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Fortresses

Fortresses may be built in a number of sizes. A nation must posess the applicable Infantry tech (listed in the first column) before they can build or upgrade a fortress at that level. To upgrade a fortress's level or size costs simply the difference in price between the old fortress and the new.

When the garrison manning a fortress is forced to leave their prepared defenses, they become 'detached', and their maintenance costs and fighting characteristics become as those listed in the second half of the table below.

Fortresses require one half year per citadel to construct or expand.



Fortified Lines

Fortified lines are another type of static defense emplacement. They are generally used for static defense against an attacking enemy. In general, their characteristics are similar to their corresponding infantry units, with the additions of static defense elements like trenchworks and additional artillery.

When the garrison manning a fortified line is forced to leave their prepared defenses, they become 'detached', and their maintenance costs and fighting characteristics become as those listed in the second half of the table below.

As is the case with forts, a nation must possess the applicable infantry tech listed in the first column of the table before a fortified line of that level may be constructed. Fortified lines may be upgraded from level to level or added to in length at a cost of simply the difference in $ and BP between the old line and the new.

Fortified lines require one half year per 10 km to construct.

Coast Defense

Coast defense batteries may be constructed. Guns may be emplaced in turrets, in casemates, or in pits on disappearing carriages. The costs differ for each option according to the table below. The standard emplacement of a coastal gun can be expected to withstand damage from a projectile fired from a gun of similar caliber, with a few exceptions.

In addition, coast defense guns may be provided with 'extra defense' or 'massive defense' emplacements. This has the effect of adding to the amount of punishment that emplacement can take. Extra defense means that a gun can successfully withstand a hit from a typical projectile from the next size up gun in the table below. Massive defense means that the gun can successfully withstand nearly any foreseeable enemy projectile. In both cases, the weapons themselves must be exposed, and are still subject to damage or destruction by a direct hit.

Turrets have the advantage over casemates of a much wider field of fire. Disappearing carriages have a nearly unlimited field of fire similar to turrets, but remain open to plunging fire from above, no matter what protection has bee provided for them.

To calculate the costs of coast defense batteries, add up the costs in $ and BP of each gun equipping that battery, plus the costs for extra or massive defense, again per gun. Upkeep percentages are the same as those used for naval ships. The values in the table are provided for reference.

For example, a 4x15" casemate battery with extra defense provided would cost:

0.75 * 4 = $3 and 3BP, plus 2 * 4 = $8 and 8BP for extra defense. The total is $11 and 11 BP.

Maintenance for the same battery would be:
Mobilized: $11 / 40 = $0.275 per half
Active: $11 / 80 = $0.1375
Reserve: $11 / 400 = $0.0275

It is assumed that any coastal battery includes necessary communications and fire control systems.

Coast defense guns 8.01" and larger require 6 months to construct the gun, and 6 months to install it, for a total of 1 year for project completion. Guns below 8.01" require 3 months to construct the gun, and 3 months to install it, for a total of 6 months for project completion.




Guns or whole turrets may be reused in coast defense batteries, in which case the cost of that battery is reduced.

When reusing just guns themselves:
Turreted Coast defense battery, reduce cost in $ and BP by 1/6 compared to that built with a new gun.
Casement Coast defense battery, reduce cost in $ and BP by 1/3 compared to that built with a new gun.
Disappearing Carriage Battery, reduce cost in $ and BP by 2/3 compared to that built with a new gun.

Re-using a turret with it's guns guns:
Turreted coast defense battery, reduce cost in $ and BP by 1/2 compared to that of building a new turret and guns.

These cost adjustments are applied before the cost for extra or massive defense is added.


Coast Defence Mortars

A common weapon during the 1800s and into the early 1900s, large mortars were also used as coast defence weapons, dropping heavy projectiles onto the poorly protected decks of enemy ships.  Their high-arching trajectories meant that correct prediction of enemy course and speed were even more important for these weapons.  These weapons were generally deployed behind coastal hills, which provided protection from enemy observation and flat-trajectory fire.  Their open-topped gun pits, however, would prove vulnerable to aerial observation and attack.

For sim purposes, coast mortars will be costed as parapet batteries.