Ship Design Guidelines

[snip]

Where in doubt, rely on common sense and historical practice. 

This is a "living" document; entries may be added as events or discussions warrant them.

Ship design guidelines

Player and Mod review : Designs shall be posted for Player commentary.  Flawed designs may be built if they meet Tech and Guideline requirements.  The Moderator judgment may be called on to ensure compliance with Tech and Guidelines.  In combat, effectiveness of design elements is subject to the judgment of the person moderating the battle.

Block-coefficients

0.38 is the absolute minimum.  Coefficients should be reflective of the size and speed of the vessel.

Architecture

The Capital Ship Architecture tech applies to any ship carrying guns with a bore diameter of 210mm or more carrying its armament in turrets. If the weapons are less than 210mm or not turreted, the Cruiser Architecture tech applies.

Ships built to Destroyer Architecture must have at least 50% of the Distribution of weights at normal displacement section of their Springsharp allocated to Machinery.

Exceptions to architectural classifications may be granted by the Moderators at their discretion. This is to allow for ships of unusual design or concept, and for certain OTL historical outliers that do not fit easily in this system.

Armor Layouts

The following detail some specifics of the allowed armor layouts.
--All Capital Ships must possess a Main Belt and an Armored OR Protected Deck. They must use either a Traditional or All-or-Nothing layout.
--Traditional Armor Layouts for Capital Ships must have at least a 90mm Upper Belt. This belt must provide reasonable protection for the portion of the freeboard above the main armor belt. Traditional layouts must also possess some form of armor protection along the entire length of the ship. This can be in the form of End Belts and/or For/Aft armor decks. This armor must provide reasonable protection for the ends of the ship.
--All-or-Nothing Armor Layouts for Capital Ships become available after researching the 1910 Capital Ship Architecture tech. Designs constructed to an All-or-Nothing standard have no minimum requirements regarding Upper Belts or full-length protection.
--Armor Layouts for Cruisers may have any combination of Belts and Protected OR Armored decks OR Boxes over Magazines, Engines, or both.
--Ships built to Destroyer Standards may have Belt or Deck armor intended for splinter protection.

Protective decks
Protective decks are set low on the waterline and have slopes to below the waterline, behind the main belt (if any).
A protective deck with no belt, but thicker slopes than crown can be modeled by a 1-deck height main belt and Notes.

Protective decks can be used effectively if "Hull Space" remains below 133%.  Over that amount, assume some important systems are above the deck.
If "Hull Space" exceeds 110%, then important systems extend past the traditional citadel section of hull, and hull is cramped.

Engines and Drive Shafts

The engine year of a ship will be equivalent to the laydown year of that ship or the year in which either a refurbishment or reconstruction has taken place and engine upgrades have been paid for.

Drive Shafts have some special benefits and drawbacks.
Direct Drives: No bonus or penalty
Electric Drives: Take an additional 25% of engine weight in misc weight and provides a 15% bonus to range plus improved compartmentalization (effects number of torpedo hits to sink)
Hydraulic Drives: Takes an additional 10% of engine weight in misc weight and provides a 5% bonus to range.
Geared Drives: Provides a 10% bonus to range.
Diesel Engines: Diesel engines can be used as part of mixed drive units or standalone power. Takes an additional 30% of engine weight in misc weight and provides a 75% bonus to range. Can be combined with Electric, Hydraulic or Geared drives (Bonus and penalties stack).

If a refurbishment or reconstruction changes the type of engine (eg VTE to Turbine), then Electric drives must be used. This is due to the change in shaft runs between various engine types.

Hoists

Protected cruisers should have hoists with the gun mounts, if the appropriate technology has been researched. Destroyers of WWI had no hoists for individual guns.  A cruiser without hoists has a lower sustained rate of fire, and is more vulnerable due to the ammo exposed on the deck.

Hull Strength

Ships are expected to have a Composite Strength of 1.0 except for the following provisions.
--Ships built to the standards of the Cruiser Architecture technology may adhere to any limits stated in the tech held by the constructing nation.
--Ships built to the standards of the Destroyer Architecture technology must have at least a cross-sectional strength of 0.50 instead of a composite strength requirement

Ships not meeting this criterion are at risk of moderator-inflicted incidents.

Length to Beam Ratio

Ratios should be reflective of the size and speed of the vessel.

