Columbia Class Troop Carriers: Mixing Up The Fleet Mix

by Craig Hooper on July 19, 2021

After three generations of converting surplus/obsolete SSBN hull forms to commando carriers, it’s time to start planning for a Columbia Class commando-carrying variant. Despite a lot of classification, open records suggest undersea commando carriers have accumulated a record of success that stretches back to World War II. And with the Marine Corps already organizing their basic amphibious warfare elements to fit into the operational parameters of SSBN-sized commando-carrying sub, it is probably something the Navy should start openly discussing with Congress and the Industrial Base.

I can hear the “tut-tutting” now. Too expensive, you say? Well, if we start looking at different fleet mixes (something that we’re not doing a great job of), where the amphibious-oriented surface fleet becomes a mix of low-cost LAWs and ESBs and some other things, a brace of modified troop-carrying Columbia class subs doesn’t look like that much of a stretch. Look, I love amphibious vessels, but a 2-billion dollar a hull LPD/LSD is…a lot. And popping in a few extra Columbia class variants on the latter part of the production run for the Columbia class’ existing 12 hull SSBN program of record might do good service right now in driving down the per-hull cost of the big sub.

Ahh, but the critics will then say that legacy amphibious vessels are too useful. Sure! They are useful–heck, they’re so valuable we’re simply lighting them on fire and burning them to the waterline while pierside, yes! But, all quips aside, are we using them as effectively as we can be? Are they a good ROI? The amphibious fleet has not been out there making headlines lately, and, for that matter, for the vast majority of amphibious lift missions, we don’t need a 2 billion-dollar LPD or a 3-6 billion dollar LHA/LHD to carry them out. An ESB ain’t necessarily the totally right answer either, but, hell, it’s a start.

This is going to cause a lot of heartache, but General Berger is right. The era of fielding amphibious fleet of only expensive glass-cannon amphibious vessels is coming to a close–it’s time to accept that lower-cost ships can do amphibious lift just fine, and recognize that some sort of undersea approach may well be the future of amphibious assault in contested areas. It might well be time to “get real” about reorienting the existing amphibious fleet industrial base towards small sea-control aircraft carriers, ramp down the rate of LPD/LSD production, and then get about fielding a bunch of low-cost amphibious vessels.

Anyway, I digress. I think a Columbia Class troop-carrying sub variant is idea worth mulling, and I’ve written up a more involved piece over at (here) detailing the proposal. Enjoy!

{ 7 comments… read them below or add one }

TMark August 27, 2021 at 11:09 pm

Too many utter the word “Marines” and assume they’re just light troops who run with rifles, so dispatching them through submarine top hatches must be good enough for amphibious assault. But that’s not amphibious assault. Current doctrine has over 2/3rds of personnel helo lifted ashore, but over 3/4ths of their tonnage (armored vehicles, heavy weapons, trucks, ammo, fuel, food, supplies, etc.) are delivered by surface connectors. The helo lifted troops won’t last 24 hours without the surface logistical train. (BTW, converting to an entirely helo lifted regime of both forces and logistics would only result in an over-stressed and deadlined air element after 12 hours.)

That said, a Columbia Class ‘troop carrier’ submarine won’t feature a well deck for vehicles or palletized supplies, to say nothing of any connectors for delivery to shore. Nor would it be conducive to helo interoperability with an Amphibious Ready Group and their embarked MEU/MEB/MEF. Qualifying a Marine company for sub service (and swimming half a mile) is another challenge, and would they reenlist knowing liberty ports (and sunshine) are limited? All that money for a nuclear powered one-trick pony that can only dispatch 60 wet riflemen? SSNs inserting a SEAL unit is fine, as neither the sub or SEALs sacrifice any capacity for other missions. But a detachment of non-supplied ‘light’ Marines with no heavy weapons on a mostly disarmed sub defeats the purpose of both.


