Case Study: Overhaul of Pumps No. 1 & No. 5, Fox Point Hurricane Barrier, Providence, RI
Stephen Boudreau
- Client: U.S. Army Corps of Engineers (USACE)
- Contract Value: $3,055,699
- Duration: 2010–2012
- Contract No.: W912WJ-C-10-0013
- Location: Fox Point Hurricane Barrier, Providence, Rhode Island
- Contractor: Chas G. Allen, Inc.
Overview
Constructed in the 1960s following the devastating 1938 New England Hurricane, the Fox Point Hurricane Barrier safeguards the City of Providence against coastal flooding. The barrier’s five 650,000 GPM Worthington Hi-Flo pumps, each driven by a 4,500HP motor, are critical to the city’s storm defense infrastructure.
In 2010, USACE identified major failures in two of the pumps, No. 1 and No. 5, due to fractured propeller vanes. Chas G. Allen, Inc. was awarded a fixed-price contract to disassemble, inspect, overhaul, and recommission both units.
Project Challenges
Propeller Failure: The 119″ impellers had fractured vanes weighing over 600 lbs each, with Pump No. 1 missing an entire vane. The failure was linked to latent defects in the original 1960s Ni-Resist castings, including brittle material and poor vane hub root thickness design.
Degraded Components: Numerous parts, including shafts, bearings, columns, and diffusers, showed signs of erosion, cracking, pitting, and inadequate lubrication after decades in brackish water.
Legacy Design: Original hand-drawn schematics required reverse engineering and digitization for accurate fabrication and upgrades.
Environmental Safety: Paint and component materials contained lead; all cleaning and coating work had to meet stringent USACE and EPA environmental standards.
Our Approach
Engineering Analysis & Redesign: Leveraging digital modeling, our team identified structural weaknesses and improved the impeller design for better stress distribution and long-term durability.
Precision Repairs & Fabrication:
Fabricated a new propeller and keys for each unit.
Replaced lower bearing brackets with upgraded ductile Ni-Resist castings.
Rebuilt and upgraded lower and upper bearings using Monel 400 and 420SS materials.
Non-Destructive Testing (NDT): Conducted ultrasonic testing and precision alignment verification with tolerances under .002”.
Surface Preparation & Coatings: Applied Carboline and Belzona coating systems to restore and protect surfaces exposed to brackish water and high tidal activity.
Mechanical Systems Overhaul: Disassembled, cleaned, and rebuilt gearheads, sluice gate operators, anti-rotation brakes, lubrication systems, and electrical temperature monitoring.
Results
Pump No. 5 returned to service in November 2011.
Pump No. 1 was fully recommissioned by June 2012.
The project was delivered on time despite 20 change orders and external utility delays.
Received an “Outstanding” rating in the USACE final evaluation, including accolades for quality, responsiveness, documentation, and safety.
No reported safety incidents or compliance violations.
Services Provided
Full disassembly and inspection.
Reverse engineering and failure analysis.
Custom fabrication of propellers, shafts, and bearing components.
NDT, mechanical alignment, and precision assembly.
Environmental coatings and metal restoration.
Testing, documentation, and recommissioning.
