Two 275-Ton Dam Cranes, Rebuilt Instead of Replaced
AC drives, radio controls and full code compliance brought two hydroelectric gantry cranes back to like-new operating condition.
A major Northeastern hydroelectric power authority relies on two 275-ton gantry cranes to raise and lower the dam's water control gates. After decades of service, both were out of code, worn, and running on DC drives that could no longer position gates precisely.
Han-Tek modernized both cranes in place instead of replacing them: AC drives on all five motions, radio remote control, new motors, gear reducers and brakes, structural repairs, and full OSHA, CMAA and NEC compliance.
Critical cranes that had fallen behind code
The two gantry cranes ride along the top of the dam and lift the gates that control water flow. Gate position decides how much water passes, so every move has to be precise and repeatable. After decades in service, neither crane could do that reliably.
Old DC drives
No smooth, variable-speed control, which made accurate gate positioning hard.
Out of code
Missing wind anemometers and rail clamps, unrated load markings, and gaps against OSHA, CMAA and NEC.
Worn and cracked
An engineering study found worn pins, drums, brakes and seals, plus cracked welds in the gantry legs.
Operators also had to climb up and run the cranes at dangerous heights on every cycle.
Modernize both cranes in place
Instead of replacing two 275-ton cranes, Han-Tek rebuilt both as single-point contractor, with P&H as the crane OEM partner for structural and mechanical work.
- Drives: Magnetek VG+ AC drives on the main and auxiliary hoists and G+ drives on the bridge, trolley and gantry, replacing DC on all five motions.
- Controls: Cattron Theimeg MP96 radio remotes, so operators run both cranes from the dam deck.
- Components: new motors, SEW Eurodrive gear reducers, Hillmar/Mondel brakes, EMS festoon, Cutler-Hammer NEC-compliant panels and integrated load cells.
- Code and safety: wind anemometers, rail clamps, rated load markings and cage modifications.
- Mechanical and structural: redesigned truck saddle pins, drum and sheave repairs, new seals and hoist rope, and weld repairs found by non-destructive testing.
Both cranes were brought to like-new operating condition at a fraction of the cost and disruption of replacing them.
Precise, code-compliant and safer to run
| Area | Before | After |
|---|---|---|
| Gate positioning | DC drives, no smooth variable speed | Infinitely variable on all five motions |
| Operator location | At height on the crane | Dam deck, by radio remote |
| Code status | Out of OSHA, CMAA and NEC compliance | Fully compliant |
| Engineering study items | Open on both cranes | All addressed |
- Gate positioning restored: variable-frequency drives give precise, repeatable gate moves the old DC system could not.
- No more work at height: operators run both cranes from the dam deck.
- Full code compliance: both cranes now meet current OSHA, NEC and CMAA requirements.
- Critical assets preserved: two 275-ton cranes back in like-new condition without the cost of replacement.
Questions about crane modernization
Is modernizing a crane better than replacing it?
Often, when the structure is sound. On this project both cranes were rebuilt in place to like-new operating condition at a fraction of the cost and disruption of replacement.
Can a DC crane be converted to AC drives?
Yes. All five motions on both cranes moved from DC to Magnetek AC variable-frequency drives, with new motors matched to the drives.
How do radio remotes improve crane safety?
Operators run the crane from a safe spot on the ground or deck, so nobody has to climb or ride the crane to operate it.
Which codes apply to gantry and overhead cranes?
OSHA, CMAA and NEC all set requirements. This project brought both cranes into compliance with all three.
More crane projects
Modernize or replace? Let's find out.
Send us the crane make, capacity and what it is doing today. A Han-Tek engineer will tell you what a modernization would take.
"*" indicates required fields