Nuclear Powered Wessels

[clairobscur]

@mlees

See: List of active French Navy ships - Wikipedia

1 carrier, 4 Boomers, 6 Attack subs, nuclear powered.

I stand corrected.

[GilaB]

I misread the title as “Nuclear Powered Weasels,” which leads to interesting mental images.

I have nothing useful to contribute.

[OtakuLoki]

@robby

The U.S. Navy’s current philosophy is to utilize nuclear propulsion only for submarines and aircraft carriers. Here are some reasons why:

<snip>

2. For a nuclear-powered vessel to be cost-effective, then, there need to be clear advantages for the nuclear-powered vessel when compared to the conventionally-powered alternative.

<snip>

b. For aircraft carriers, the advantage of nuclear power is that it frees up space for storage of jet fuel. The carrier can also be used as a fuel-storage vessel for other vessels in the battle group.

c. For non-carrier surface warships and cargo vessels, the additional expense for nuclear propulsion is not justified by the marginal increase in utility that might be realized.

I think that you’re overstating the costs vs. utility benefit for other surface combatants to be nuclear powered, robby. I think that the utility goes up rather dramatically once one includes missions for surface combatants beyond those that are extensions of the carrier battle group. I still believe that the ability of the nuke cruisers to operate on the end of a very long logistical tail to be worth some higher costs.

Obviously it’s a debatable topic, I just mean to suggest that there are current missions where the marginal utility you mention is more useful than you seem to consider. Not all surface missions are carrier battle group operations, after all. And even when a ship may be attached to a battle group, the specific operational stance may require it to operate independently, far from the logistical train based around the carrier. Which not only puts it in a vulnerable position, but also risks the logistics ships that have to leave the umbrella of the battle group’s protection, too.

[Bookkeeper]

@robby

a. The advantages for submarines should be obvious. A nuclear-powered submarine is freed from having to surface for extended periods of time, and is the only truly “blue-water” submarine. A nuclear-powered submarine could travel at flank (maximum) speed for years without having to surface, only being limited by the endurance of the crew and the amount of food onboard. With no other method of propulsion can you do this, not even with fuel cells.

The USS Triton (SSRN-586) demonstrated this advantage by sailing around the world submerged in 1960 (during its shakedown cruise).

[Tapioca_Dextrin]

In addition to ships and submarines, there were a few other projects to use nuclear powered propulsion. The Convair X-6 and the Tu-119 were two aircraft projects that never really got off the ground, while the Ford Nucleon thankfully never even reached the drawing board.

[Throatwarbler_Mangrove]

And who could forget the delightful Project Pluto, a Mach 3 nuclear powered cruise missile.

@Wiki

The proposed use for nuclear-powered ramjets would be to power a cruise missile, called SLAM, for Supersonic Low Altitude Missile. In order to reach ramjet speed, it would be launched from the ground by a cluster of conventional rocket boosters. Once it reached cruising altitude and was far away from populated areas the nuclear reactor would be turned on. Since nuclear power gave it almost unlimited range, the missile could cruise in circles over the ocean until ordered ‘down to the deck’ for its supersonic dash to targets in the Soviet Union. Once powered up, the unshielded half-gigawatt nuclear reactor would emit highly lethal radiation in a large radius; such a vehicle could not possibly be human-piloted or reused. Indeed, some questioned whether a cruise missile derived from Project Pluto would need a warhead at all; the radiation from its engine, coupled with the shock wave that would be produced by flying at Mach 3 at treetop level, would have left a wide path of destruction wherever it went. The SLAM as proposed would carry a payload of many nuclear weapons to be dropped on multiple targets, making the cruise missile into an unmanned bomber.

[robby]

@OtakuLoki

I think that you’re overstating the costs vs. utility benefit for other surface combatants to be nuclear powered, robby. I think that the utility goes up rather dramatically once one includes missions for surface combatants beyond those that are extensions of the carrier battle group. I still believe that the ability of the nuke cruisers to operate on the end of a very long logistical tail to be worth some higher costs.

Obviously it’s a debatable topic, I just mean to suggest that there are current missions where the marginal utility you mention is more useful than you seem to consider. Not all surface missions are carrier battle group operations, after all. And even when a ship may be attached to a battle group, the specific operational stance may require it to operate independently, far from the logistical train based around the carrier. Which not only puts it in a vulnerable position, but also risks the logistics ships that have to leave the umbrella of the battle group’s protection, too.

Well, up to the present day, the U.S. Navy has agreed that any additional utility provided by nuclear power is not worth the additional cost, which is why the Navy has not built a non-carrier nuclear surface combatant since the USS Arkansas (CGN-41), which was procured in fiscal year 1975, and of course, all of the nuclear cruisers ever built by the U.S. (total of 9) are now retired.

With the increasing cost of oil, however, it appears that this stance is now being reevaluated. Besides freeing a surface combatant up from the need for in-transit refueling, a nuclear-powered surface vessel is not dependent on the availability of foreign oil, which may increasingly become an issue in the coming decades.

There’s a good summary of the issues here in this PDF:
http://ftp.fas.org/sgp/crs/weapons/RL33946.pdf

[Polycarp]

Well, I am very grateful for all the responses, and have been reading with strong interest and having a lot of my questions answered.

[OtakuLoki]

@robby

Well, up to the present day, the U.S. Navy has agreed that any additional utility provided by nuclear power is not worth the additional cost, which is why the Navy has not built a non-carrier nuclear surface combatant since the USS Arkansas (CGN-41), which was procured in fiscal year 1975, and of course, all of the nuclear cruisers ever built by the U.S. (total of 9) are now retired.

This is true.
I think that it’s also worth noting that the latter nuke cruisers, the California and Virginia class ships, lacked the SPY-1 radar and the VLS missile batteries. I was told, while I was in, that they would have been prohibitively expensive to retrofit for those systems which are seen as the backbone of the modern surface fleet’s cruiser and destroyer platforms.

I don’t doubt that the decision to scrap the cruisers was based, in part, on the cost-benefits analysis that you mentioned upthread about nuclear power vs. GT ships. I also have no doubt that the fact that the combat systems of the ships in question were at least one generation older than what is the current standard played a larger part than simply the costs of operation. I also believe that the decommissioning of both California and South Carolina shortly (about four years) after being refueled was at least as much a political decision as the result of any kind of rational cost-benefit analysis.

Thanks for linking that .pdf. I’m intrigued to see that the plan is to go to a single reactor plant for the CG(X) ships. I can see benefits to that plan, and certianly it mirrors the long-standing decision in the US sub fleet that two reactors just aren’t worth the hassles for the benefit. There’s still this voice in the back of my head shouting, “Where’s the redundancy?”

[Elendil_s_Heir]

@Gfactor

Ok. Never Mind. I put it back the way it was.

As you were, Mr. Chekov.

[Hail_Ants]

The US Navy also maintains one nuclear powered, non-combat, research sub, the NR-1…

[danceswithcats]

@GilaB

I misread the title as “Nuclear Powered Weasels,” which leads to interesting mental images.

Don’t confuse them with atomic badgers, which are raced for sport in some parts.

[Cicero]

@Tapioca Dextrin

were two aircraft projects that never really got off the ground, .

In other words they didn’t reach great heights?