What kind of navy could island nations with populations in the few 100k range build to fight each other in a 1890s-1920s naval technology?

Question

There are several small island nations with populations between about 100 thousand and one million people. They each have one or two central islands with a significant amount of small outlying islands. They are industrialized and have GDPs per capita compared to wealthier industrial European economies of the period, but their economies are obviously limited by their populations and land area.

They are in the era of the 1890s to early 1920s technologically, and are significantly concerned about the prospect of going to war with each other. They know they could not win against any major naval power, so they are largely focused on war with each other. Their major concerns are a mix wars aiming to take a limited amount of territory from others or complete conquest, although notably while some wars aiming to take pieces of territory occur no larger scale attempts at complete conquest actually happen but they continue to remain a concern.

They are willing to sink a large amount of their economy into constructions of their military and there is a serious prospect of war between them. As they are all island nations, their navies are their primary concern. They have access to the full range of naval technology they can afford.

While towards the later part of this time frame air forces come into existence due to the era they have limited payloads and short range (aside from airships) while still being quite expensive, The islands are spread far enough apart that while aircraft could be used as a defensive asset they are not relevant as an offensive asset.

Under these conditions what kind of navies would be most effective for them to build to fight each other?

Answer 1

Trying to collate some of my comments into an answer.

None of your countries builds warships themselves. The great powers of your world have more experience, better R&D, and better economies of scale, and probably don't have to import so much material. Even if your countries have the industrial capability to build warships, it's more efficient for them to purchase from a major power and use their industry in other ways. You can observe this in real world navies, both at the time in question and the present day.

What ships would they have - probably no dreadnoughts. Your bigger ~1M countries probably have a few destroyers, perhaps even a couple armored cruisers, and yes, landing craft (which they might build themselves) as noted by Richard Kirk. Your smaller ~100K countries are unlikely to be attempting invasions, their focus is on not getting eaten. That means they go for torpedo boats, possibly submarines, minefields, shore batteries - everything to make it too painful for a bigger country to land an invasion force. See the Russo-Japanese war for contemporary real-world battles and effectiveness of torpedo boats even against bigger ships.

Regarding submarines - your bigger countries probably have a few, they may be too expensive to operate for your smaller countries (even if they theoretically could, what's better - one or two subs, or several more torpedo boats?). Anti-submarine warfare until the second half of the First World War was basically "hope to catch them on the surface and sink them with guns", depth charges and hydrophones developed slowly enough that the first submerged U-Boat wasn't sunk until 1916. Now that's technically still in your time period, but near the end and your countries aren't first-rate powers, so most likely they don't have access to anti-submarine technology and are still trying to catch them on the surface (early subs can't stay underwater very long yet, so this isn't as hopeless as it sounds).

Incidentally, although older ships continued in service, which means we can attempt an answer, there's a huge difference in naval technology between 1890 and 1920, I'm not sure you could pick a 30-year period with more development. If we take the start of this period then nobody is using submarines yet, although a few countries are actively developing them.

Edit: as vsz noted, they may prefer to purchase older ships at a discount or even accept them as "gifts" in exchange for some favours, but they can also probably commission some new ships - consider the naval arms race between Brazil-Argentina-Chile during this era. Those countries are all a few times bigger than your biggest ones but also less developed than you seemingly want yours to be, so the budget difference may not be that big, and your countries probably won't be ordering some of the bigger ships anyway.

Answer 2

How about...

• Landing craft

If you are going to war with an island state, you are wanting to occupy their island. This will have to be done by the army. These may need an escort. Can be re-purposed civilian craft, such as the Roll-on-roll-off ferries I the Falklands war.

• Buy second-hand cruiser from major powers.

This will offer no significant threat to the major powers, but this will probably be better than an island nation could build for themselves unless they have coal and iron ore.

• Submarines.

A popular option for the naval underdog. See for example The Fenian Ram - a submarine developed by Irish nationalists in 1881 for use against the British, the German 'U' boats of WWI and II, and the Italian Caproni CB class. Can sink many times their own weight of enemy ships. Also useful as an escort for landing craft.

