It's time once again for our open thread. As usual, talk about whatever you want, so long as it isn't culture war.
I had a great time two weeks ago on the Iowa, and thought I would post this photo of those who showed up.
John Schilling, Randy M, me and CatCube
2018 overhauls are Ship History Missouri Part 1, So You Want to Build a Modern Navy - Coast Guard Part 2, The QF Gun, Yalu River, DismalPseudoscience's review of Mikasa and German Battleships in WWII. 2019 overhauls are Signalling Parts two, three and four, The Pepsi Fleet?, Falklands Part 16 and Pictures - Iowa Communications. 2020 overhauls are The Last Sailing Battle, Naval Rations Part 2 and Part 3 and Nuclear Weapons at Sea - Light Attack Parts one and two,
Comments
I like the comment about German Battleships of WWII where people debate who sank the Bismarck. By that silly logic, the Japanese won the Battle of Midway because the Yorktown was sunk only by the Japanese, where the Kaga, Akagi, Hiryu, and Soryu were all scuttled after being gutted by the likes of Dick Best.
Not sure what your stance is on your personal privacy, but you should consider blurring your pass.
Interesting. Didn't think of that. I'm not that hard to de-anonymize, but I do try to make it at least moderately inconvenient. I've blurred it out.
The four of you look just as I had pictured you. Yep, exactly. Yessirreebob.
First .. thanks for the blog you're awesome.
Second .. the very last flight of the S-3 Viking was on July 13th this year. Sadness.
I must decide to visit my brother in Pasadena, and add a battleship shaped notch to my belt...
So I am rereading 'Ignition'. One project jumped out at me, the "Ultra High Density Propellant Concept". We can extend the range of a rocket by 40% by replacing 20% of the fuel with mercury for extra reaction mass.
That'll kill your Isp though.
Apparently it was more practical than trying to test Me2Hg as a fuel.
Eastman Kodak screamed at him when he tried to order a railroad car of the stuff.
I never thought I'd see a more daft idea than zip fuel, but here we are.
Lambert:
For high Δv missions a very bad thing but this was aimed at Δv << vₑ and quite possibly more volume than mass limited.
They tested the Hg injection system out in the California desert. It worked exactly as calculated, and probably didn't poison too many rattlesnakes. So, in that respect it comes out ahead of the 'billion buck boron boo-boo' (as the book calls it)
Speaking of bad ideas, 90% N2H4 + 10% HCN solves the problem of your hydrazine iceing up.
Dimethylmecury? That'll kill far more than your Isp.
And that book was written before the death of Karen Wetterhahn, who got a couple of drops of the stuff on her lab gloves.
In fairness to Dimethylmecury, it took several months to kill the Dartmouth-girl. Then again, "You will be fine for months then fall over dead without warning" is kind of scary in its own way.
But, yeah, metallic mercury injection was clearly the safer design.
Yeah, I didn't quite get the point of the high density chapter in that book. It was just to get more thrust per fuel tank volume wasn't it?
If we're talking about dangerous propellants, I have to recommend "A Tall Tail", a short story by Charles Stross, online here. The use of mercury-based fuels turns up about halfway through, and it keeps getting worse from there.
@Doctorpat: More propulsive impulse per unit fuel tank volume or more thrust per unit fuel pump power. Since most (liquid) rocket engines are dominated by the fuel pump and associated plumbing, and many rocket vehicles are dominated by the fuel tanks, these can be important considerations. Or sometimes not, e.g. in-space propulsion where you can accept lower thrust and fuel tanks are only a small proportion of your dry mass.
There are also applications where you are limited to a previously-established volumetric envelope but now you want to increase the performance. E.g. Tartar was designed to shoot down airplanes 30 km away, VLS cells were designed to hold Tartar-derived missiles, now we want to shoot down ICBMs with something that fits in a VLS cell. Or use them to launch cruise missiles that can hit Moscow from the North Sea, and yes, we did formulate special high-density replacements for kerosene for that.
Ignition! is amazing and a book I can heartily recommend.
