Chapter 103: Paving The Way In Advance For Dual-use In Gaoping
Whether to mass-produce 16 potentially redundant gun barrels was not a decision Lelouch could make; he naturally turned to Gustav.
Facing the eager gazes of the Naval Minister and Lelouch, Gustav immediately patted his chest:
“Krupp is willing to bear this risk! After all, it’s just adding an insurance policy to the Imperial Navy’s construction timeline. Worst case, we make 16 extra barrels that sit unused in our own stock.”
In fact, when answering this question, Gustav had already played a little trick—
He didn’t need to make any extra sacrifices at all, because 8 of those 16 barrels were nearly finished—they were originally prepared for the Baria. As for the 8 for the Baria, they had been made long ago, then repurposed into railway guns, and later another 8 were ordered to replace them. This batch wasn’t complete yet, but the steel billets had already been forged.
In other words, regardless of whether Tirpitz raised this requirement, Krupp had to finish those 16 barrels anyway. By saying this, he was simply making the client owe a little more favor.
However, Tirpitz and Lelouch didn’t know this, so Lelouch generously offered Gustav some advice on finding a buyer:
“No need to worry about that. If the old guns end up unsold, I’ll find you another buyer—whether for continuing railway guns or coastal defense guns, we can definitely ensure every heavy cannon from Krupp plays its proper role.”
Hearing this, Gustav smiled somewhat embarrassedly. He had only intended to play a bit pitiful to gain some sympathy, but Lelouch turned out to be quite sincere.
He quickly assured: “With Director Lelouch’s words, what do I have to worry about? Whatever use you come up with is surely the best.
Previously, those 8 main guns from the Baria that you converted into railway guns played the leading role in sinking the Warspite and heavily damaging the Queen Elizabeth. Without those large barrels, the Empire would have had no good countermeasures against the Queen-class at the time.”
This topic was set aside for now, and the parties formally agreed to use new main guns forged from three-phase electric arc furnace gun steel for the Baria-class battleships and even the later Mackensen-class battlecruisers.
After finishing the main gun discussion, Lelouch struck while the iron was hot, continuing to help Gustav promote more secondary guns/cruiser guns made with electric arc furnace gun steel.
Lelouch then mentioned: “Your Excellency Marshal, I believe the Imperial Navy’s 150mm cruiser guns and even battleship secondary guns can be comprehensively replanned and redesigned. Future new ships could all uniformly adopt a new firearm made from premium gun steel, or even introduce a new caliber.”
As soon as Lelouch said this, Tirpitz and Gustav immediately frowned: Changing the gun steel was one thing, but changing to a new caliber? Wouldn’t that increase logistics complexity and armament inventory?
War is all about logistics; supplies should be as simple as possible. Without necessity, how could they casually add another artillery shell caliber?
However, given Lelouch’s previous suggestions had all been good, building up historical credit, Marshal Tirpitz patiently gave him a chance to finish:
“Then tell me, what caliber of gun do you want to add? Why must these secondary guns/cruiser guns save on barrel weight and absolutely use new gun steel?”
Lelouch immediately drew on ideas he had repeatedly pondered in his previous life as a military enthusiast and spoke eloquently:
“I think the Empire can emulate the latest 140mm secondary guns on the Frankish Bretagne-class battleships and develop a similar one.
Of course, the Frankish 140 is just nominal; I precisely measured the actual caliber from an unassembled finished product seized at the Dunkirk shipyard—it’s 138.6mm, exactly 1% smaller than nominal.
We have ready seized samples on hand, plus other production equipment and data captured during the North France campaign. Building on replication, with Krupp’s technical level—or pulling in Rheinmetall—it should be easy to reverse-engineer and develop.
Hearing this, Marshal Tirpitz couldn’t help waving his hand first, signaling him to stop: “Don’t tell me first how ‘fast and easy’ this thing is to develop. What I care about first is the necessity and benefits of the research and development! If something is useless, no matter how easy it is to develop, it’s still useless!”
Lelouch immediately shifted his analysis angle: “In terms of use, a 138.6mm or 140mm gun certainly has great value, mainly in the following aspects: The Franks went to great lengths over a long time to develop this odd 138.6mm caliber precisely to repeatedly test the ‘sweet spot for the loading limit of integral shells by manpower.’