Keith August 2, 2021 at 1:30 pm

Actually on the surface or under it- ha- this is not a bad idea in one regard, the toughest ship to detect in the sea is a sub. I’d argue though if you are going to go the route of replacing ships capable of hauling extreme amounts of men and material, I’d not use the Columbia class just to lower hull costs, as it seems the next gen attack sub will help do that. I’d look more to a very large sub, let’s think the dreaded Russian Typhoon missile subs, but instead of making it a 12 billion dollar sub in that regard, it needs to do a few things and do them well. A. Store as much materials as possible, which could mean a Battalion’s worth of vehicles, yes, Armor included. B. Stay quiet, which huge double hulled subs traditionally are quiet. C. berths for the added troops. D. can take a torpedo hit, which with size and hull type probably could be done. I’d add don’t waste a ton of $ on updated mid-hull sensors and both flank and stern arrays, use what you need to find and fix any potential enemy subs, and don’t waste large amounts of space on torpedo or missile storage, basically a couple of tubes to snap off defensive shots. It will probably not dive as deep, because it will need a way to “open” if you will to allow the ability to disembark the troops and vehicles. I’m not sure what depth it could manage knowing that, but whether it’s an LST type front break (maybe impossible) or a sloped tunnel entrance vehicles can leave through and ride down a bridge plank, whom knows. It’s not storming a beach, and again, main mission, get that mass of men and machines from point A to point B quietly and at least get 300 feet below the surface, and yes, it’s going to be very, very big. But steel is cheap and sailors are not, so in this case, you need not have tons of weapon experts, just the crew to ensure she runs for 2-3 weeks, not months.


Bill Smith July 31, 2021 at 10:39 am

Honestly, a better option would be a Seawolf follow-on, or more-specifically, a Jimmy Carter designed from a clean sheet of paper. Larger hull volume than Virginias, but smaller diameter than Columbias and with better range than HI Sutton’s diesel sub. They could have large numbers of Tomahawk (follow-on) tubes arranged more beneficially than VPMs, retain undersea warfare capability of an SSN, and have a multi-use space of great size, compartmented into “wet” and “dry” sides. In Amphib-mode the dry side carries Marines and the wet-side carries equipment and CRRCs. In Commando-mode, the dry side carries SEALs and the wet-side their undersea toys. In Spy-mode, the dry side carries an ROV operations center and intelligence processing facility while the wet side has ROVs, operational equipment, and storage for “bring backs.” A class of 12 or more would allow better dispersion of capabilities in spy-mode, Commando-mode, and SSGN-mode, as well as allowing some concentration to make up to Btln.-sized USMC operations possible. A final aspect of this dispersion is that with ROVs aboard, it would give rapid-response assistance to submarine rescue forces too.


Craig Hooper July 20, 2021 at 5:44 am

Let’s not overlook the advantage the Colombia’s space/volume offers. There’s a lot of goodness there that can be used for various things.


James O'Keefe July 23, 2021 at 2:58 pm

Sure, but as BSmitty notes each would be $9.4 billion. That is nearly 2/3 the cost of a Ford CVN. Doubtless it would carry a lot of cruise missiles and would be very quiet, but it would also be very wide/deep which would hinder its ability to get close to shore.

Using the VPM Virginia SSNs gets you two subs though perhaps not with the same number of troops, but also not putting all your eggs in one basket.

Even at $1 billion a ship, which seems too high, HI Sutton’s Shallow Water Submarine gets you nine subs with lower individual numbers of SEALs/Marines, but perhaps a larger number overall. The cost would be in range, speed and, perhaps, crew comfort.


James O'Keefe July 19, 2021 at 3:28 pm

BSmitty – Good point, but as a replacement for all of the roles the SSGNs currently have, the Columbia could do it, but it would be very expensive.

HI Sutton’s Shallow Water Submarine is likely a less expensive way to go:


BSmitty July 19, 2021 at 2:27 pm

$9.4B will only buy you ONE Columbia (2018 SAR APUC). Seems like a stupendously expensive way to put ashore half a company of light infantry via rubber craft or scuba with virtually no logistics and minimal heavy weapons.


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