(I did recommend it to a friend who worked at Picatinny Arsenal, which merely confirmed their desire to never drink the water from the on-site system)
@Ian - in that case dont let him ever read Max Gergel’s “Excuse me sir, would you like to buy a kilo of Isopropyl Bromide?” also available at http://www.sciencemadness.org/library/
As I understand it from various online searches, the old lab site is still classed as contaminated land surrounded by a chain link fence.
Unless it's at Picatinny, doesn't matter ;)
ike:
Not really, Boranes don't seem to have done any worse and on the whole are probably a good deal more useful (are they and fluorine containing oxidizers really any worse than N₂O₄ and various Hydrazines?).
ike:
So does adding a methyl group or two.
Are there even any storable missiles that use flouro-oxiders?
Boranes' tendency to foul the engine (making it explode) with any other oxidizer, in my mind, makes them impractical.
But now I'm reading that with interest
I don't think there are any rocket engines which have used fluorine operationally, either now or in the past. You can store fluorine, so long as you make sure to get a fluoride film on the metal, but one scratch and things go very wrong.
I was think more about ClF3, ClF5, FClO3, &c... all of which are way spunkier than plane-Jane F2.
It's not just scratches that cause explosions. Greasy finger-prints work too. Gaskets too! The whole thing will need to be welded at every joint. Slang-inclusions will explode, too. It's just FUN, FUN, FUN all the way down.
Yes. I first read Ignition while I was in college, and know all the fluorine stories. The best propellant story I know that isn't in there belongs to John, and I guess I'll use this as the place to ask him. But I don't know of any operational use of any oxidizer where fluorine is a major component, whatever it may be. (No, IFRNA doesn't count.) I really want to see a ClF5 rocket used, but only if I'm not filling out the environmental paperwork.
@Doctor Pat
On a previous Open Thread we were discussing the fighting that took place in WW2 in New Guinea and the almost incomprehensibly rough conditions the forces faced--in addition to a determined enemy.
While surfing around I ran across an Australian movie called called Kokoda that dealt with the "Chocos" who faced the initial Japanese forays southward on and around the Kokoda Track.
The movie itself was the usual bit of green troops facing tough odds, personality conflicts, loss off some of the unit, fierce enemy, etc., but on occasion the director took vista shots that showed the jungle and the terrain. It was awe-inspiring to say the least. It looked to be a trek I would only tackle on a good day, with good kit, and an experienced guide.
Astounding that they were actually fighting there with all the heat, intestinal disorders, jungle rot, disease, lack of adequate kit and munitions, and on and on.
Fortunately there were subtitles so I could follow the Oz dialog!
2.5 stars out of 5 for the actual movie, but 5 stars for the glimpses of what it must be like in that region.
Why would the ClF5 paperwork be any worse than HF? (It's all going be that in a moment, regardless of what happens) Or am I underestimating environmental paperwork?
@Neal,
Apparently the Kokoda track is now all "gentrified". You book a trip, pay for a guide, stay in guest houses built along the way. They've probably even put in some work to do guide rails and foot bridges over the rivers.
When I went it was a lot more raw. You caught a bus, (chickens and all), told the driver to stop at the appropriate spot. Wandered around until you found a wooden sign telling you this was the track start, and you set off. Camping by the side of the path. Having forks and loops and misleading multiple choices in the path, because the locals use it to do their own transport between their own villages.
@ike
Amount. The HF in IFRNA is 0.6%, so it's rather drowned out by everything else around it. I also suspect that the Fluorine finds something appropriate to bond with and happily sits there for the rest of time. Not a big deal when you're spraying nitrogen oxides everywhere. This is much less of the case when fluorine is a major component.
Also, nobody in the US uses IFRNA any more, certainly not for first stages. The military vastly prefers solids for obvious reasons, and western boosters are all LOX.
ike:
Making the engine big enough and being careful with injector design seems to work at preventing that. But if you're using something as dangerous as borane may as well use some fluorine as well and get the extra performance.
ike:
A fluoropolymer should be able to not explode.
bean:
What environmental paperwork?
Speakng of contamination, they used to make a lot of arsenic-based insecticides round these parts. Now all that land's been turned into luxury riverside apartments. It's been throughly remediated but I'd still rather not live there.
"A fluoropolymer should be able to not explode."
Nature is one step ahead of you. : ) They are safe from chemical attack from ClF3, but are soluble.
