“Can this part be recreated?”

That was the question Mark Fazakerley asked as he examined a corroded and broken component retrieved from the sunken hull of his boat. It was a deceptively simple question—because this wasn’t just any part, and this wasn’t just any boat. 

The vessel was an original Mark I PBR (Patrol Boat, Riverine) from the Vietnam War, and the part in question was a 60-year-old pump housing, a vital component of the drive system. When the pump housing failed, it caused the boat to unexpectedly sink in Muskegon Lake.

Fazakerley’s connection to PBRs is both professional and deeply personal. A Navy veteran who served in the Vietnam War, he was nearly assigned to PBR duty before being assigned to LSD (Landing Ship, Dock) operations. His interest in PBRs reflects a lasting sense of connection to those who served on the rivers in Vietnam—some of whom are friends from his community in Muskegon who served aboard PBRs. To Mark Fazakerley, resurrecting the PBR wasn’t simply a repair project; it was a mission to honor the past and those who served.

To answer that call, AFS Corporate Member companies Eagle Alloy and Eagle CNC stepped in, both longtime leaders in metalcasting and machining. It was a fitting connection, as Mark Fazakerley also happens to be a co-founder of Eagle Alloy and board co-chair of both companies. What followed was a months-long collaboration among engineers, metalcasters and machining specialists, each bringing their expertise to the table to help restore a piece of naval history. 

A Sinking Setback Becomes an Opportunity

Mark Fazakerley’s PBR has been displayed at the Wings Over Muskegon Air Show on several occasions, and every Memorial Day it takes part in a Veterans Day event alongside the USS Silversides Submarine. Its operation provides a rare, hands-on connection to the past and stands as a living reminder of the courage and sacrifice of the brave men who served in the Vietnam War.

But as luck would have it, surviving a war didn’t spare it from peacetime trouble. During what should have been a routing outing, the boat suddenly sank. The PBR regularly gave rides on Muskegon Lake, and on this particular day, there was a loud noise aboard—then, without warning, the boat began rapidly taking on water. Passengers, including Mark’s son-in-law, had to jump overboard as the boat sank beneath them.

Within four minutes, PBR #161 had gone down in 53 feet of water. Fortunately, nearby fishermen came to the rescue of the passengers, and no one was injured. 

Mark thought he’d never see his boat again, but divers volunteered to help, using salvage balloons to raise it back to the surface. After inspecting the boat, the cause of the failure became clear: A chunk of the pump housing had broken apart. This component connects and protects the parts responsible for pumping water out and propelling the boat. When it failed, the system instead started rapidly pumping water into the boat instead of out, causing it to sink.

Each PBR has two of these housings, one on each side of the propulsion system. Given their age and identical material, it was decided to replace both of them. But there was an obstacle: The original parts were no longer manufactured, and Navy surplus had dried up decades ago. That’s when ingenuity kicked in, and Mark saw an opportunity to re-engineer the part with a little help from his friends.

“If I didn’t have direct access to a foundry and a machine shop, I wouldn’t have been able to reproduce this part. That would have been the end of the boat’s functional use,” Mark said.

Eagle Alloy and Eagle CNC took on the challenge. By combining Eagle Alloy’s casting expertise with Eagle CNC’s precision machining, they set out to reverse-engineer the part. This involved analyzing the damaged component to understand its structure and function, and then casting and machining it from scratch for even better performance and durability.

The Collaborative Process: From Scan to Cast

With no blueprints to work from, Eagle Alloy and Eagle CNC partnered closely from concept to completion, starting with a careful digital reconstruction and moving step by step through a modern manufacturing process. Eagle Alloy focused on mold design and preparing the casting, whereas Eagle CNC made sure the design and final product met all required specifications. 

3D Scanning and 3D Model Creation

The first step was to scan the original pump housings using 3D scanning technology. This created a detailed digital image of the part’s surface and shape. Haven Metrology handled this step, and they returned 3D scans of the original parts and a detailed 3D model to Eagle Alloy and Eagle CNC. These became the starting point for designing the mold for the casting and guiding the rest of the process.

Mold Design and Casting Simulation

Eagle Alloy took over to design the mold and run casting simulations in a digital environment. Their in-house engineers used 3D modeling and casting simulation software to create a casting plan.

