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Iwami B is a Tier VIII Japanese torpedo-equipped battleship: she carries deck torpedoes reaching 15 km on a hull most BBs lack. The torps are a brawl-range threat that forces approaching ships to peel off or eat a wave; the main battery is the primary damage source, the torps are the trap. Standout traits: best punchy HE secondaries in T8 BBs (2,600) and top-decile heavy secondary DPM in T8 BBs (330,500).
Anchor a flank at 14-17 km where flanking ships have to cross your torpedo arcs to push. The torpedoes are a deterrent that closes off whole lanes (under 15 km threat); use that pressure to force enemies into your main battery, then dump torps as a finisher when they commit. Bow on between salvos to keep the citadel angled.
The torpedoes are a trap that closes a lane, not a primary weapon; turn out of a launch if the angle exposes the citadel, and use the threat alone to force lane choices. A dead torpedo BB never drops a torp.
Iwami B is a Premium ship and not available to unlock in the Tech Tree. Acquisition paths: Containers and Campaign. Container chances are shown as the listed odds of receiving this exact ship, dividing grouped ship-pool odds across the resolved ships and including nested container paths when a crate can drop another crate.
Pair with a commander whose unique skill complements her main armament; check the build tool for current recommendations.
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Where Iwami B sits among Tier VIII BBs (31 ships). Notable standouts are shown first; the rest of the cohort-ranked stats are in the expand below. Acquisition variants (Black Friday, Founders Edition) are counted once with their base ship, not as separate peers.
Not standouts for Iwami B -- here's where she sits on every other ranked stat in the cohort. Stats tagged NORM are tied across more than half the cohort, so the value is the cohort default rather than a standout.
Damage Control Party∞ charges · 80 s reload · 10 s active
Repair Party3 charges · 80 s reload · 28 s active · 11,298 HP (14% of max HP) total heal (per charge) 
Secondary Battery Booster3 charges · 160 s reload · 30 s active · +100% grouping · -50% dispersionAll values are ship base stats with modifications and upgrade changes denoted inline.
Numbers the spec table cannot show directly: alpha-strike math, DPM, dispersion, AP penetration. Click the formula chip on any row to reveal how it is calculated.
Horizontal dispersion ellipse width at max range, from the verified WoWS dispersion model: $\sigma_H = \left(\dfrac{R}{30}\cdot\dfrac{\text{idealRadius}-\text{minRadius}}{\text{idealDistance}} + \text{minRadius}\right)\cdot 30$ $= \left(\dfrac{17177}{30}\cdot\dfrac{10-2.8}{1000} + 2.8\right)\cdot 30 = 207.7\,\text{m}$How wide your shells scatter at 10 km, from the same dispersion model as the max-range figure above. Picking a fixed range makes this number directly comparable from ship to ship: max-range dispersion makes a longer-range gun look worse even when it's tighter at any common range. The interactive Dispersion tab on the Charts card plots the full curve from 0 to max range.Vertical dispersion ellipse height at max range: $\sigma_V = \sigma_H \cdot \text{radiusOnMax}$ $= 207.7 \cdot 0.8 = 166.1\,\text{m}$How tall the same scatter ellipse is at 10 km. Comparable from ship to ship for the same reason as the width value above.50%-hit horizontal radius: $\sigma_{H,50} = \sigma_H \cdot \text{GetHalfHitsRatio}(\sigma)$ $= 207.7 \cdot 0.332\;(\sigma = 1.9) = 68.9\,\text{m}$50%-hit vertical radius: $\sigma_{V,50} = \sigma_V \cdot \text{GetHalfHitsRatio}(\sigma)$ $= 166.1 \cdot 0.332\;(\sigma = 1.9) = 55.1\,\text{m}$Canonical community AP formula (jcw780/wows_shell), evaluated at muzzle velocity: $P = 10^{-7}\cdot K \cdot m^{0.69} \cdot d^{-1.07} \cdot v_0^{1.38}$ $= 10^{-7}\cdot 2650 \cdot 1020^{0.69} \cdot 0.41^{-1.07} \cdot 834^{1.38} = 880.5\,\text{mm}$. Matches the in-game spec card.Same formula at the ship's max firing range (21.5 km), where the shell has slowed to 502.1 m/s: $P = 10^{-7}\cdot 2650 \cdot 1020^{0.69} \cdot 0.41^{-1.07} \cdot 502.1^{1.38} = 437.1\,\text{mm}$.68 mm ≈ 410 mm caliber / 6 (standard HE penetration ratio).floor(410 mm caliber / 14.3) = 28 mm (AP auto-penetrates plating this thick or less).AP shell over-penetration splash radius; scales with shell mass. Wickes 102mm = 3, standard 152mm CL ~ 20, Iowa 406mm ~ 270, Yamato 460mm = 400, Incomparable 650mm = 550 (max). Larger value = bigger splash damage area when AP over-pens.All 8 barrels bear on the broadside.180 degrees / 5.14 deg/s traverse speed = 35 s.6,500 HE damage x 8 broadside guns = 52,000.13,600 AP damage x 8 broadside guns = 108,800.52,000 HE full-salvo alpha x 60 / 25 s base reload = 124,800.108,800 AP full-salvo alpha x 60 / 25 s base reload = 261,120.52,000 HE full-salvo alpha x 60 / 22.5 s installed reload (Main Battery Mod. 3 = -10%) = 138,667.108,800 AP full-salvo alpha x 60 / 22.5 s installed reload (Main Battery Mod. 3 = -10%) = 290,133.8 broadside guns x 60 / 25 s base reload = 19.2.8 broadside guns x 60 / 22.5 s installed Artillery reload = 