Fire
Contents
Setting Fires
Hits from two types of ordnance can cause a ship to catch on fire:
- A high explosive shell (enemy or friendly) from a main or secondary battery.
- An aircraft bomb (enemy or friendly).
Fire Zones
Every ship has four distinct zones along its main deck that can be set on fire, fore, aft, and two amidship. Thus the maximum number of fires on a ship is four. The commander skill Fire Prevention reduces the number of fire zones to three (one amidship).
Fire Chance
Fire Chance (the chance a shell or bomb will set a fire) is calculated by combining a base chance for the ordnance to set a fire, the target ship's intrinsic resistance to fire, and certain modifiers, as shown below.
Fire Resistance
Each ship hull has an intrinsic resistance to fire. The amount of resistance is based on ship type, ship tier, and the hull that is currently equipped (Stock or Top). (Premium ships all have the Top Hull.) This resistance is expressed as the Fire Resistance Coefficient (FRC). The lower the coefficient, the more resistant the ship is to catching fire.
The Fire Resistance Coefficients (FRC) are shown below:
Ship Tier | (Stock Hull) | (Top Hull) | (all) |
---|---|---|---|
Tier I | 1.0000 | N/A | |
Tier II | |||
Tier III | 1.0000 | 0.9667 | |
Tier IV | 0.9334 | 0.9001 | 0.8002 |
Tier V | 0.8668 | 0.8335 | |
Tier VI | 0.8002 | 0.7669 | |
Tier VII | 0.7336 | 0.7003 | |
Tier VIII | 0.6670 | 0.6337 | |
Tier IX | 0.6004 | 0.5671 | |
Tier X | 0.5338 | 0.5005 |
Base Fire Chance
The chance to set fire for a single high explosive shell (or aircraft bomb) hitting a section is calculated by the following formula:
"Projectile Base Fire Chance" is displayed in the Port screen by mousing over the Main Battery or Secondary Armament entries in the Artillery section. Only HE shells have a Fire Chance.
For aircraft bombs, the base fire chance is a fixed number based on the size and type of ordnance used and varies between 1.08 (for the 140 lb. bombs carried by Kaga) and 1.65 (for the 1000 kg bombs deployed aboard Graf Zeppelin). See the Aerial Combat page for more info.
The Calculation
where:
- FRC - the ship's Fire Resistance Coefficient
- DCM1 - the effect of the Damage Control System Modification 1 upgrade: 5% (0.05) with the upgrade installed, 0.0 without
- FP - the effect of the Fire Prevention skill: 10% (0.10) with the skill, 0.0 without
- FCB is the Projectile Base Fire Chance; see Base Fire Chance above.
- IFHE is the effect of the IFHE commander skill: 1% (0.01) for gun calibers up to and including 139mm, 3% (0.03) for gun calibers above 139mm, and zero without the skill
- DE is the effect of the Demolition Expert commander skill: 0.02 with the skill, 0.0 without
- Σ S - the sum of the effects of mounted Signals, e.g. Victor Lima and India X-Ray : +1% or +0.5% each depending on gun caliber
As an example, we can compare the chance of a single Benson high explosive shell lighting a fire on an enemy Bismarck.
- The Tier VIII Bismarck is using Hull B (Top) (FRC of 0.6337) and Damage Control System Modification 1; his commander is not skilled at Fire Prevention.
- Benson fires 127mm HE Mk. 32 with a 5.5% base fire chance. Her commander is a Demolition Expert (not IFHE) and is flying both the Victor Lima and India X-Ray signals.
The fire chance (per hit) would be:
(0.6337) x (1 - 0.05 - 0.00) x (0.055 - 0.0 + 0.02 + 0.01) = 5.12% fire chance
If the Bismarck commander acquires the Fire Prevention skill, the chance would then be:
(0.6337) x (1 - 0.05 - 0.10) x (0.055 - 0.0 + 0.02 + 0.01) = 4.58% fire chance
If the Benson commander didn't have Demolition Expert or the signals equipped, the chance would be:
(0.6337) x (1 - 0.05 - 0.10) x (0.055 - 0.0 + 0.0 + 0.0) = 2.96% fire chance
The above example can be used to demonstrate the usefulness of the Demolition Expert skill on certain ships, especially those with a high rate of fire and a low individual fire chance per shell (such as Atlanta, Gearing, or Akizuki).
