Fortifications, Siege Artillery, and Coast Defense

[Guinness]

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.

Rating Artillery Money BP Mobilized Active Reserve Manpower 1 Citadel Fortress 1880 Dated 0.5 0.5 $2 0.125 $0.200 $0.100 $0.020          2,750 1895 Baseline 0.667 1 $2.667 0.250 $0.267 $0.133 $0.027          2,750 1905 Advanced 0.833 1.5 $3.333 0.375 $0.333 $0.167 $0.033          2,750 1915 Cutting Edge    1 2 $4 0.5 $0.400 $0.200 $0.040          2,750 3 Citadel Fortress 1880 Dated 1.5 1.5 $6 0.375 $0.600 $0.300 $0.060          8,250 1895 Baseline 2 3 $8 0.75 $0.800 $0.400 $0.080          8,250 1905 Advanced 2.5 4.5 $10 1.125 $1.000 $0.500 $0.100          8,250 1915 Cutting Edge    3 6 $12 1.5 $1.200 $0.600 $0.120          8,250 6 Citadel Fortress 1880 Dated 3 3 $12 0.75 $1.200 $0.600 $0.120         16,500 1895 Baseline 4 6 $16 1.5 $1.600 $0.800 $0.160         16,500 1905 Advanced 5 9 $20 2.25 $2.000 $1.000 $0.200         16,500 1915 Cutting Edge    6 12 $24 3 $2.400 $1.200 $0.240         16,500 12 Citadel Fortress 1880 Dated 6 6 $24 1.5 $2.400 $1.200 $0.240         33,000 1895 Baseline 8 12 $32 3 $3.200 $1.600 $0.320         33,000 1905 Advanced 10 18 $40 4.5 $4.000 $2.000 $0.400         33,000 1915 Cutting Edge    12 24 $48 6 $4.800 $2.400 $0.480         33,000 18 Citadel Fortress 1880 Dated 9 9 $36 2.25 $3.600 $1.800 $0.360         49,500 1895 Baseline 12 18 $48 4.5 $4.800 $2.400 $0.480         49,500 1905 Advanced 15 27 $60 6.75 $6.000 $3.000 $0.600         49,500 1915 Cutting Edge    18 36 $72 9 $7.200 $3.600 $0.720         49,500 1 Citadel Fortress Garrison (Detached) 1880 Dated 0.165 0 NA NA $0.033 $0.017 $0.003          2,750 1895 Baseline 0.220 0 NA NA $0.044 $0.022 $0.004          2,750 1905 Advanced 0.275 0 NA NA $0.055 $0.028 $0.006          2,750 1915 Cutting Edge    0.330 0 NA NA $0.066 $0.033 $0.007          2,750 3 Citadel Fortress Garrison (Detached) 1880 Dated 0.495 0 NA NA $0.099 $0.051 $0.009          8,250 1895 Baseline 0.660 0 NA NA $0.132 $0.066 $0.012          8,250 1905 Advanced 0.825 0 NA NA $0.165 $0.084 $0.018          8,250 1915 Cutting Edge    0.990 0 NA NA $0.198 $0.099 $0.021          8,250 6 Citadel Fortress Garrison (Detached) 1880 Dated 0.990 0 NA NA $0.198 $0.102 $0.018         16,500 1895 Baseline 1.320 0 NA NA $0.264 $0.132 $0.024         16,500 1905 Advanced 1.650 0 NA NA $0.330 $0.168 $0.036         16,500 1915 Cutting Edge    1.980 0 NA NA $0.396 $0.198 $0.042         16,500 12 Citadel Fortress (Detached) 1880 Dated 1.980 0 NA NA $0.396 $0.204 $0.036         33,000 1895 Baseline 2.640 0 NA NA $0.528 $0.264 $0.048         33,000 1905 Advanced 3.300 0 NA NA $0.660 $0.336 $0.072         33,000 1915 Cutting Edge    3.960 0 NA NA $0.792 $0.396 $0.084         33,000 18 Citadel Fortress (Detached) 1880 Dated 2.970 0 NA NA $0.59 $0.31 $0.05         49,500 1895 Baseline 3.960 0 NA NA $0.79 $0.40 $0.07         49,500 1905 Advanced 4.950 0 NA NA $0.99 $0.50 $0.11         49,500 1915 Cutting Edge    5.940 0 NA NA $1.19 $0.59 $0.13         49,500

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.

