MARAD Fast Sealift Ship (FSS) Re-Powering (2021-2022)

[Felocie]

Recently that_person submitted a FOIA request regarding a program to re-engine the Algol class FSS. These files are attached below, alongside an accompanying explanatory piece.

SeaLand Services, a now defunct American shipping line (RIP), constructed the eight 33-knot SL7-class container ships in the early 1970s. These 950-foot ships ran twin shafts on a 90MW steam powerplant. During their short operational life with SeaLand, they turned a steady profit, but continued operation became economically impossible due to the 1970s oil crisis. In the 50 years since, no similar ships have been built. These are truly unique vessels.

After the vessels were laid up, the USN took notice. Their size and speed made them perfect for surge sealift in REFORGER or Desert Shield-type operations. Because of this, the USN purchased all eight vessels in the 1980s, renamed them Algol-class Fast Sealift Ships (FSS), and had their center container hold converted to RORO garages. In this configuration, they have some 205k sq feet of RORO capacity.

They saw service in the Persian Gulf, before being transferred to MARAD’s Ready Reserve Fleet (RRF) in 2007. In the RRF, they would be retained to ROS-5 readiness at strategic outports across the CONUS, where they could be activated to provide initial “surge” sealift capacity in the event of conflict or national emergency. They remained in this status until 2025.

As of 2021, the vessels’ were in “great” material condition, and had only seen 11 years of sea time, despite being built in the early 70s. It was estimated that with proper refurbishment, their hull lived could be extended another 20-30 years. However, as the merchant marine transited away from steam, finding qualified engineers to run the aging steam plants became difficult. If the vessels were to be retained, their powerplants would require a complete refit. Knowing just how unique these vessels are, with no commercially available replacement for the high speed sealift role, MARAD commissioned TOTE Services (American shipping manager and vessel construction manager), and Bruce S. Rosenblatt & Associates (NavArc firm) to study “re-powering” options for the vessels. Phase I considered a wide variety of alternatives, ranging from automated steam, diesels, gas turbines, various combinations of the latter two, in direct and electric drive configurations. Eventually, it was decided to pursue an electric drive with three LM2500+ turbines. This would produce slightly less power than the existing plant, and thus speed would be reduced by 2-3 knots, but the vessels would be significantly easier to operate and maintain.

With the new plant selected, the study moved into Phase II. In order to remove the steam plant, the aft deckhouse would have to be removed. The forward pilothouse was also removed, and moved to a new aft deckhouse.

The cranes and mooring gear would also be replaced, a turtledeck built over the bow to protect against spray, and the aft container holds converted into RORO space. Total capacity expanded from ~205k to ~340k sq feet, just 50k less than a purpose-built LMSR (~7 knots slower).

Phase II came out to ~$373M in FY22 dollars, and MARAD asked for a more austere option to save on cost.

Phase III retained the basics of Phase II, but scaled down. The powerplant was reduced to 2x LM2500+G4s, further reducing speed (60MW vs 83MW). The aft container holds would still be converted to RORO garages, but these would not extend all the way to the keel. Total capacity now totaled 280k sq feet. The turtledeck was also deleted in favor of a more basic breakwater. Mooring gear and cranes would merely be refurbished, not replaced.
Phase III came out to $300M in FY22 dollars, a $73M reduction, but was ultimately not pursued.

Note: In the documents, RORO capacities are given as Military Usable Space, a 75% modifier of total capacity, assuming 25% is lost to lashing, spacing, etc. The numbers in this write up at 100% capacity.

This option was ultimately not pursued, and instead USTRANSCOM opted for more readily available commercial alternatives, and new domestic RORO production. This represented the death of high speed sealift.

Just 1 domestic construction RORO, built to a commercial design, costs $600M in FY23 dollars, when near identical ships can be bought second hand for $90M/hull. This highlights why restarting domestic production merchantmen is a fools errand, and should not be pursued. Strategic sealift is ultimately a numbers and cost efficiency game, not about where the vessels are built.

The Re-Powering options were considered to expensive compared to commercial alternatives, and ultimately not pursued. All eight vessels have been listed as non-retention status, and two have already been sold off. This represents the loss of a commercially irreplaceable assets, and the last great American naval architecture project.

Pics of FSS arriving at Brownsville:
https://www.facebook.com/groups/PicturesOfPadre/posts/3019062998304116
https://www.facebook.com/groups/PicturesOfPadre/posts/3023360127874403

Help save an SL7 / FSS:
https://sl7expo.org

Documents obtained by that_person via FOIA request with MARAD, February 2026.

The lined notebook paper contains notes from interview with naval architect from BSR.

Also attached is a variety of general documentation pertaining to the SL-7s/Algols, including general arrangement details.

Enjoy

 

[isayyo2]

Well done @Felocie and that_person.

I will miss @that_person's account - I very much enjoyed their insightful Naval postings.

 

[Felocie]

Well done @Felocie and that_person.

I will miss @that_person's account - I very much enjoyed their insightful Naval postings.

Hopefully there will still be more to come