ArcelorMittal Dofasco (AMD)
Slab Yard Crane DC Drive Retrofit & Controls Modernization
New Life for a 30-Year-Old Slab Yard Crane
Project Overview
SAF Drives completed a full controls and drive retrofit for ArcelorMittal Dofasco’s #19 LeTourneau Slab Yard Crane in Hamilton, Ontario. The 50-ton rubber-tired gantry crane, operating 24/7 and averaging 400 lifts per day, required a modernization solution that replaced legacy controls and drives while retaining the existing DC motors. The retrofit was engineered for harsh outdoor conditions and limited diesel-generator power, delivering improved precision control, faster response, and increased reliability.
Key Takeaways:
- Complete crane controls and drive retrofit while retaining existing DC motors
- Designed for outdoor steel operations from -30°C to +40°C
- Harmonics reduced from ~100% RMS to ~10% RMS
- Improved precision control, fast response, and increased reliability
- Result: became AMD’s preferred slab yard crane
The Challenge
Modern control without replacing the DC motors
ArcelorMittal Dofasco (AMD) needed new controls for their #19 LeTourneau Slab Yard Crane at their Hamilton steel facility. The crane is a 50T rubber-tired gantry crane, powered by a diesel-electric power unit, and used for continuous slab movement.
This crane operates 24/7, averaging 400 lifts per day, meaning downtime wasn’t an option.
The upgrade required SAF to:
- replace all crane controls and drives
- keep the existing DC motors
- ensure modern technology worked seamlessly with legacy components
Key Constraints:
Limited available power
diesel generator-driven system
Outdoor Operation
Outdoor Hazards
Extreme Ambient Temperatures
From -30°C to +40°C
SAF’s Solution
A purpose-built retrofit engineered for harsh-duty steel operations
To support outdoor operation and protect critical equipment, SAF supplied a new E-house to house the upgraded control infrastructure.
The Solution Included:
Solution:
new SAF DD312 regenerative DC
Drive cabinets
Solution:
PLC and SAFphire control cabinet
Solution:
MCC section
Harmonics reduction: solving a critical generator constraint
To ensure proper diesel generator performance, SAF needed to significantly reduce harmonics. A unique 24-pulse configuration was implemented on the traction motors.
Result: harmonics were reduced from approximately 100% RMS to about 10% RMS; a major reduction.
Dynamic braking for regenerative control
Because the system could not regenerate back to the diesel generator, SAF implemented a dynamic braking system connected to the AC bus to capture braking energy.
A unique SAFphire control algorithm was also implemented to ensure total current stayed within safe limits for both:
- generator motoring conditions
- braking resistor regeneration conditions
Performance outcome
Optimized Operation in all Four Quadrants
The fast dynamic response of the regenerative drives provided optimized crane operation in all four quadrants:
Outcome:
motoring forward and reverse
Outcome:
braking forward and reverse
results
Precision Control, Faster Response, and Improved Reliability
The upgraded crane delivered immediate performance improvements.
Operators Reported:
Result:
Precision Control
Result:
Fast Response
Maintenance & Management Teams Saw:
Result:
Improved efficiency
Result:
Increased Reliability
NET RESULT
AMD’s LeTourneau Crane #19 became the preferred crane in the ArcelorMittal Dofasco slab yard.
“The upgrade of AMD’s Letourneau Crane #19 was a complete success. The SAF team did their homework to ensure that all of our operational, technical and safety needs were met… The crane now runs flawlessly.”
– Jerry Pruden, Electrical Trade Specialist, AMD
TAKEAWAY
Why This Matters for Industrial Steel Operations
This project highlights what SAF does best: delivering retrofit performance in uptime-critical steel environments where the equipment is legacy, the constraints are real, and failure isn’t acceptable.
SAF helps steel teams modernize without unnecessary replacement by engineering solutions that fit the application, power limitations, and operating conditions.
Request a drive Obsolescence & Downtime Risk Review
If you’re operating aging drive/control systems — or managing DC equipment that’s becoming harder to support — SAF can help identify your top risks and map a practical retrofit path.