So far in our discussion of Aurora, we've covered everything from the basics of combat up through command structures, but there's one thing that has been overlooked: logistics and the fleet train. Aurora, much like real life, has auxiliaries, and it's time to take a look at how those ships work.

But first, we need to take a look at the logistical needs of the ships. Essentially, a warship has four different things it can run out of: fuel, maintenance supplies (MSP), ammunition, and deployment time. Fuel is self-explanatory. Without it, ships don't move. Maintenance supplies are used to repair stuff that breaks. This normally happens during the build cycle, with the chance depending on the complexity of the ship and the number of engineering spaces, but weapons have a 1% chance of failing every time they fire,¹ and a ship with battle damage can patch itself up with enough MSP. Ammunition, in the form of missiles, obviously gets used up, and it's a good idea to have colliers to support the fleet. And any ship with stays out longer than its rated deployment time suffers from reduced morale, which lowers the accuracy of weapons and increases the time taken to follow orders. Read more...

When one thinks of oceangoing tankers, the obvious cargo is oil, and oil tankers do indeed make up the bulk of liquid-cargo tonnage. But crude oil is far from the only liquid cargo that is transported across the world's oceans, and a surprisingly diverse and interesting fleet of specialized tankers is used to do so.

LPG carrier Victoria Kosan

The most common of these are carriers for various petroleum gases, which are transported in liquid form because this reduces the volume required by factors ranging from 230 to over 600. These products are usually divided into Liquefied Petroleum Gas (LPG), mostly butane and propane, and Liquefied Natural Gas (LNG). LPG can generally be kept liquid at ambient temperature by reasonable pressures, or at ambient pressure at fairly reasonable temperatures. The first LPG carrier, launched in 1931, used pressure, as did most LPG vessels until around 1960, when refrigeration plants began to be more widely used. Today, the system depends on the exact operating economics, with smaller vessels favoring pressure. Read more...

So far in my discussion of combat in Aurora, there's one major aspect I've overlooked: the command system. The game generates officers, and you can make use of them to greatly enhance the efficiency of your fleet.² Each officer has a set of characteristics, bonuses they can give to whatever is under their command. These range from almost universally useful things like crew training (makes the crew better in the long term) and reaction (makes the ship respond faster if surprised) to very niche skills like diplomacy. In practice, you don't have to worry too much about these. If you check automated assignments in the upper right of the commanders window, it will staff your fleet with what it believes is the optimal distribution for your ships. It does a good enough job to not be worth any headaches around micromanagement.

Obviously, your navy will have ranks. All officers entering from the military academy will start at the lowest rank,³ and will be promoted based on a combination of their skills and time in grade. Officers with good bonuses rise quickly, while those who are only good at one obscure thing generally don't. Before version 2.0, the game was set up to make the population of each rank one-third of the population of the one below it, but the current model only promotes when there is a specific vacancy that needs to be filled. When a vacancy opens up, due to retirement⁴ or a promotion in the rank above, the highest-point officer available with a relevant bonus is promoted. Each position has a specific rank, and at least for shipboard commands, only officers of the specified rank are eligible. If someone is promoted while in one of these positions, they are immediately relieved. Read more...

It's time once again for our biweekly Open Thread. Talk about anything you want, so long as it's not culture war.

I recently finished C.S. Forester's The Good Shepard, the novel on which the upcoming movie Greyhound is to be based. (And can I say how annoyed I am that it's going to Apple TV?) Overall, I though it was OK. I didn't like Krause, and suspect that the sort of characters Forester writes will rub me the wrong way in general. But it was a very good portrayal of the problems of command in protecting a convoy early in the war, even if I do think that The Cruel Sea is a better book.

2018 overhauls are Jutland parts four, five, six and seven, So You Want to Build a Modern Navy - Coast Guard Part 1, my history of New Jersey, the review of Alabama, and Falklands Part 3. For 2019, I overhauled the one-part Jutland summary, Battleship Aviation Part 3, A Brief History of the Submarine, Inky's review of the Haifa Naval Museum, Falklands Part 15 and Soviet Battleships Part 1.

It's been quite a while since I looked at the battleships of Russia and the Soviet Union, but it's time I returned to this fascinating and largely-overlooked field. This time, we'll look at the closest the Soviets ever came to actually getting ships into service, the Sovetskii Soiuz class⁵.

The incomplete hull of Sovetskii Soiuz in 1944⁶

Development of what became the Sovetskii Soiuz began in 1935, as Design A, in parallel with the smaller Design B. The initial designs were absolutely ridiculous, with the largest eclipsing even Yamato in tonnage and armed with 16 450mm (17.7") guns. The design actually selected was very slightly more sensible, with 9 460mm (18.1") guns, 32 130mm secondaries, a 450mm belt and a speed of 36 kts, all on 55,000 tons. Actually, it was no more sensible, with more armor and higher speed than Yamato on a smaller hull. This was soon noticed by the people actually responsible for building the ship, who managed to cut speed to 30 kts and the belt to 420mm, still probably too much for the size of the hull. Read more...

Our recent look at missile combat in Aurora has rounded out our examination of the basics of warship design, so it's time to turn our attention to the various systems that I ignored for the sake of simplicity. Some of these are important for individual warships, while others are of more concern to the fleet as a whole.

