Back To Newsroom
Nuttall Gear Custom Gear Drives for Double-Leaf Bascule Bridge
The Pinellas County Department of Transportation in Florida recently completed
upgrades to the Park Boulevard double-leaf, bascule bridge. The bridge opened in
1981 and spans the intracoastal waterway to connect Seminole with Indian Shores on
the barrier islands. The bridge opens on demand for larger boats that sound their horn
or radio the bridge tender.
After over 30 years of service, the bridge’s original primary gearbox, which was
undersized, started to fail causing maintenance issues. The bridge upgrade included
replacement of the primary reducer, motor brakes and adjustment of air buffer
Nuttall Gear designed and manufactured new, larger primary gearboxes to drive both
bascule leafs. The drives featured fabricated steel housings. Per specification, all steel
materials were of USA origin and all welds were inspected by an Independent Certified
Weld Inspector (CWI).
Required no load, 150% load, and 200% load tests (in horizontal orientation), where
performed in-house. Nuttall technicians utilize the latest testing techniques and
technology including laser alignment of all drivetrain components, twin dynamometers
and massive custom-built test stands.
- Primary Differential Reducers:
Input rating: 120 HP @ 1171 RPM, Reduction ratio: 17.1:1,
Output torque rating: 74,000 lb.in.
- Custom-designed enclosed
with carburized and ground
- Two identical primary drives
- Fabricated steel housings
- All required testing