Fire Damage
Damage dealt by each instance of fire on a ship is fixed as 0.3% of its total health pool per fire per second (0.4% for aircraft carriers). Each fire has a base duration of 60 seconds for battleships and aircraft carriers, and 30 seconds for cruisers and destroyers. A fire that is allowed to burn for the full duration will consume 18% (0.3% x 60 sec.) of a battleship's maximum health, 9% of a cruiser's or destroyer's maximum health, and 24% (0.4% x 60 sec.) of a carrier's.
There are currently four exceptions to the above fire duration for cruisers, the large cruisers: Tier VI Admiral Graf Spee and HSF Admiral Graf Spee, Tier IX Kronshtadt and Tier X Stalingrad have a base fire duration of 45 seconds.[2] Maximum fire damage is thus 13.5% (0.3% x 45 sec.) for these ships.
Captains of capital ships — aircraft carriers and battleships — can quickly see, then, that while one fire might be considered a nuisance, two or more are a major threat to the ship.
Other Effects of Fire
- Ships that are on fire have their surface detection range increased by 2.0 km and their aerial detection radius increased by 3.0 km. This is particularly noteworthy for destroyer captains.
- Aircraft carriers that are on fire cannot launch or recover aircraft, unless their commander has trained the Emergency Takeoff skill which allows planes to take off and land while the flight deck is on fire at the cost of double the servicing time.
Extinguishing Fires
Fires can only be extinguished by utilization of the Damage Control Party consumable, or by waiting for the fire duration timer to expire. The duration of a fire can be reduced in several ways:
- Equipping Damage Control System Modification 2 will reduce the duration by 15%.
- Using a commander with the Level 3 commander skill Basics of Survivability will reduce the duration by 15%.
- Flying the India Yankee () signal will reduce the duration by 20%.
Each of these effects stacks with the others; however, they are multiplicative rather than cumulative.
For example, if all three reduction effects are stacked, the duration of a single fire on a battleship or carrier is: 60 seconds x 0.85 x 0.85 x 0.80 = 34.68 seconds.
The below tables provide the fire durations and total health loss for the different combinations of the above three effects.
Modifiers | Total Damage to Battleships | Total Damage to Carriers | Duration |
---|---|---|---|
Total damage | 18% of base health | 24% of base health | 60 seconds |
With one -15% modifier | 15.3% of base health | 20.4% of base health | 51 seconds |
With a -20% modifier | 14.4% of base health | 19.2% of base health | 48 seconds |
With two -15% modifiers | 13% of base health | 17.3% of base health | 43 seconds |
With one -15% modifier and a -20% modifier | 12.2% of base health | 16.3% of base health | 41 seconds |
With two -15% modifiers and a -20% modifier | 10.4% of base health | 13.9% of base health | 35 seconds |
Modifiers | Total Damage | Duration |
---|---|---|
Total damage | 13.5% of base health | 45 seconds |
With one -15% modifier | 11.5% of base health | 38 seconds |
With a -20% modifier | 10.8% of base health | 36 seconds |
With two -15% modifiers | 9.8% of base health | 33 seconds |
With one -15% modifier and a -20% modifier | 9.2% of base health | 31 seconds |
With two -15% modifiers and a -20% modifier | 7.8% of base health | 26 seconds |
Modifiers | Total Damage | Duration |
---|---|---|
Total damage | 9% of base health | 30 seconds |
With one -15% modifier | 7.7% of base health | 26 seconds |
With a -20% modifier | 7.2% of base health | 24 seconds |
With two -15% modifiers | 6.5% of base health | 22 seconds |
With one -15% modifier and a -20% modifier | 6.1% of base health | 20 seconds |
With two -15% modifiers and a -20% modifier | 5.2% of base health | 17 seconds |
All damage sustained by fires is 100% eligible for recovery by ships that can use the Repair Party consumable. Note that a standard Repair Party heals up to 14% of a ship's base health (16.8% with the India Delta () signal) over 28 seconds, comparable to a single fire on a battleship depending on other modifiers.
Notes
- ↑ Note that the Fire ribbon is also awarded when a fire would be set, but is not because of a Damage Control immunity period.
- ↑ 2.0 2.1 The upcoming Tier IX Alaska and Tier X Azuma will fall into this category.