• Torpedo Boats

Suggested in the comments, and added here. Good for island defence and short-range escort duty.

Answer 3

Many would have difficulty building more than one or two war ships.

They could certainly sustain some fishing boats or smaller wooden boats for warfare, but 100k people isn't enough to sustain a shipping industry. The larger nations could perhaps build one easily, or ten or so by devoting everything to it.

Britain had 400 million people backing it, and vast tax reserves from them, and had around 400 ships in 1900s. A million people per ship. That was using 10% of their military budget. Each of these nations have a tenth of the people.

If these smaller nations use 100% of their budget and have higher taxation they might be able to build one or two battlecruisers. They could surround these with numerous converted civilian ships with cannons and rifles. The battlecruisers would act as fast and deadly ships which could easily sweep up fleets of enemy ships and control islands, while the other ships would harass and scout as needed.

The larger nations would have a massive advantage of course, and be able to crush smaller nations. The battlecruisers would at least mean they could compete. The range of torpedos and smaller artillery is lower back at that tech level, so outside of mist and ambush, larger ships have a huge advantage. The smaller nations would need to rely on heavily fortified coastal bases and radio communication and alliances to survive larger nations, and pool their ships for attacks.

Answer 4

Numbers by analogy.

For numbers, look at Albania in 1930, swap the importance of the army and the navy, and divide it by three or so for population sizes. That would give you perhaps 4,000 naval personnel on active duty. Scaling proportionally, 60 smallish boats. Or 30 smallish boats, 3 to 5 small ships. The price to pay is that there will be fewer ground forces. (Just a citizen milita, or a regular battalion as well? Maybe a few coastal artillery batteries.)

What were navies like in 1900 or 1920?

The time period is historically split by WWI and included much of the arms race before it.

1900 to 1910

Steam turbines were the great new thing, both in torpedo boat destroyers and in dreadnoughts. The performance of torpedoes was iffy, unless fired from a perfect ambush position. Gunnery ranges were limited by targeting and training. Navies did include:

• Dreadnoughts and pre-dreadnought battleships. Big guns (same caliber in dreadnoughts, different caliber in pre-dreadnoughts) Obviously much too expensive and too large for your islands.
• Armored cruisers. These were smaller than dreadnoughts, but otherwise similar. They could fight anything less than an armored cruiser and win.
• Protected cruisers. These had no side armor, just well-placed coal bunkers to give some protection. Cheaper and easier to build than armored cruisers.
• Gunboats and sloops. Generally unarmored, with deck guns. Might still carry sails in addition to steam. These were used to 'police' colonial empires.
• Torpedo boat destroyers. Smaller than a sloop, faster, armed with torpedoes and a few small cannon. They would support the own battle line against enemy torpedo boats, or attack the enemy battle line.
• Torpedo boats. Slower and smaller than destroyers, with just a few torpedoes and perhaps a little gun or two.
• Monitors. Coastal or river craft with significant armor for their size and very big guns for their size.

My expectation would be some of the lower-end gunboats and sloops, and perhaps some torpedo boats or monitors. Consider these:

• SMS Iltis, a German gunboat.
• HMS Calypso, a British corvette, or perhaps something slightly smaller.
• SMS Graf Geotzen, a German gunboat on a lake in Africa.
• SMS Körös, an Austrian river monitor.

Except for the monitor, what you see there are ships a little bit faster than freighters of the same era, with a few deck guns and machine guns.

Say two or three of these as the "main" force. Having just one would be dangerous, in case it needs an overhaul, but the crew might be insufficient to man all at full strength, and ammo might be in short supply. Two or three armed freighters with room to carry a few companies of troops. Plus a few basically civilian craft with a few small guns.

1920ish

Bigger and better cruisers and battleships, aircraft carriers and submarines are probably bayond the reach of your nations. A tiny submarine like the German-Finnish Vesikko might be a "wonder weapon," but more likely it would be a "white elephant." Some motor gun boats might augment the flotilla.

Or perhaps they might reallocate some of their naval budget to shore-based, fixed-wing aviation. A dozen little biplanes, with wheels or floats, like the Fairey III or the Sopwith Cuckoo. This would not draw much of the manpower pool, but perhaps too many funds to be practical.

