For decades, families from around the globe have enjoyed cruising the open waters of the Atlantic Ocean, The Gulf of Mexico, and the Caribbean, while feasting on lavish buffets and enjoying all the amenities cruise ships have to offer. The COVID-19 pandemic wreaked havoc on the cruise industry for nearly two years. Now that the pandemic has finally ended, the industry is poised to come back even bigger and stronger than ever before. On November 20, 2022, Carnival Cruise Line (CCL) welcomed their new flagship vessel, The Carnival Celebration, to their homeport in South Florida, Port Miami.

This new vessel has a layout that consists of overhanging lifeboats extending further inland than their other, older vessels. When berthed at Port Miami, this new layout created a potential conflict between the overhanging lifeboats and the passenger boarding bridges' (PBB) structural frame. Unfortunately, the passenger boarding bridges (PBB) are fixed in the North/South position due to the heavy point loads of this equipment, and the need to lay on the pile supported runway foundation system on the apron. The only other way to achieve a proper and safe distance between the overhanging lifeboats and the PBB was to create a standoff between the vessel and the seawall. That’s where the idea for the fender backing frames was born.

Multiple studies were conducted in order to find the “sweet spot” the standoff needed. The port was restricted in both directions for two reasons. First, the overhanging lifeboats could not be less than a set distance off the frame of the PBB, and second, the standoff could not be greater than the maximum reach of the PBB telescopic tunnels. The final standoff distance was calculated to be 3’6”. A 3’6” steel frame backing behind the foam filled fenders was sought out as it provided the proper rigidity to withstand the forces acted upon by the cruise vessels.

Once the design and engineering of the steel frames was complete, it was time to fabricate. When Port Miami chose Metro Steel USA to fabricate and build these frames, they had two things in mind: quality and service. The window of opportunity was small, which meant that the owner, fabricator, and galvanizer had to work together seamlessly to ensure that the frames were delivered on time to the port. Communication was key in order to guarantee success. There were (8) frames in all, and each frame was approximately 14’ x 12’ and weighing just over 15,000lbs each. The frames were fabricated with square tubing which meant that each piece of hollow tubing required vent & drain holes to be strategically located according to ASTM A385, therefore allowing air to escape during immersion into the zinc kettle, and the zinc to drain freely during extraction from the zinc kettle. Because of the overall dimensions of the frames, the galvanizer had to utilize a progressive dip technique which allowed them to hot-dip galvanize every square inch of the frames.

So why hot-dip galvanizing? The decision was actually quite simple. Port Miami needed a coating that was capable of withstanding the harsh saltwater environment at the seaport, while also being aesthetically appealing to the hundreds of thousands of future travelers that will soon be passing through the cruise terminal. Anthony Gil, Project Engineer with Port Miami stated, “As you are aware, bare steel becomes quickly corroded in a harsh saltwater environment, which prompted the need for hot-dip galvanizing.” The Time-To-First Maintenance for a project this size, in a tropical marine environment, is expected to be between 55-75 years. This gives Port Miami and Carnival Cruise Lines decades of maintenance-free life from these frames.