The original pump housings were made with Ni-Hard iron, an extremely hard but also brittle material. An analysis of the broken part revealed extensive internal micro-cracking, and Eagle Alloy engineers concluded that embrittlement over time likely led to the part’s failure. 

Switching to stainless steel would best serve the product and offer durability and resistance to extreme temperatures. But first, Eagle Alloy had to be certain they could successfully manufacture the part using the alternative material.

Casting simulations, run in MAGMA software, were a key part of the planning process, especially because the new part would use a different material. Eagle Alloy’s engineers needed to optimize the mold’s gating systems and the pouring strategy to minimize the chances of defects. 

“The original part was made in iron, and iron flows much better than steel,” explained Eagle Alloy Engineering Manager Jason Klein. “The blades go down to almost one-eighth of an inch, so we had to make sure the metal was going to get there, and it was going to be hot enough to fill out all the nooks and crannies.”

At the same time, Eagle CNC did separate analyses. Their engineers noticed a lot of inconsistencies in the two original pump housings, which wasn’t necessarily a surprise given the technological advancements in manufacturing over the last 60 years. Taking the middle road, Eagle CNC established nominal measurements to ensure the new components would be consistent according to modern manufacturing standards.

The two companies communicated closely to ensure that the mold—and the resulting cast part—would include sufficient machine stock to allow Eagle CNC to carve out the critical dimensions.

Additionally, Eagle CNC got to work creating the brass inserts—the shaft bearings that threaded through the pump housing—from scratch. 

“I spent 2+ hours surgically removing the original part out of the broken housing,” said Brandon Mead, process engineering manager at Eagle CNC. “Once I had the old part out of the housing, I worked on reverse engineering the shape,” 

These inserts would later be threaded and screwed into the final pump housing, allowing the turbine shaft to spin and propel the boat.

3D Printing and Casting

Once the mold design of the new pump housing was ready, the physical mold was 3D printed by Ohio-based Humtown Products, which specializes in 3D-printed sand molds. While Eagle Alloy’s primary process is shell molding, 3D printed molding is an excellent option for prototypes and low-volume runs.

After printing, Humtown delivered the molds to Eagle Alloy to pour the metal castings. 

Getting the casting right took a few tries. The part’s complex internal structure made it necessary to switch from a two-piece to a three-piece mold for it to assemble properly, and that required several redesigns.

Despite the challenges, fast feedback and collaboration with Humtown allowed for quick adjustments, and the teams eventually arrived at a mold design that worked. Eagle Alloy then completed the pour in their foundry, and the cast part went to Eagle CNC to finish the job.

Machining at Eagle CNC

The machining team had already had a chance to study models and plan machining programs, but the real work started when they received the castings from Eagle Alloy. They set up custom tooling, designed fixtures to hold the workpieces, and measured meticulously throughout the process to ensure all the parts would fit together and function as planned.

Because this project had so much complexity, and a lot was on the line in terms of material and labor investment, Eagle CNC knew they had zero margin for error. 

Mead worked closely with Operation Black Sheep, a Muskegon-based non-profit dedicated to honoring the history of PBRs and the veterans who served on them. Black Sheep recently restored their own Mark II PBR, and they provided valuable insight into how the individual parts fit together to make the boat functional. They also stored Fazakerley’s PBR in their warehouse while it was out of service, offering easy access to the manufacturers for inspection.

“I was looking to understand the part and its application,” Mead said. “Just seeing holes in a part only goes so far; knowing what it’s for and understanding the mating components is essential. This will inform dimensions, tolerances, clearances and sometimes even improvements.”

Based in part on the new knowledge Mead gained from his visits to Black Sheep, Eagle CNC did go through a number of iterations of their original plan. They estimate that processing the first part took nearly two weeks. The second part, according to Eagle CNC President Jason Clark, took about four hours.

As a keystone partner in the collaboration, Eagle CNC’s work on the reverse-engineered pump housing showcased the breadth of their machining skills.

“We all knew we had the capability,” said Jason Clark. “It’s cool when you can actually test your engineering department with something like this and see it come to a product and a finished solution.”