
Getting the Path Right
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: 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.
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. Dedicated signaler on radio.
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.
Prior to trolley install, bump-test long-travel motors with temporary power (under permit): confirm limit switch wiring. Re-apply LOTO once checks pass.
The Heart of the Lift
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.
A smooth trolley with a quiet hoist is a sign of good alignment. Fix the mechanics first.
Drive Tuning & Interlocks
Power supply: Drop leads tagged and strain-relieved.
Drive setup: Program VFDs for soft starts, decel ramps, and brake timing.
Interlocks & safety: Zone limits near doors or mezzanines.
Cable management: Keep loops short, add drip loops where needed.
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: Document bump tests.
Functional tests: Jog commands, inching speeds, limits, overloads, pendant/remote range.
QA/QC is not paperwork—it’s your warranty in a binder.
Load Testing & Commissioning
Static load test: Hold at mid-span and near end stops; monitor deflection and brake performance.
Dynamic load test: Travel long-run, cross-travel, and hoist at rated speed with test load.
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.
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: high throughput lanes.
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: 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.
If It Doesn’t Run Smooth
Crab angle/drift: re-check runway gauge and wheel alignment.
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.
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? 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.
What You’ll Take Away
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?
Get the toolkit now and cut hours from setup while boosting safety and QA/QC. Bookmark this guide and share it with your crew.
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