None of the fluorinated oxidizers (or boronated fuels) were ever used operationally that I am aware of, though there may have been e.g. some classified Soviet program that was thoroughly buried at the end of the Cold War. And maybe that's what the Nazi flying saucers operating out of Antarctica used :-)
As for the worst propellant combination ever, the one that didn't make it into "Ignition" because death mercifully claimed John Drury Clark before he could learn of it, I give you NA7.
https://en.wikipedia.org/wiki/Nitrousoxidefuel_blend
A 7:1 mixture of nitrous oxide and acetylene, intended for use as a monopropellant. And a wondrous propellant it would be, with a specific impulse equal to the best non-cryogenic bipropellants but self-pressurizing and with only a single set of plumbing. Except for the one wonderfully understated line "A 2008 AIAA paper on the decomposition of nitrous oxide has raised concerns about the safety risks of mixing hydrocarbons with nitrous oxide. By adding hydrocarbons, the energy barrier to an explosive decomposition event is lowered significantly"
And Bean's old Boeing buddies wanted to use that in an air-launched satellite launch vehicle, with about three tons of the stuff hanging under an F-15E in a supersonic zoom climb.
It wasn't quite as insane as it seems. Nitrous oxide has a reputation as a safe(ish) oxidizer, because it jealously clings to that one oxygen and only reveals its oxidizing nature at high temperature. And acetylene, while roughly as user-friendly as nitroglycerine in its pure form, is dangerous mainly because acetylene molecules seem to really hate other acetylene molecules. There's a long history of safe industrial use by storing it as a dilute solution in some inert solvent, typically acetone. If nitrous oxide at low temperatures was sufficiently inert, NA7 might have been as safe as the acetylene tanks any schmuck can rent from their local welding supply shop.
Worth a try, at least. And they tried, with me looking over their shoulder to make sure they didn't kill anyone. It worked surprisingly well in safety and cold-flow tests, if you were careful to follow the rules we set up. You could mishandle the stuff pretty egregiously, or run it through complex plumbing and rocket injectors at many gallons per second and 1000+ psia, and it was as nice and friendly as, say, air-conditioning refrigerant.
Until you tried to ignite it. In which case ignition transitioned to detonation, every single time. The detonation propagated through injector orifices maybe a hundredth of an inch wide, through any flame arrestor anyone could figure out how to make, all the way through the propellant and into the run tank. I distinctly remember from one test report, the phrase "small fragments of the container not exceeding three millimeters in size, were recovered from the surrounding desert".
At least the reaction products weren't toxic. But the program was quite thoroughly cancelled: https://spacenews.com/darpa-airborne-launcher-effort-falters/
The phrase 'monopropellant' always scares me.
I guess there isn't much difference between 'monopropellant tank' and 'bomb'.
The best monopropellant is as yet mainly theoretical. Under insanely high pressures, hydrogen becomes a very dense liquid metal. When transitioning back to gaseous H2, it releases an insane amount of energy, enough for a theoretical ISP of 1700s. For comparison, the theoretical max is 460s for conventional hydrox rockets, with practical ISPs of around 370s at sea level and about 450s in a vaccine. Practical ISPs from experimental nuclear-thermal rockets have been around 1000s.
As an added plus, if liquid metallic hydrogen can be stored at all (see below) it should be much better behaved as a rocket propellant than cryogenic liquid H2. The big downsides of H2 as a propellant are it's ridiculously low storage temperature, its extremely low density, and its tendency to leak out through everything. LMH is slightly denser than water and probably doesn't need cryogenic storage temperatures. I don't know if it's any better in terms of permeability, though.
The tricky parts are:
Only microscopic amounts of liquid metallic hydrogen have been produced in labs. There's no technique for making it in quantity, short of strip-mining naturally occurring LMH from Jupiter's hydrosphere.
Whether or not LMH is stable enough to be stored in quantity at reasonable pressures without spontaneously releasing all it's energy and turning back into H2 is an unsolved research problem. There are theoretical results that suggest it could be, but they're yet to be confirmed.
LMH burns hot enough to vaporize titanium, which makes rocket engine design for it a little tricky. You'd need to either somehow design an engine to withstand the temperatures, or you'd need to water down the LMH with a relatively inert admixture.
