This overview answers these questions:
What type of ships can I build?
There are six types of ships you can build:
You can build fast, large fleet carriers for offensive operations, and smaller, slower escort carriers for protecting your own fleets, especially convoys. They can carry fighters and bombers (including torpedo bombers). Aircraft in enough number can sink even the largest ship, and have an unequalled range of attack. But aircraft cannot fly at night or in very poor weather, sometimes cannot locate their target and must break through the enemy’s defensive fighters and anti-aircraft fire before attacking.
Aircraft and especially the pilots to fly them can only be replenished at a certain rate, so you must husband your resources and order offensive carrier operations carefully.
The carriers themselves are also very vulnerable to damage when their aircraft are away on a strike somewhere else.
Nevertheless, carriers became the dominant instrument of naval power in WW2, eventually replacing battleships in all navies that tried them.
Battleships and Battle cruisers
These ships can range from the size of the German "pocket battleship" Graf Spee class of less than 20,000 tonnes through to the biggest naval ships ever conceived – the German "H 43" class monsters of over 120,000 tonnes. Gun calibres can range from 11 through to 20 inches; speeds from 21 through to 33 knots. All ships of this type carry seaplanes that are very useful for aerial reconnaissance; and they can carry large amounts of fuel, giving them a very large cruising range.
Battleships rely on their big guns as the main weapon and often have very heavy armour and a high degree of survivability. Battle cruisers typically mount similar size guns but are faster and more lightly protected, although the German Scharnhorst class sacrificed gun calibre instead of armour. Battle cruisers originated as fast scouts for the main battle fleet and as raiders suited to hit-and-run attacks, alone or in small squadrons. The battle cruiser can be a very powerful attack vessel, suited to bombarding enemy ports and conducting hit and run attacks on enemy convoys and naval squadrons not protected by battleships.
Both battleships and battle cruisers can give tremendous punishment at ranges that make them immune to damage from smaller ships; nonetheless, without a proper escort they are vulnerable to torpedo attack from fast destroyers and submarines, and air attack remains their greatest threat. Though these ships can take a lot of punishment they are not unsinkable, and the loss of (or major damage to) one of them is a critical blow to any navy. Unless the ship is relatively small it will take a long time to launch a replacement or to repair major damage.
These ships make the best scouts: they carry seaplanes for reconnaissance and can carry more, tonne for tonne, than the larger ships; they can carry reasonable amounts of fuel for good cruising ranges and with speeds up to 36 knots (faster than battleships and battle cruisers) and relatively small size they are often able to see without being seen, or to escape unharmed if they are spotted.
But cruisers also fulfil many other roles: from small, fast torpedo-armed cruisers that are effectively enlarged destroyer-leaders, through medium size 6 inch gun cruisers with good range and all-round capability, to larger 8, 10 or even 11 inch gun cruisers, often more heavily armoured and able to be defeated only by battleships or battle cruisers. (In this game, cruisers can carry up to 11 inch guns and range up to 26000 tonnes, so there is some cross-over with the size and capability of small battle cruisers. But the “Cruiser” type is more vulnerable – it will generally have less armour and structural strength, and finer hull lines that allow for more speed but make anti-torpedo defences marginal at best).
A navy will often have between 2 and 4 cruisers (and escort carriers) for every battleship battle cruiser or fleet carrier; the ratio depends on your overall strategy. (See strategies for more information.)
Note that some historical differences are built-in – namely all Japanese cruisers get a torpedo-armament bonus (in terms of a higher number of torpedo reloads).
These do not carry seaplanes so have no aerial reconnaissance capability. But they are the only vessels that can fight submarines or lay mines, and they can carry more torpedoes than cruisers, tonne for tonne. Their fine lines allow them to be the fastest ships in the navy – up to 39 knots. They generally have less cruising range than cruisers and with little or no armour have low survivability. (Being small and quick to build, they are more expendable though).
The "escort" type represents what in reality was a wide range of small-ship types: from slow, small lightly-armed corvettes and sloops used mainly for anti-submarine work, through medium size general-purpose destroyer-escort vessels that were faster and better armed, to very large and fast fleet super-destroyers that were often armed with many torpedoes. While all the historical ships are classed as "General Purpose", in your own designs you can make them specialist mine-laying or minesweeping, torpedo-attack, anti-aircraft or anti-submarine warfare vessels. They will then have increased capability in the chosen area and reduced capability for other functions.
A navy will often have between 8 and 16 escort ships for every battleship, battle cruiser or fleet carrier; the ratio depends on your overall strategy. (See strategies for more information.)
Note that some historical differences are built-in – namely all Japanese escort vessels above size “2” get a torpedo-armament bonus (in terms of a higher number of torpedo reloads).
In this game, each country has two basic historical types – a small sea and coastal-going type, and a larger ocean-going type. But you can design your own to a much greater variety of characteristics. Submarines do not carry seaplanes, so they will often rely on being guided to enemy fleet locations from fleet sightings picked up by other forces or signal intercepts.
They have good cruising endurance for their size and can only be attacked if they themselves launch an attack. Their survivability is generally low but can be improved through higher underwater speeds, stronger hulls and of course better training!
Merchant ships carry cargo (raw materials or finished suplies), and cargo-carrying to your home and advanced ports is the major way of improving your resource position, so merchant ships are vital to your success. They are slow and have low survivability when damaged, so defence of them against enemy submarine, surface and air attack will be a major part of your operational plans. Unlike the naval vessels mentioned above, merchant ships are powered by diesel machinery for which oil fuel is plentiful; it is assumed they can easily carry enough for even the longest voyages, so running out of fuel is never a factor for merchant ships whereas it is a major factor for naval vessels.
Merchant ships can also carry troops.
Each turn, if you have enough resource points at your Home Port, you can lay down new ships.
One resource point can be used to construct 100 tonnes of shipping, so a medium size 45,000 tonne battleship like the South Dakota will require 450 points.
How long do they take to build?
On the first turn, unless their commissioning has been delayed, these ships become immediately available but on subsequent turns they take a realistic amount of time to build: big battleships may take 2-3 years or even longer. Escort ships may take up to a year, Cruisers perhaps 1 to 2 years. The construction rate for naval ships depends on the ship tonnage and your Home Port Docks efficiency. (See dockyard infrastructure for more information).
Merchant ships are of course much quicker to build than naval ships.
If this option has been enabled in game options you can freely create your own ship designs. For example, you can design battleships up to 130,000 tonnes in size - nearly twice the size of the Japanese Yamato class and equal to the biggest battleships ever conceived (by Germany, as part of its "Z Plan".)
See building ships for more information.
Designing ships (or selecting suitable designs) is a critical part of SAS because you only get real value from your ships when their design matches their intended role.
In WW2, each country tried out many different designs of each type of ship, always striving for the best combination of speed, range, armour, gun power and so on for the size of ship they could afford and the kind of role they wanted the ship to perform.
For example, a battleship suited to fast hit-and-run missions – such as the German Scharnhorst - should (and did) look very different to one suited for purely defensive escort work - like the British Nelson - even though their tonnage was rather similar.
As the Supreme Naval Commander, you take advice from your Director of Naval Construction, but the final decision is always yours to make.