One of these primarily fleet considerations is passive sensors, which come in two types: thermal and EM. Thermal sensors detect the heat of a ship's drives, while EM sensors primarily pick up the radiation from an enemy's active sensors and shields. Colonies and populations also have EM and thermal signatures, and a major colony can be detected at long range. Passives are far more important for the fleet as a whole than they are for individual ships, and I usually build dedicated scouts which not only operate with the fleet but also gather strategic information on potential enemies. It's also worth fitting any vessel that is likely to operate on its own (such as survey ships) with smaller passive sensors to make sure they aren't completely blindsided by the appearance of hostile aliens. At the very least, you'll know who did it and be able to recognize them if they show up it again. Read more...

In 1815, the series of wars that had lasted more than two decades finally drew to an end. The resulting "Pax Britannica" would last almost a century, although it was not entirely peaceful, and coastal defenses would often find themselves on the front lines. Naval power focused on projecting influence ashore instead of on fleet battles,⁷ both in the wider world as a result of European colonial expansion, and in Europe as a result of changes in strategy driven by new technology. Some countries also focused on coastal defenses as a cheaper alternative to fleet power, most notably the US.

Fort Knox, Maine, a third-system fort⁸

In 1816, Congress authorized a third fortification program, which would prove a marked departure from the First and Second Systems. The Third System was built in the absence of any specific threat, intended instead to provide long-term protection by a well-planned series of fortifications. In keeping with this long-term approach, a board was appointed to designate the locations of fortifications, prioritize them, and supervise planning and construction. As a result, the Third System would be much more coherent than the previous fortification efforts, and many of the results remain standing today. Read more...

As we make our way through Aurora, we've finally reached the point where we can talk about offensive missile warfare. Because offensive missiles require an understanding of how to defend against missiles, I'm going to be relying heavily on the previous parts about defending against missiles with beams and anti-missiles.

The first step to take when using missiles is to decide on a standard size for your offensive missiles. It's possible to run multiple sizes on different types of ships, but I'd recommend against it. That way lies micromanagement madness. On the whole, I'd recommend sticking to missile sizes between 4 and 6. Any missile of size 6 or smaller is picked up by active sensors and fire control at the same point, while larger missiles are picked up further out, so that as a cap maximizes your ability to penetrate defenses. Going smaller means more missiles per salvo, and a shorter interval between salvoes, but less-capable individual missiles. Anything smaller than Size 4 is likely to pay too high a price in capability. Read more...

The Tomahawk missile began life as a strategic weapon, intended to bring nuclear firepower to the Navy's surface ships and submarines. The Navy quickly adapted it as a long-range anti-ship weapon, although the bulk of Tomahawk's impact was made by the second generation of Tomahawks, the Tomahawk Land Attack Missile (TLAM)-C and TLAM-D, equipped with a 1,000 lb conventional warhead and a submunition dispenser respectively. Tomahawk's combat debut against Iraq in 1991 was a triumph, and soon the weapon became a favored instrument of US politicians, thanks to its accuracy and lack of a pilot at risk of being shot down.

An RN Tomahawk in flight

Even as the dust settled from the first Tomahawk strikes in Iraq, a new version, known as Block III, was being tested. The single most important difference from the Block IIs used in Desert Storm was the addition of a high-precision GPS receiver. This removed the various constraints of TERCOM and DSMAC, allowing the missile to be used on targets that hadn't been mapped to within an inch of their lives, and giving targeters more flexibility with routes.⁹ TERCOM and DSMAC remained an option, though, and improvements were made to the later system. Also improved was the warhead on the TLAM-C, with advancing explosives technology allowing it to shrink to 700 lbs, giving space for more fuel and increasing range to around 870 nm (1000 regular miles). Rounding out the package is an improved engine with about 20% more thrust. Besides newly-built Block IIIs, many Block IIs and TASMs were converted to the configuration. Block III also saw the Royal Navy join the Tomahawk program, buying a number of UGM-109s for its submarine force. Read more...

A fair bit of this has been superseded by the changes made in 2.2, which I've written up here and here. If you're new, read this first, then look at those for the current version. Quite a bit has changed here, and I'm not going to do a full rewrite.

Welcome back to my Aurora Tutorial. We're currently discussing combat, specifically warship design. Last time, I covered missile defense with beam weapons, but now it's time to shift to the system I usually base my defenses around: anti-missile missiles (AMMs). AMMs have benefits and drawbacks relative to beam defenses. On one hand, I've generally found them to perform better than beams and to be more effective, particularly in the face of a massed attack. They're also much easier to upgrade, as you can just swap in a new missile with improved performance. On the other hand, AMMs can get expensive, and the ships firing them have limited ammo capacity. If they run through their magazines before the enemy does, you're dead.

So what is an AMM? Like beam defense, AMM defense is a numbers game. You need the smallest feasible missile, fired at the highest possible rate, so the obvious result is a size-1 missile¹⁰ with a strength 1 warhead,¹¹ optimized for the highest hit probability possible and with sufficient range to match the sensor/fire control combination you have planned. As such, you should probably design the electronics first. Missile fire controls are built in the same tab as active sensors, and have the same range characteristics. On average, a typical MFC has about the same range as a search sensor 3 times its size. I usually try for a size 3-4 sensor, and an MFC that either matches it in range or is a little bit better. I do this because I expect later missile defense ships to have better sensors, and a slightly oversized MFC lets the older ship take advantage of the extra range. So going back to the AMMs, a missile's hit probability is equal to (missile speed*maneuverability*0.1)/target speed. Maneuverability is based on how much space you've put into agility¹² so you need to find a balance between spending space on the engine and spending it on agility. Read more...