Yeah, H2 is a real SoB from a storage prospective. To it, even steel is like an onion sack.
1st Sea Lord wants to bring LORAN back, in case GPS gets shot out of the sky.
https://www.bbc.co.uk/news/uk-politics-57440787
I saw this post on USNI blog and figured it might make for some interesting conversation (i.e. it's some nice juicy red meat). A taste:
I still think my favorite fact about those unforgivably backward-looking old dinosaurs of the "Gun-Club" era navy was that the General Board stated it's ideal was 1 carrier per BB division... in the early 1920s.
Well that'll teach me to post without proofreading...
So I was reading an article on the deployment of the HMS Queen Elizabeth as she deploys to the South China Sea, and while continuing to wonder at the weirdness of her escort/airwing arrangments, my eye was caught by the picture of her transiting the Suez Canal and I had a dirty thought.....we don't let 7th fleet transit the Suez do we (images of the Evergiven flash to mind)?
@Directrix Gazer
Well put. It always gives me a warm, fuzzy feeling to see something like that and think "Yes, I have already written up responses to the points in question". I also looked at the main article, and particularly liked the bit where he said that submarines would make aerial refueling impractical in a war with China. I don't have a blog post answering that.
I think the best single-volume corrective for the many persistent myths about changes to military technology and doctrine between the world wars is Military Innovation in the Interwar Period. Maybe I should mail a copy to Ensign Brenza.
That looks interesting. If you're sending copies to people...
(More seriously, I've added it to my Amazon list.)
Annoyingly, I cannot find the "Add to List" button on the product page - not even when I to search for the text (but searching "add to" finds two buttons that allow me to "Add to Cart" and one to "Add to Book Club"). Upon further investigation, I also don't see an "Add to List" button for either of the "often bought with this" books; but other items in my browsing history DO have the button on their pages, right where it's always been.
I predict ENS Brenza will have a difficult first tour.
bean:
But I want my Aegis submarine.
Does this mean that midair refueling FROM a submarine would be impractical? Because I could buy that.
@Dr.Pat
You would probably need dedicated oversized UNREP-subs.
ike
Very FAST UNREP-subs. Unless doing a UNREP of a helicopter I suppose.
@Dr.Pat
There is something charming about the idea of the DoD trying to bend bomber stall-speed and submarine cruise-speed until they match.
I guess you could drop a hose from a harrier in hover-mode to a normal submarine. I wonder how big the hose would have to be to keep ahead of the game.
Simple question with maybe not so simple an answer: how close would Iowa have to be to another battleship (let's say something about the size of Bismarck) in order for her guns to have a >50% probability of hitting the target. Assume both Iowa and the other ship are steaming at a constant bearing and speed (i.e. no zig-zagging), and that the weather is clear.
Doctorpat:
Update the F2Y, might not actually be in-flight refueling but it'll be close enough.
ike:
Probably not all that big, airliners don't seem to take too long to refuel.
@quanticle
I think Bean has said before that the RADAR-FC was good enough to get first shot straddles. So it becomes pattern-size over ship footprint. (Do those calculations in phi-theta space for maximum accuracy)
My gut feeling is that it works out to something like 20-30% of max range.
@ike
So if you want to refuel a non-VTOL aircraft, the Harrier picks up fuel from the submarine, then switches to forward flight and passes it on through conventional mid-air refueling. Simple as.
@DampOctopus
I REALLY want to call that idea stupid, but the British did way worse in the Argentine War and had it work out.
If it is stupid, and it works, then...
I think an Osprey would make more sense than a Harrier, but yes, otherwise there's no way to refuel an airplane from a sub. Unless it's a seaplane, because they did that.
Also, re the Osprey, the Navy is doing the first deployment of the CMV-22 soon, and I just wanted to register how much I absolutely loathe that designation. Like, I get why the Marines have the MV-22 and the USAF the CV-22, because they were paranoid about someone getting the CV-22 confused with a carrier. Fair enough. But to then go for CMV-22 instead of UV-22 makes no sense at all. We have options for a reason, and you should not create hideous frankenstein designations just because you can't be bothered to think.
Counterpoint: our naming and ship-designation experiences over the last 20 years.