Answer 5

In 1900 the nation closest to have 100k inhabitants was Luxembourg, counting 250k.

Italy, which was not a naval power but only had the ambition to become one, counted 33 million.

The British Empire, which was THE naval power at the time, counted 400 million.

With such a limited population and economic base, their only option is either guerrilla or piracy targeting commercial routes, not a real naval warfare. Alternatively, they could try getting alliances with stronger navy nation and have them fight in their place.

Answer 6

Populations in the 100ks? Lets talk about army sizes...

Full mobilization of the US during WW2 had 7% of the population serving in the military. And that took a couple of years to achieve and took a long time to recover from. So its not practical for a nation to remain at full mobilization for a long period of time.

During peace time/not full blown war. It has been closer 0.3% of the population serving in the military. So the core of each your island nations will be that 0.3% multiply that by a population of 100k and you get a grand army of 300.

That's not enough to man 1 large warship. Most likely your island nations peace time navy is going to look a lot like the US coast guard. Primary purpose will be pollicing national waters looking for people fishing without permits/smugglers. In other words, your peace time army doesn't have experience with naval warfare, and the quickly trained war time army (IE poorly trained) will be less skilled then that.

To be a little hyperbolic, your islands nations experience with warfare is a bunch of rude words between one patrol boat and another. As it is doubtful that our island nations could afford to arm their patrol ships with rocks to chuck at the other guys.

Answer 7

Tiny Nations need tiny warships

As other answers have pointed out, these island nations will not be able to maintain a military of more than about 300-3000 total fighting men, and most of those soldiers will likely be army; so, I'd expect a total available force of 100-1000 men. It is technically possible for these islanders to aquire large warships from other nations, but manning them is a whole other problem. WWII warships had an average crew size of 350-3500 men. The problem here is that 0-3 destroyers gives your navy very little coverage. Islands have a lot more coastline for thier populations than full larger nations meaning that if they invested in the large warships used by the larger nations, the enemy would have a lot of opportunity to just go around your destroyers because they could not possibly secure the whole coastline.

Instead they would focus on small gunships like the French 1915 class river gunships. These smaller warships were more like floating tanks than destroyers. They'd only have 1-2 cannons, thick armor (for thier size), and maybe a few guys on the deck to support with machine guns. Instead of needing hundreds of crewmen, these ships could be fully crewed by 20ish men and at only a fraction of he cost of the bigger ships. So, instead of 3 or less destroyers, your island nations could field 5-50 of these smaller ships giving them enough spread to defend thier shoreline.

At most I would expect the larger islands to have a single second hand destroyer to server as a flagship, but even the bigger islands will mostly use gunboats.

French Brutale B1915 Gunboat

Answer 8

Older cruisers and destroyers bought at discount from major powers

If not only the technology, but also geopolitics are similar to the real world historical era, then these nations would be in the sphere of influence of major powers. And if they are both independent and consider going to war with each other, it means they are not fully under the hegemony of one of the major powers, but as the major powers will want to exert some influence in the area, they will use these nations either in proxy wars, or as a projection of power.

As other answers explained, these nations are too small to be able to construct capital ships of the era. However, they could purchase second-rate ships from the major powers. When a major power upgrades the fleet, it will sell some of the older vessels to them. This might even happen at a serious discount, and some vessels might even be gifted, so that the donor Great Power can increase its influence in the area by strengthening its local ally/protectorate.

These nations will then likely end up in the sphere of influence of one major power or another, and the wars between each other might even be proxy wars between the major powers.

What kinds of ships could they have? Take a look at the SMS Emden, which would have been a relatively minor vessel in a battle like the Battle of Jutland, but in East Asia it alone had a really serious effect, and achieved impressive results. So, in an archipelago far from the mainlands of the major powers, an armored cruiser would fill the role of a capital ship, with a couple light or protected cruisers, and up to at most a dozen small destroyers for the bigger nations (here I mean something like the 1893 Daring-class, or the 1903 River-class at most, not giants like the Fletcher) completing the fleet. They would be far too much for them to build, but acquiring such a fleet might be possible by buying (or receiving as "gifts" in exchange for exclusive trade deals) older ships from the major powers. Then they can complement this fleet with torpedo boats of their own design, which is the only naval vessel they could realistically build themselves.

