The code block of text is from ships.ini in BAT 4.0. The "strength_HullEnorm" is the highest strength besides Invulnerable. You could look in your vp modpack ships.ini file and see what strength is applied there.
// USS 'Missouri' (BB-63)
[USSMissouriBB63]
Description USS Iowa Class Battleship 'Missouri' (BB-63)
Icon shipDestroyer
// Model
Mesh 3do/Ships/USSMissouriBB63/Hier.him
// Motion Parameters
SliderDistance 567.675
Speed 50.0 //TASK FORCE
SoundMove models.Ship
IsAirport 1
//Vitals
[USSMissouriBB63:Part0]
BaseChunk Hull01
strengthBasedOnThisSection strength_HullEnorm
Vital
damageDepth 0.4
damagePitch -2.0
damageRoll 4.0
damageTime 164.0
[USSMissouriBB63:Part1]
BaseChunk Hull02
strengthBasedOnThisSection strength_HullEnorm
Vital
damageDepth 0.4
damagePitch -2.0
damageRoll 4.0
damageTime 164.0
[USSMissouriBB63:Part2]
BaseChunk Hull03
strengthBasedOnThisSection strength_HullEnorm
Vital
damageDepth 0.4
damagePitch -2.0
damageRoll 4.0
damageTime 164.0
[USSMissouriBB63:Part3]
BaseChunk SST01
strengthBasedOnThisSection strength_HullEnorm
[USSMissouriBB63:Part4]
BaseChunk SST02
strengthBasedOnThisSection strength_HullEnorm
I don't know if there might be some other difference between game versions, such as whether different TNT values, etc., are employed as well. I include the 4.12.2 the Gun and Hull durability values table, which seems to be not present in my BAT 4.0 ships.ini...
[strength_GunTiny]
MinShotCaliber 0.00762
NumShots 30
MinHitExplTNT 2
NumHitExpl 4
MinNearExplTNT 4
NumNearExpl 4
[strength_GunSmall]
MinShotCaliber 0.0127
NumShots 40
MinHitExplTNT 4
NumHitExpl 4
MinNearExplTNT 8
NumNearExpl 4
[strength_GunMedium]
MinShotCaliber 0.02
NumShots 50
MinHitExplTNT 6
NumHitExpl 6
MinNearExplTNT 12
NumNearExpl 6
[strength_GunLarge]
MinShotCaliber 0.037
NumShots 82
MinHitExplTNT 8
NumHitExpl 8
MinNearExplTNT 16
NumNearExpl 8
[strength_GunHuge]
MinShotCaliber 0.045
NumShots 90
MinHitExplTNT 12
NumHitExpl 12
MinNearExplTNT 24
NumNearExpl 12
// Hull Durability
[strength_HullTiny]
MinShotCaliber 0.00762
NumShots 80
MinHitExplTNT 2
NumHitExpl 5
MinNearExplTNT 4
NumNearExpl 5
[strength_HullSmall]
MinShotCaliber 0.02
NumShots 84
MinHitExplTNT 4
NumHitExpl 12
MinNearExplTNT 8
NumNearExpl 12
[strength_HullMedium]
MinShotCaliber 0.030
NumShots 106
MinHitExplTNT 10
NumHitExpl 12
MinNearExplTNT 20
NumNearExpl 12
[strength_HullSub]
MinShotCaliber 0.030
NumShots 106
MinHitExplTNT 10
NumHitExpl 12
MinNearExplTNT 20
NumNearExpl 12
[strength_HullLarge]
MinShotCaliber 0.05
NumShots 118
MinHitExplTNT 12
NumHitExpl 25
MinNearExplTNT 24
NumNearExpl 25
[strength_HullHuge]
MinShotCaliber 0.1
NumShots 92
MinHitExplTNT 20
NumHitExpl 25
MinNearExplTNT 40
NumNearExpl 25
[strength_HullEnorm]
MinShotCaliber 0.203
NumShots 148
MinHitExplTNT 40
NumHitExpl 25
MinNearExplTNT 80
NumNearExpl 25
[strength_Invulnerable]
MinShotCaliber 0.203
NumShots 1000
MinHitExplTNT 1000
NumHitExpl 1000
MinNearExplTNT 1000
NumNearExpl 1000
As we can see here, for a hull section of "strength_HullEnorm", it requires a direct hit of 40kg of TNT to even begin to do damage, and it further requires 25 such hits to cause failure. I don't know how to extrapolate this to a larger charge and the resulting numbers of those hits to cause destruction. Bear in mind that ships tend to be structured such that there are three hull sections, roughly equally divided along the length. To assess numbers of hits necessary to destroy a section, concentrate on one at a time.
You could also skip 500kg or 1000kg bombs into a particular section (bow, amidships or stern), and see how many of those are required to set that section afire/smoking.