Length to Beam Ratios of 12:1 (smaller, faster ships) or 10:1 (larger or slower ships) or less are reasonable and do not risk moderator-inflicted incidents.  Ships approaching circular shape (L:B ratio of less than 4:1) risk moderator-inflicted performance issues.

Miscellaneous Weights

This will be added to as new items are suggested or become available.

Boats:  Typical ship's boats are part of fittings.  Extra boats, landing craft, or attack craft require 2 t of miscellaneous weight per tonne of boat weight:  the difference accounts for cranes and hull reinforcements.

Coalling/Oiling Gear:  Considered part of ship's fittings.

Depth-charges:  1 t per three depth charges, including rails.  1 t per thrower, once available.

Fire Control:  Ships may be equipped with a specific generation of fire control by allocating misc weight equivalent to 10% of the armament weight. The generation of fire control must be noted in the comments section of the SpringSharp report. Fire Control is considered to cover all batteries on ships where it is equipped. Ships may be equipped with redundant installations.

Fluff:  Flag facilities, medical facilities, climatization, extra pumps, and so forth are assigned weight as the player sees fit.  Moderators may assign performance bonuses to the ship under specific circumstances if the facilities warrant it.

Mines:  1 t per mine, including associated laying and storage equipment.

Radar and Remote-Hearing Devices:  25 t per installation is recommended, though the effectiveness of these devices is questionable.

Torpedoes:  Do not use the built in Torpedo utility in SS3. Use these weights instead.
16" (1890 Tech): 1.5 t each
18" (1899 and 1905 techs): 2 t each
21" (1908 tech): 3 t each
21" (1913 tech): 4 t each
24" (1918 tech): 5 t each

Troops:  1 t per four troops for short-ranged landing craft.  2 t per troop for long-term (> 1 day) embarkment.

Wireless:  10 t for a short-range (100 mile) set, 25 t for a long range (250+ miles) set.  Redundant installations are allowed.  New construction laid down 1/1/10 or later does not require weight to be set aside for one (1) short-ranged set.

Hydrophones in Navalism.

As detection systems, they do not count as "Armanent".
They come in a "Basic Hydrophone set" 
and an "Enhanced Hydrophone Set".
Their effectiveness is dependent on the nations Submarine technology level. 

The "Basic Hydrophone set" consists of hand-held booms over the ship's side and magnetaphone diaphrams mounted inside the hull, and room for trained operators and parts. Typically this is one omni-directional hydrophone for each side, and a directional hydrophone. This  can be installed dockside in a Basic Refit.

The "Enhanced Hydrophone set" consists of through-hull rotational mountings, hull mounted hydrophone arrays in a blister, and towed arrays... and room for trained operators and parts. This installation must either be built in, or part of a Basic Refit requiring a drydock.


Miscellaneous Weight
5t : 1910 "Basic Hydrophone Package" : 3 boom hydrophones, in-hull PGS internal diaphram and omni-directional mounted arrays. A 300ft electrified cable allows the vessel to trawl for stopped subs on the seabed.

15t : 1915 "Enhanced Hydrophone Package" : 3 boom hydrophones, K 3-Tube style through Hull directional array, WV-hull blister directional array., 3 towed arrays. A 300ft electrified cable allows the vessel to trawl for stopped subs on the seabed.

10t : 1920 Early Sonar & keel dome, spares, operators

Anti-Submarine Armament Miscellaneous Weight
These shall be specified under miscellaneous and can be changed with a Basic Refit.

Baseline ASW
1t per 10 ASW harpoons & storage locker

1905 ASW
1t per ASW Twin Kite : <=12knots, upgrades with tech to ASW Paravane
1t per 60m2 Electro-contact mined nets

1910 ASW
1 t per 10x 90kg depth charges, including rails. DC lethal volume :4200

1915 ASW
1t per ASW Paravane : <=25knots
1 t per Thornycraft Single-DC thrower 40m.
1t per 5 x 195kg depth charges, including rails and handling gear. DC lethal Volume :1,437,000

1920 ASW
1t per 10 x 100kg "Stick-bombs" to fire from 75mm+ light howitzers or deck guns. 
1t per 3x 280kg depth-charges, including rails and handling gear. DC Lethal volume : 3,053,63
1t per "Y" twin-DC Thrower 80m.   

Shafts

Four shafts are the most that may be installed aboard a ship.