21.3.19.2 shells/min x 30% fire chance = 5.76.21.3 shells/min x 30% fire chance = 6.4.detectability / (speed kt x 2.6 community game-speed factor).range / (speed kt x 2.6 community game-speed factor).2 launchers x 4 tubes.tube count / 2 (symmetric port/starboard launcher layout; common on cruisers and battleships with deck torpedoes).All tubes hitting one target: tubes x per-torpedo simulated damage = 8 x 19,567 = 156,536.One side firing, all torpedoes hitting: per-side tubes x per-torpedo simulated damage = 4 x 19,567 = 78,268.Sum across every AA aura on this ship of (aura.continuous_damage x 3.5 x aura.hit_probability). Here: (129×3.5×0.85) + (56×3.5×0.75) = 531. Covers AA-only mounts plus dual-purpose secondaries (Bismarck 105mm, USN 5"/38 cruiser secondaries) and dual-purpose main batteries (Sumner-class 5"/38, Akizuki-line 100mm). Formula validated against in-game captures on California, Sumner, Manfred von Richthofen, Dante Alighieri (exact) and within +/-17% on the remaining verified ships.Longest-reaching aura across AA-only + dual-purpose auras.SUM over AA auras of (aura DPS x aura range km). A plane crossing the AA bubble is exposed to each aura for a time proportional to that aura's range, so long-reach DPS is worth more than the same DPS in a short bubble. Units: DPS*km; used to rank overall AA threat across the cohort.Max dispersion = range (km) × 57 + 30. Each dispersion type sets its own slope; this is not a percentage applied to a standard baseline.6 km × 57 + 30 = 372 m.Sum across all secondary families of (per-side barrels × 60 / reload_s × alpha), where per-side barrels = mounts × barrels-per-mount / 2 (the guns that bear on one broadside target). Per-family: 8×2 100 mm (8/side) × 60/3 × 1700 = 272,000 + 3×3 155 mm (4.5/side) × 60/12 × 2600 = 58,500. Assumes every shell hits (real hit rate is lower; the Brawl matchup tool on the Compare page folds in dispersion + target armor).Maximum HE damage per shell across secondary HE families. Best on this ship: 2600 from the 155 mm family.Maximum per-shell fire chance across secondary HE families (before target fire resistance is applied). Best on this ship: 10% from the 155 mm family.Maximum HE armor penetration across secondary HE families (caliber × 1/6 for most nations; 1/4 for German/UK BBs). Shells whose pen falls under a plate's armor thickness shatter for 0 hull damage though fire chance still applies. Best on this ship: 26 mm from the 155 mm family.Hull HP 80,700, distributed across 5 hull zones, each with its own plate thicknesses, saturation cap, and pen thresholds. HP caps are estimated from the standard WoWs damage-allocation model.
Overmatched by 7 guns here: Incomparable SE 25IncomparableYamato and 4 more. Angling still helps against the rest.
Citadels come from a flat broadside at close range; held past ~30° of angle, AP shatters or bounces.
Superstructure and extremities take HE pens and AP overpens from nearly any gun: steady chip damage. Fire resistance 40%, fires burn 60s. Range-by-range in the ballistics tool →
| Section | Plates | HP cap | Threats | Tactic |
|---|---|---|---|---|
| Bow | 32 mm primary (range 32–360 mm) | ≈ 4,035 (~5% of HP) | Overmatched by 460mm+ (Aki, Musashi)Angle bounces 410mm32 mm: HE pens from 203mm+ | Bow-tank fits behind this exterior plate. Saturation is FAST here; the cap is often only a few thousand HP. |
| Hull (midship) | 360 mm primary (range 45–380 mm) | ≈ 60,525 (~75% of HP) | No common caliber overmatches360 mm: no common HE pens | Largest HP pool. Citadel sits behind these plates; thinner deck and side plating absorb the rest. |
| Stern | 32 mm primary (range 32–356 mm) | ≈ 4,035 (~5% of HP) | Overmatched by 460mm+ (Aki, Musashi)Angle bounces 410mm32 mm: HE pens from 203mm+ | Mirror of bow. Same fast saturation. |
| Citadel | 356 mm primary (range 38–360 mm) | no cap | Citadel pen: full damageOver-pen: ×0.10 damage | Effectively no cap; citadel pool sits at ~165k HP on every ship. An AP citadel penetration deals the shell's full damage, the biggest single hit available; only over-penetrations are damped, to ×0.10. |
| Superstructure | 19 mm primary (range 19–410 mm) | no cap | Any HE ≥16 mm pens at full damage | Any HE ≥16 mm pens at full damage. HE-spam target, and the section saturates fast (often only a few thousand HP). |
Saturation cap = HP a section can absorb before further damage to it is reduced (the "bow-tank" effect). Citadel pool is ~165k on every ship (effectively no cap); damage is gated by pen/over-pen multipliers instead. Superstructure saturates fast but HE always pens regardless of the plate thickness. Rudder (and other module HPs) are a separate pool from ship HP: damaging a module doesn't drain ship HP. Incapacitated modules like the rudder and engine are restored by DCP, but secondary and AA mounts destroyed at 0 HP stay out for the rest of the battle.
Balance updates affecting Iwami B. Cards are condensed; use each source link for full context.
Every custom exterior Iwami B can equip, from in-game data.
Filtered to official World of Warships: Legends pages where this ship is a focus, reward, line member, or high-context variant mention.