Why Installation Decides Crane Life
Most single-girder EOT cranes that give trouble in the first two years were not badly built. They were badly installed. Flange wear, skewing, tripping hoists, a long travel motor that runs hot on one side — trace them back and you usually land on a runway that was out of tolerance on day one. Get the installation right and the same crane runs for two decades on routine greasing. This guide walks through the full sequence: pre-installation checks, runway and rail work, ground assembly, lifting the crane up, commissioning, and the load tests that sign it off. Numbers and tolerances included.
What a Single Girder EOT Crane Is
A single girder EOT crane runs one bridge beam across your bay, carried on two end carriages that travel along runway rails. The hoist hangs underneath on a trolley rather than sitting on top.
Where it fits best
- Capacities up to roughly 20 tonnes, spans up to about 25 metres
- Light to medium duty cycles — fabrication shops, warehouses, assembly lines, workshops
- Buildings where headroom is tight and every millimetre of hook height counts
- Projects where the runway steel budget matters, since a lighter bridge means lighter columns
Where it stops making sense
Push past 20 tonnes, or run three shifts of continuous handling, and the economics flip toward a double girder machine. Same goes for very long spans, where deflection on a single beam starts eating into your hook approach.
Pre-Installation Checks
Everything on this list happens before the crane reaches your gate. Skip a step here and you pay for it in idle labour later.
Site and building survey
Measure the actual bay, not the drawing. Buildings settle and as-built rarely matches as-designed. Record clear height from floor to underside of the roof truss, obstructions along the runway path, and every service line the crane will pass under.
Runway and column capacity
The runway girders and the columns supporting them must carry the crane’s dead weight plus the rated load plus impact and lateral forces. If the building was designed for a 5-tonne crane and you are installing a 10-tonne unit, the structure needs re-checking by a structural engineer. This is the single most common reason an installation stalls halfway.
Duty class and specification match
Confirm the crane’s duty class against your real usage — number of lifts per hour, average load as a fraction of rated capacity, hours of operation per shift. A Class I crane installed on a Class III application will not survive its warranty.
Power supply readiness
You need a dedicated supply at the correct voltage, an isolator near the runway, and proper earthing. Have the electrical contractor finish this before the erection team arrives, not during.
Drawings, approvals and clearances
Keep GA drawings, foundation and bracket details, wiring schematics, and the test certificate ready in one file. Where a statutory inspection applies, book the inspector early — waiting on an appointment can hold up production for a fortnight.
Tools, Equipment and Team You Need
- A mobile crane or two chain blocks with adequate capacity to lift the bridge to runway level
- Total station or laser level for runway alignment, plus a steel tape and piano wire for span checks
- Torque wrenches calibrated for the bolt grades on your drawing
- Welding set, if brackets are site-welded
- Certified slings, shackles and tag lines
- Scaffolding or a boom lift for rail and busbar work
- A team of four to six, including one licensed electrician and one supervisor who can read the GA drawing
Runway Beam and Rail Installation
Beam levelling and bracket fixing
Set the runway beams on their brackets and shim them to level before any rail goes down. Correcting elevation after the rail is fixed means undoing everything.
Rail laying and fastening
Lay the rail centred on the beam web. Use clips rather than continuous welding wherever the design allows — clipped rail can be adjusted later, welded rail cannot. Keep joint gaps to the drawing value and stagger joints on the two sides so both wheels never hit a joint at once.
Span, straightness and elevation tolerances
These are the numbers that matter most, drawn from BS 466, the standard commonly applied to overhead travelling cranes in India:
- Span: ±3 mm for spans under 12 m. Above 12 m, allow 3 + 0.25(S − 12) mm, where S is the span in metres.
- Horizontal straightness: 10 mm maximum deviation over the full bay, and no more than 1 mm per metre locally.
- Elevation: 1 mm per metre of span between the two rails, capped at 10 mm across the bay.
Check the diagonals too. Measure corner to corner across the runway at both ends; equal diagonals confirm the rails are square, not just parallel.
Busbar or DSL line installation
Mount the busbar on one side, clear of the crane’s swept path and of any material stacking zone. Support it at the spacing the manufacturer specifies — sagging busbar is a leading cause of collector shoe wear.