Speed

For ships not constructed to Destroyer/TB tech, the SS3 reported top speed is just that. For ships constructed to Destroyer/TB tech, the SS3 reported top speed should be considered that ship's top in-service speed in a seaway. The details of this calculation are posted here, please use the below calculator for ease of use.

Springsharp

SS3b3 is the program we use.  We do not use SS2 or any other software.  If the ship can not be designed from scratch in SS3b3 using our design guidelines and naval technology trees, the design is invalid.

Citadel Length :
Changing the length of the main belt on the Armor tab does not change the amount of deck armor.
The length of belts, and associated decks, should be changed by adjusting the Freeboard tab "Length (% of LWL)" values, and then hitting "Default" on the Armor tab.

Weapons Tab :
We do not use the Torpedo/Mine/DC portions of the weapons tab, these are described and accounted for under Miscellaneous Weight.
Please include the diameter of the torpedoes intended.

Torpedo defense systems (TDS).  Use the "Additional Bulkhead" setting.


Transom Sterns

The utility of this hull form is not yet recognized and is not to be used in designs.

Hulls and Sails

Hull Materials: The 19th Century saw rapid changes in materials that ships hulls were constructed off.  In less than 50 years the worlds battlefleets moved from hulls of Wooden Hulls, to Ironclad, Iron hull and finally steel construction.  These different materials have different abilities to take the load of the ships weight.     

Sail vs. Steam: As the 19th century progressed there was a transition of warships from sail propulsion, to steam backup and finally to all steam propulsion.  The switch over to steam comes because of two reasons.  First is that ships can steam all the time in all weather conditions.  The second is that rigging is a fire hazard and source of possible debris to block the ships deck.  Of course a ship with sails does not need to go to port to coal and doesn't require the ship engine to be maintained.  So sailing ships will remain common in civilian service for a great deal of time.

To simulate the weight of a ships sail gear and the ballast to counter the torque effects the mast has on the hull misc. weight will be used.  A portion will be below the waterline misc. weight and the other as above the deck misc. weight both found on the Weapons tab for SpringSharp3.

There are two types of sail plans that ships can follow. The Full Rigged Ship (3 masted ship) or Brigantine / Brig (2 masted ship).

A full rigged ship can do up to 2/3 of SS hull speed (not ship engine speed but speed based on hull) Displacement costs being 1.5% misc weight above hull for Full Rigged Ship and 6.5% misc weight below deck.  On a 6,000 ton ship this comes out to 480 total misc tons.

A Brigantine can do 1/2 of SS hull speed.  Displacement costs being 1% Misc Weight above hull and 4% misc weight below deck.  On a 6,000 ton ship this comes out to 300 total misc tons.

[Kaiser Kirk]

These are not rules, or guidelines, but more a commentary on how things seem to have been in reality.
It is expected new sections will be added, or old sections corrected,  as players contribute their knowledge.

This is meant as informative, and are general observations from readings.

Where it could effect would be evaluating performance in a combat situation. 
Example : If a 200mm hand loaded gun has been firing for 10 minutes...the crew will be tired and ROF should decline. That doesn't mean someone can't build a 200mm with a mount.


Ship Design Best Practices:

For example, various sources may say that such and such a weapon or mount was slow/difficult/etc. There seems to be a common point these complaints start to occur.

None are mandatory rules or guidelines.   

Wing turrets :
Wing turrets greater than two-gun 12" were not done for practical reasons.
The use of wing turrets was discontinued due to practical consideration (limited arc, deck damage) and structural. Normal turrets and barbette structures easily transfer loads to the keel, on wing turrets this was more difficult and needed additional structure. After roughly twin 12" guns, there is no "real" weight savings from avoiding a superimposed turret.

Practical Notes on Turrets vs. Mounts.
As a practical matter, mounts from the 1905 artillery tech are designed with gearing to allow guns <255 (10") to be kept on target and best able to use fire control.

As a practical matter, a mount over 45tons rotating weight will be slower to train, power assist or a turret may be recommended. This may be a Twin 152mm/53, or a Single 19cm/45.   At weights over 70t, rate of train will be slow and turrets are strongly recommended.

As a practical matter, shells between 60 and 95kg are heavy and the ROF will slowly decrease as the crew gets tired.  Power assist will delay this. Hoists are highly recommended.

Shells over 90kg are difficult to handle and are slow to handload. Power hoists and ramming with a turret is recommended.