An interesting example at a smaller scale.

The novel Mathias Sandorf from Jules Verne features an interesting example for a navy of a small island nation. The protagonist founded a small nation on a previously uninhabited and recently purchased private island in the Mediterranean, close to the African coast, in the late 19th century, which gets under attack by pirates organized by the Senusiyya movement. The island's population is only in the few thousands, but as they are fresh settlers, most of them are of military age, and they can muster a defending force of about 500 men.

The islanders have a modern 350-ton steam yacht as their flagship, which was made to order in France, equipped with Hotchkiss revolving cannons, and three small semi-submersible fast torpedo boats of their own design. The attackers have the numerical superiority, coming with a huge fleet mostly composed of small sailing ships, fishing vessels, with a few larger but poorly armed merchant ships, carrying a large landing force to conquer the island. The navy of the defenders cannot stop them entirely from landing troops, but does enough damage to the invading navy that the greatly diminished landing force is finally defeated.

This is a great example of what a small but technologically very advanced island nation can afford: a relatively big ship they purchased in a bigger country, and a few smaller patrol boats they built themselves. And when it comes to fighting, it can involve smaller cargo and fishing vessels pressed into service, usually to land troops or perform boarding actions, as they will lack the firepower to sink enemy vessels quickly.

Answer 9

Armed Merchant Ships:

Even with industrialization, it's unlikely that your nations are going to be building any large, dedicated war ships. A shipyard large enough to build such ships would be a stretch, and would likely be needed to build and maintain large enough merchant ships to maintain trade and shipping (which is likely essential to such nations for enough economic strength to be able to fight wars).

The logical solution, however, is to build merchant ships with strategically-located coal bunkers, minimal armor (like protected cruisers) and limited weapons (but likely the capacity to rapidly add additional guns). In a world that might be filled with rival states and pirates, this level of armament is easily justified. Scaling up a merchant ship is going to be significantly cheaper than building dedicated warships. The initial investment in the merchant vessel is already made, and would have been needed for an industrial marine state anyway.

These merchant ships WILL cost more than regular ships, and be slightly less efficient merchant vessels. They will require slightly more crew, especially if being equipped for war at the time. But then the nation's merchant ships will project the nation's power automatically everywhere their merchant ships go. Every ship captain can also be a captain in your navy, and readily make military decisions that support their state. Everywhere they go, you'll have cannons and marines that will outclass any local mobs or yokel militias (gunboat diplomacy).

The cargo holds will allow these vessels to readily transport war materials or be used as troop transports. The fact that they are merchant vessels normally opens opportunities for surprise attacks, since the ships would be visiting foreign ports anyway and would have an excuse to be in the waters of rival states. The transition from commerce to commerce raider would also be effortless, and commerce would likely be the chief target of naval war between rival oceanic states.

Combined with the small dedicated warships like torpedo boats discussed in other answers, it provides a compromise solution that states of you size can reasonably afford.

Answer 10

Limited metal, coal

If these island nations originated in volcanic processes like most of the small pacific islands. they will have no coal no iron in economical concentrations.

Those islands that have continental crust could have metal and coal that are minable.

Limited wood

Most island nations do not have extensive forests to supply building materials for ships. Several island nations like Easter island, UK, Sardinia ran out or low on wood resources at various times in there histories.

Steam engines expensive

Compare Thrust block to tilting pad fluid berings patented 1905.

The low efficiency of thrust blocks means that steam powered ships are expensive and island nations with no coal. they would be even more expensive.

Fleet composition.

Due to the above resource constraints the bulk of the fleets will small craft. Polynesian style vessels would be best, that is small ocean capable craft. Through different designs would probably needed for higher latitudes.

Add in less then two dozen prestige hulls purchased from other large nations. Such prestige hulls as clippers, maybe an ironclad maybe a steamship. Where coal burning ships are generally too expensive to operate.