Ground Assembly of the Crane
Assembling at floor level is faster and safer than working at height. Do as much as the site allows.
Joining the main girder to the end carriages
Bolt the girder to the end carriages using the specified grade of high-tensile fasteners, and torque them in the sequence the drawing shows. Check the assembled span across the wheel flanges before lifting.
Mounting the hoist and trolley
Set the hoist on the lower flange, fit the end stops, and verify the trolley runs freely by hand along the full length. A trolley that binds on the ground will bind harder under load.
Panel, festoon and wiring
Fix the control panel at one end of the bridge. Run the festoon track, hang the cable trolleys, and dress the cable so it gathers cleanly without snagging. Terminate everything to the schematic and label both ends of every core.
Lifting the Crane onto the Runway
Rig the bridge from the designated lifting lugs only. Use tag lines to control rotation and land the wheels on the rails in one controlled movement, with a spotter on each end carriage. Once the wheels are seated, push the crane along the full runway by hand or on slow-speed drive to confirm nothing fouls.
Electrical Connection and Commissioning
Current collector setup
Mount the collector arms so the shoes sit square on the busbar with the specified spring pressure. Confirm phase sequence before energising — a reversed phase sends the long travel the wrong way into the end stop.
Trial runs and limit switch settings
Run each motion separately with no load. Set the hoist upper and lower limit switches, then the long travel and cross travel limits, so the crane stops with clearance to spare. Verify the emergency stop cuts all motions, and check brake performance on each drive.
Load Testing Sequence
No-load test
Every motion, full travel, both directions. Listen for anything unusual and check for temperature rise on the motors.
Rated load test
Lift 100% of rated capacity and run all motions through their full range. Measure girder deflection at mid-span and compare it to the design value on the drawing.
Overload test
OSHA 1910.179(k)(2) caps the test load at 125% of rated capacity unless the manufacturer says otherwise. Do the static test by lifting 125% a few inches off the floor and holding it, then check for permanent deformation. Follow with a dynamic test at 110% through the motions. Record everything and issue the test certificate.
Installation Mistakes That Cause Callbacks
- Aligning rails to the building instead of to each other. Structures are rarely square. The rails must be parallel to one another, whatever the walls are doing.
- Torquing bolts by feel. Under-torqued end carriage bolts loosen within months and show up as a knocking sound at each stop.
- Setting limit switches too tight. Operators then bump the limits constantly, and the switch fails from cycling.
- Skipping the deflection measurement. It is your only baseline for detecting girder fatigue five years from now.
Handover, Training and Documentation
Hand over the GA drawing, wiring schematic, hoist manual, test certificate, deflection reading, torque record, and the spares list in a single bound file. Train operators on the pendant or radio, the limit behaviour, and the daily pre-use check. Train the maintenance team separately on greasing points, brake adjustment and inspection intervals. Fix the first scheduled inspection date before the team leaves site.
FAQs
How long does a single girder EOT crane installation take? For a standard 5 to 10 tonne crane on a ready runway, budget two to four days for erection, commissioning and testing. If runway beams and rails are also part of the scope, add a week or more depending on bay length.
Can we install the crane while the plant is running? Partially. Ground assembly can happen alongside production, but the lift onto the runway and all rail work need the bay cleared below. Plan that window for a shutdown or a weekend.
What happens if the runway is out of tolerance? Shim and re-align before commissioning. Running a crane on a misaligned runway causes wheel skewing, which wears flanges and rails quickly and eventually damages the end carriages.
How often should the crane be inspected after installation? Daily visual checks by the operator, a monthly check of brakes, ropes or chains and limit switches, and a full documented inspection at least once a year.
Conclusion and Next Step
Installation is where a crane’s operating cost gets locked in. The tolerances, the torque values, and the test records are what separate a machine that runs quietly for twenty years from one that eats wheels. Work through the checks in order, document each stage, and hand the file to whoever maintains the crane next.
About Heben Cranes
Heben Cranes designs, manufactures and installs single girder EOT cranes built around your bay, your duty cycle and your building — not a catalogue number. Our installation teams work to published tolerances, load test on site, and hand over a complete documentation file with every crane.
Tell us your span, capacity and duty cycle, and we will send back a specification and installation plan for your site. Get in touch at hebencranes.com.
