Shbb

[Makje]

it is actually quite easy to mod that. If you have TFH, go into the Hearts of Iron 3\tfh\technologies folder and open Naval Technologies.txt

You gotta mod the 3 battleship techs to add the super_heavy_battleship value. for example

battleship_armour = {
	battleship = {
		hull = 0.10
	}
	
	allow = {
		battleship_technology = 1
	}
 

	research_bonus_from = {
		naval_engineering = 0.3
		capitalship_practical = 0.6
		fleet_in_being_doctrine = 0.1
	}
	
	on_completion = naval_engineering

	difficulty = 3
	start_year = 1918
	first_offset = 1934	#2nd model is from 1936
	additional_offset = 2	#one new every 2 year
	max_level = 12
	folder = capitalship_folder
	can_upgrade = no
}

becomes

battleship_armour = {
	battleship = {
		hull = 0.10
	}
	
	super_heavy_battleship = {
		hull = 0.10
	}

	allow = {
		battleship_technology = 1
	}
 

	research_bonus_from = {
		naval_engineering = 0.3
		capitalship_practical = 0.6
		fleet_in_being_doctrine = 0.1
	}
	
	on_completion = naval_engineering

	difficulty = 3
	start_year = 1918
	first_offset = 1934	#2nd model is from 1936
	additional_offset = 2	#one new every 2 year
	max_level = 12
	folder = capitalship_folder
	can_upgrade = no
}

That does leave you with a too powerrfull SHBB because the 38 startingtech of SHBB allready has 3 upgrade cycles built in.
So to be correct you have to allso modify Hearts of Iron 3\tfh\units\super_heavy_battleship.txt and lower its hull, range, speed and sea and convoy attack values.

Now your SHBB will upgrade just like BB. Offcourse like all other ships this doesn't upgrade hull, guns and engines of allready build SHBB's.