Rating Artillery Money BP Mobilized Active Reserve Manpower 10 Kilometer Fortified Line (Half-Division) 1880 Dated 0.75 0.5 $3 0.125 $0.300 $0.150 $0.030 12,500 1895 Baseline 1 1 $4 0.25 $0.400 $0.200 $0.040 12,500 1905 Advanced 1.25 1.5 $5 0.375 $0.500 $0.250 $0.050 12,500 1915 Cutting Edge    1.5 2 $6 0.5 $0.600 $0.300 $0.060 12,500 20 Kilometer Fortified Line (Division) 1880 Dated 1.5 1 $6 0.25 $0.600 $0.300 $0.060 25,000 1895 Baseline 2 2 $8 0.5 $0.800 $0.400 $0.080 25,000 1905 Advanced 2.5 3 $10 0.75 $1.000 $0.500 $0.100 25,000 1915 Cutting Edge    3 4 $12 1 $1.200 $0.600 $0.120 25,000 40 Kilometer Fortified Line (Corps) 1880 Dated 3 2 $12 0.5 $1.200 $0.600 $0.120 50,000 1895 Baseline 4 4 $16 1 $1.600 $0.800 $0.160 50,000 1905 Advanced 5 6 $20 1.5 $2.000 $1.000 $0.200 50,000 1915 Cutting Edge    6 8 $24 2 $2.400 $1.200 $0.240 50,000 Half-Division Sized Garrison (Detached), Fortified Line 1880 Dated 0.25 0 NA NA $0.050 $0.025 $0.005 12,500 1895 Baseline 0.5 0 NA NA $0.100 $0.050 $0.010 12,500 1905 Advanced 0.75 0.125 NA NA $0.150 $0.075 $0.015 12,500 1915 Cutting Edge    1 0.25 NA NA $0.200 $0.100 $0.020 12,500 Division Sized Garrison (Detached), Fortified Line 1880 Dated 0.5 0 NA NA $0.100 $0.050 $0.010 25,000 1895 Baseline 1 0 NA NA $0.200 $0.100 $0.020 25,000 1905 Advanced 1.5 0.25 NA NA $0.300 $0.150 $0.030 25,000 1915 Cutting Edge    2 0.5 NA NA $0.400 $0.200 $0.040 25,000 Corps Sized Garrison (Detached), Fortified Line 1880 Dated 1 0 NA NA $0.200 $0.100 $0.020 50,000 1895 Baseline 2 0 NA NA $0.400 $0.200 $0.040 50,000 1905 Advanced 3 0.5 NA NA $0.600 $0.300 $0.060 50,000 1915 Cutting Edge    4 1 NA NA $0.800 $0.400 $0.080 50,000

Siege Artillery

A siege artillery battery is actually a regular Army unit which is specialized only in artillery bombardment, and has no infantry fighting power. A nation must possess the applicable Infantry tech (listed in the first column) before they can acquire a siege artillery battery of that level. The cost to upgrade a siege artillery battery is simply the difference in cost between the old level and the new.

Rating Artillery Money BP Mobilized Active Reserve Manpower Siege Artillery, Battery 1880 Dated 0 0.5 $2 0.125 $0.200 $0.100 $0.020 500 1895 Baseline 0 1 $2.667 0.250 $0.267 $0.133 $0.027 500 1905 Advanced 0 1.5 $3.333 0.375 $0.333 $0.167 $0.033 500 1915 Cutting Edge   0 2 $4 0.5 $0.400 $0.200 $0.040 500

[Guinness]

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 have 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.
 

Turret Disappearing Carriage Cost Upkeep Cost Upkeep Gun Size $ BP Mobilized Active Reserve Gun Size $ BP Mobilized Active Reserve 18.01 - 20" 3.00 3.00 0.0750 0.0375 0.0075 18.01 - 20" 0.75 0.75 0.0188 0.0094 0.0019 16.01 - 18" 2.2 2.2 0.0550 0.0275 0.0055 16.01 - 18" 0.55 0.55 0.0138 0.0069 0.0014 14.01 - 16" 1.5 1.5 0.0375 0.0188 0.0038 14.01 - 16" 0.38 0.38 0.0095 0.0048 0.0010 12.01 - 14" 1 1 0.0250 0.0125 0.0025 12.01 - 14" 0.25 0.25 0.0063 0.0031 0.0006 10.01 - 12" 0.65 0.65 0.0163 0.0081 0.0016 10.01 - 12" 0.17 0.17 0.0043 0.0021 0.0004 8.01 - 10" 0.38 0.38 0.0095 0.0048 0.0010 8.01 - 10" 0.1 0.1 0.0025 0.0013 0.0003 6.01 - 8" 0.19 0.19 0.0048 0.0024 0.0005 6.01 - 8" 0.04 0.04 0.0010 0.0005 0.0001 6" or less 0.08 0.08 0.0020 0.0010 0.0002 6" or less 0.02 0.02 0.0005 0.0003 0.0001 Casemate Extras Cost Upkeep Cost Upkeep Gun Size $ BP Mobilized Active Reserve $ BP Mobilized Active Reserve 18.01 - 20" 1.50 1.50 0.0375 0.0188 0.0038 14.01" + ED 2 2 0.0500 0.0250 0.0050 16.01 - 18" 1.1 1.1 0.0275 0.0138 0.0028 14.01" + MD 6 6 0.1500 0.0750 0.0150 14.01 - 16" 0.75 0.75 0.0188 0.0094 0.0019 8.01" - 14.01" ED 0.68 0.68 0.0170 0.0085 0.0017 12.01 - 14" 0.5 0.5 0.0125 0.0063 0.0013 8.01" - 14.01" MD 2 2 0.0500 0.0250 0.0050 10.01 - 12" 0.33 0.33 0.0083 0.0041 0.0008 8" or less ED 0.13 0.13 0.0033 0.0016 0.0003 8.01 - 10" 0.19 0.19 0.0048 0.0024 0.0005 8" or less MD 0.38 0.38 0.0095 0.0048 0.0010 6.01 - 8" 0.08 0.08 0.0020 0.0010 0.0002 ED = Extra Defense: Provides protection against a projectile one caliber band larger than the gun that is protected. 6" or less 0.04 0.04 0.0010 0.0005 0.0001 MD = Massive Defense: Is virtually impervious to enemy fire

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.

[Guinness]

Edits:

29 Oct 2009 (for 1/1918): This replaces the old rules on the subject, which can be found here:
http://www.navalism.org/index.php?topic=135.0

30 Oct 2009: Updated with time required to construct fortresses, fortified lines, and coast defense guns.

05 Nov 2009: Update the headings of the smallest example of fortified lines from "brigade" to "half-division".

07 Nov 2009: Added rules for reusing naval guns in coast defense batteries.