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 or rocket (enemy or friendly).
A "Set on Fire" ribbon is awarded for each individual fire set on an enemy ship.
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 (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.
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)|
Base Fire Chance
"Projectile Base Fire Chance" for artillery 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. In addition, each ship entry in this wiki includes the fire chances for main and secondary HE shells.
For aircraft bombs and rockets, the base fire chance is a characteristic of the size and type of ordnance used and varies between 4% for small rockets carried by attack squadrons and 64% for large HE bombs. See the tables in the Aircraft article for more info. The information can also be view in the Port screen by mousing over the appropriate type of squadron in the Aircraft section.
The chance to set fire for a single high explosive shell hitting a ship is calculated by the following formula (the formulas for airborne rockets and bombs are similar):
- FRC — the ship's Fire Resistance Coefficient (see above).
- DCM1 — the effect of the Damage Control System Modification 1 upgrade: 5% (0.05) with the upgrade installed, zero without.
- FP — the effect of the Fire Prevention skill: 10% (0.10) with the skill, zero without.
- FCB — the Projectile Base Fire Chance (see above).
- IFHE — the effect of the IFHE commander skill: 1% (0.01) or 3% (0.03) depending on gun caliber, or zero without the skill.
- DE — the effect of the Demolition Expert commander skill: 0.02 with the skill, zero without.
- Σ S — the sum of the effects of the mounted Signals Victor Lima and India X-Ray : +0.01 or +0.005 each depending on gun caliber, else zero.
- 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).
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, 30 seconds for cruisers and destroyers, and 5 seconds for aircraft carriers. 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 2% (0.4% x 5 sec.) of a carrier's.
There are exceptions to the above fire duration for cruisers, the large cruisers: Tier VI Admiral Graf Spee and HSF Admiral Graf Spee have a base fire duration of 45 seconds; Tier IX Kronshtadt, Alaska, and Azuma and Tier X Stalingrad and Yoshino have a base fire duration of 60 seconds. Maximum fire damage is thus 13.5% (0.3% x 45 sec.) for the German Tier VI, and 18% (0.3% x 60 sec.) for the Tier IX and X.
Captains of battleships and large cruisers 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 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.
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 additive.
For example, if all three reduction effects are stacked, the duration of a single fire on a battleship or large cruiser 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.
|Total damage||2.0% of base health||5 seconds|
|Total damage||18% of base health||60 seconds|
|With one -15% modifier||15.3% of base health||51 seconds|
|With a -20% modifier||14.4% of base health||48 seconds|
|With two -15% modifiers||13% of base health||43 seconds|
|With one -15% modifier and a -20% modifier||12.2% of base health||41 seconds|
|With two -15% modifiers and a -20% modifier||10.4% of base health||35 seconds|
|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|
|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.