Multiple guns
Generally speaking, historical twin mounts had a higher rate of fire (ROF) than the historical triple mounts. Also, ROF on Single-sleeve triple mounts were slower than 3-gun triple mounts. The reason is apparently the loading cycle. Actual rates of fire would vary by bore, nation and date of design. There are even cases where more practice and procedural changes increase a guns ROF.  Some of those changes could simply be to throw safety precautions away.

The use of a single slide gives ~90% of the ROF of a "x-gun" design.
Adding a 2nd or 3rd barrel each applies ~90% reductions.

A "Quad" is a single slide,
while "Pair of Twins" is a "4-gun" and treated as 2 Twins for ROF.
A "True Quad" is also a "4-gun" and treated as 2 Two Guns for ROF.

Example : A 2-Gun 14" Turret - ROF 2 / barrel
A single 14 would then be 2 (base ROF) / 0.9 (only 1 barrel) = 2.22 ROF
A Triple 14" Turret then would have = 2 (base ROF) * 0.9 (+1 barrel)  * 0.9 *single slide) = 1.62 ROF / Barrel

The "Quad" effect is unknown, but it the "pair of twins" quad apparently avoids a reduction by having two ammo feeds, turning the turret into a 'pair of twins' with that ROF.

Gun design
High Muzzle Velocity is advantageous, particularly at short range, where it yields a flatter shot arriving with more kinetic energy.
Numerous countries pushed MV higher, but when it reaches in the 930-950m/s range, you find comments about excessive barrel wear and dispersion. 
In the case of some guns, they were deliberately derated to fire at lower velocities.
Velocities over 900m/s are of questionable value, and 915-920 might be a practical maximum for a decent gun, but numbers in the 750-850m/s are more common.

For very long ranges, where deck hits became more common, a heavier and slower shell with more deck penetration can be advantageous.

Torpedo defense systems (TDS).   
A TDS around WWI typically had a 3+m deep TDS with a 38-40mm armored bulkhead or more. This required more beam for the ship.  Later torpedo defense systems added more armored partitions and greater depth, frequently paired with an outer bulge.

These areas provided "expansion space" and absorbed the waterhammer of the torpedo.

The inner, Armored bulkhead was meant to stop fragments of the torpedo, hull, and framing members from blowing holes in it. This was usually a highly ductile armor steel that would stretch and deform before failing. Frequently plates 18-25mm were twinned together, or a single 38-51mm plate was used.

An 8mm holding bulkhead inboard of a 2m wide passage, such as Bretange should be viewed as nothing more than a means of flooding control.

Fire Control
For splash spotting, salvos of 4+ guns are desirable.

Early on, they wanted 10 guns, so 5 would fire in a salvo, and if 1 had a loading delay there would be 4 guns.  Later, they decided the delays were not common, and they could use 8 guns for the 4 shell salvo.

Lesser patterns can work, but with less effectiveness.

Fire Control Ranges :
As listed under Technology for effective range.
Attempted fire beyond that range within several thousand meters drops to 1-2% hit chance.

Shell splash spotting is limited by shell size. Spotting is effective at 1,000m per 1cm of shell size.
Fire control past this is difficult.

Capital Ship & Cruiser Architecture : a least one director per weapon class (surface/dp/aa) is included.
Capital and cruisers architecture have an Auxiliary main director allowing split fire against one additional target.
Capital ship architecture have port & starboard sets of directors for secondary/tertiary, cruisers do not.

Turrets : Turrets are assumed to have built in rangefinders, (equal to 1900-19 Top Spot) usable independently of main and secondary FC.

Lesser mountings, if no director input, rely on Local Spot.

Torpedoes : If the Vessel has FC, information as to target range, speed, and bearing will be relayed to the torpedo position. No specific FC is provided.

Redundant fire control duplicates the entire system.

Engines
Reciprocating engines are unreliable, and prone to problems after the first hour at 100% power.
For N7, 75% power is the assumed reliable maximum for long periods.

Coal fired boilers build up 'clinker' which has to have the boiler shut down to clean out every several hours. For N7, 75% power is the assumed reliable maximum for long periods.

Coal fired boilers take great labor to run at full power, which can be done on merchants for one hour at most, a bit over an hour on warships.  Some cruisers and attack vessels may have extra stokers and be able to manage full power for 2 hours.