Chalk up your hands and throw another set of 45s on the bench to prepare yourself for the SWOLE Act
The problem with refueling Harrier in the hover wouldn't be giving it fuel faster than the engine can burn the stuff off, as current aerial refueling methods manage to do that plenty well enough. The problem would be exceeding the Harrier's max weight in the hover, especially if you're trying to give it enough gas to act as a buddy tanker. Even if you're just supporting the Harrier itself, and not trying to use the Harrier as a buddy tanker for something more capable, it won't be able to take on enough fuel in the hover to operate for very long if it's also carrying any other payload. It's just not a good choice.
@quanticle,
Are you looking for the range at which an Iowa has a >50% chance of scoring when firing a salvo, or are you looking for the range at which there's a >50% chance of hit per gun fired? Radar FC with all the bells and whistles pushes the former out pretty far, largely independent of weather and relative motion (see Iowa's first-salvo straddle of Nowaki at Truk in Feb 1944, at a range of 37,500 yards). The latter I'm not certain of, but to get 5+ hits per 9-gun salvo I suspect it would have to be very, very close.
@Philistine:
Eh, I bet it would be, though. I know HIFR is an unpleasant option for helicopters, largely because they burn so much fuel doing it that it takes forever. I'd expect a Harrier in the hover to burn even more than that. Plus you burn more fuel at lower altitudes (due to air density, IIRC? I dunno, I was a fake engineer).
For battleship gun accuracy, graph 1 at http://www.navweaps.com/indexinro/INROBB-Gunnery.php suggests USN 16" guns were scoring 50% hits on battleship-sized targets out to 10,000 yards in 1940-41 exercises. Subsequent improvements in fire control during the war would mostly increase the likelihood of achieving that performance in actual combat, i.e. getting first-salvo straddles by radar, rather than improving the maximum achievable accuracy. That was set by ballistic dispersion, particularly variation in muzzle velocity, and I don't think there were any improvements in the 1940-1945 timeframe on that front.
Bean can tell us whether there were any postwar tricks that would have resulted in improved performance in the hypothetical (and silly) Iowa-vs-Kirov duel.
I believe pattern sizes did fall somewhat during the 1980s. After New Jersey's famously bad performance in Beirut, they repacked all the powder to reduce variation in muzzle velocity, which brought it below WWII values. During the battleship era, the USN didn't optimize for low pattern sizes because they thought that past a certain point, a small pattern was actually less likely to deliver hits because of errors in mean point of impact. I know several cases where one side thought the other would have done better with looser patterns, so they were probably correct. This was less of a concern in the 80s for obvious reasons.
The sailor the Navy accuses of setting the BHR fire has been (inadvertently?) identified.
It's early, but so far this is giving me big IOWA investigation vibes.
bean:
The USS Independence was CV-22 for a brief time but was changed to CVL-22 and sunk in 1951, how could anyone possibly confuse an in-service tiltrotor with it?
Blackshoe:
True, but that doesn't mean screwing up another one is a good thing.
Philistine:
The submarine doesn't have to stay still, if it can do 20 knots on the surface that should give some aerodynamic lift.
An optimum submarine for refueling hovering aircraft might be optimized more for surface performance than subsurface possibly resulting in a configuration more like a WWII submarine than a modern one.
John Schilling's numbers were 25% of max gun range. My gut was victorious!
@Blackshoe,
That's a good point. Normally mid-air refueling would be done at cruising speeds, with the engine in a much less thirsty regime; hovering requires the throttle to be wide open. Still, though, current mid-air refueling techniques also allow for fairly fast tanking of much larger aircraft than the Harrier so... Maybe?
@Anonymous,
I don't think 20 knots of forward speed would generate enough aerodynamic lift to matter - not for a stub-winged little brick like the Harrier. Even with thrust vectoring, Harriers need to get up to 65 knots before attempting short take-off with any useful payload.
Now, if this hypothetical UNREP sub were to be built with a flight deck, and perhaps even a ski jump, then we might be in business! You know. Since we're going nuts on the sub's hull design anyway.
The nature of warfare is that every so often someone reinvents Ace Combat: https://acecombat.fandom.com/wiki/Alicorn