A 127mm or 5-inch gun can fully use fixed ammunition with shell and charge bag integrated; anything smaller like 105mm is even easier. That’s why, whether naval guns or land cannons, 105 or 127 have much higher rates of fire than 150mm and above heavy guns—at least twice as fast.
At the 150mm level, just the shell weight without the charge bag is around 60kg or even heavier; adding the charge bag and packaging, it approaches 80kg. We can’t recruit enough strong sailors to repeatedly lift 80kg loads single-handedly and operate without error continuously.
The 140mm caliber is the ‘sweet spot’ the Franks arrived at after repeated testing—the maximum limit caliber for ‘a robust sailor to repeatedly handle integral fixed shells combining warhead and propellant.’
Previously, countries chose 105/127/152mm calibers just to hit integer inches, for convenience, not because it was physically more rational.”
Tirpitz and Gustav could understand these principles; after all, the Franks had thought about this for years, and as opponents, they would generally study the enemy’s naval armament planning philosophy.
But the Germania Navy has always been efficiency- and accuracy-focused; Tirpitz has never liked high-speed splashy firing, so he frowned and said:
“But is there a need to pursue rate of fire to such an extreme? The current secondary gun rate of fire is sufficient, and flexibility is enough. Shrinking from 150 to 140 would lose power, armor penetration, and maximum range. Moreover, the Empire’s 150mm is the best in the world; there’s no reason to abandon the existing advantage.
The Empire’s 150mm secondary guns are for sniping enemy light high-speed torpedo boats from over 10,000 meters. Shells take over 10 seconds to fly that distance; for guns firing over 6 rounds per minute, at that range, it doesn’t mean much—the previous round hasn’t landed before the next is fired, and errors can’t be corrected in time.”
Lelouch of course knew Marshal Tirpitz was right, so he had no intention of directly refuting; instead, he thought of another application scenario for him, opening everyone’s minds:
“But, respected Your Excellency Marshal, have you considered that the future application scenarios for secondary guns and cruiser guns will differ from now? Airplanes have appeared; though they lack strong ground/sea attack capability yet, their long-term development trend cannot be underestimated.
Half a year ago, airplanes couldn’t even engage in aerial combat with machine guns, but now they can. Pilots can manually drop 5kg single bombs from below; in the future, adding a simple release mechanism will allow dropping dozens of kg or even heavier bombs without issue.
The Empire’s airship force even executed 2 Britannian pre-dreadnoughts beached on the sand with 2000kg aerial bombs in the De Panne naval battle. All this foreshadows that future battleships will face increasingly severe air threats.
150mm secondary guns, due to overly heavy shells requiring separate warhead and charge bag loading, can’t achieve high rate of fire, and traverse slowly—doomed to be inefficient for anti-air.
But shrinking to 140mm caliber level, using specialized anti-air shrapnel/fragmentation shells in the future, effective fragments can increase by half over 127mm guns, kill radius over 20%, and with time fuzes for anti-air, it will definitely yield twice the result with half the effort.”
Using his transmigrator understanding of future anti-aircraft guns, Lelouch depicted the “dual-purpose high/low angle” concept to Tirpitz and others, successfully provoking deep thought.
“This is for future anti-air threat needs? That does make some sense; long-range anti-air should indeed be emphasized…” Tirpitz couldn’t help muttering to himself, quite moved.
In fact, Lelouch had held back one consideration—he knew that if focusing on radio technology in the future, miniaturizing and cheapening radio passive detection devices could produce VT radio proximity fuzes.
Historically, Germania secondary guns were disadvantaged in dual-purpose use partly because 105mm caliber was too small; after fitting radio proximity fuzes, they took too much space, leaving little room for fragments and explosives, making anti-air efficiency extremely poor.
150mm couldn’t rapid-fire anti-air due to separate loading. Ultimately, the Ugly Country’s 127mm dual-purpose gun became the king in the radio proximity fuze era.
Historically, Germania never emphasized 127mm-level guns; their land cannons jumped straight from 105 to 150, unlike infantry’s ~127mm 60-pounder guns or the Eastern Front Lusha Army’s 122mm guns.
In naval terms, during the Great War, Germania had no destroyer concept—only “large torpedo boat”-style so-called destroyers with 88mm main guns like submarine guns. Then light cruisers jumped straight to 150mm; light cruisers had 105mm secondary guns, but “large torpedo boats” didn’t use them.
This led to Earth history’s WWII era producing some “destroyers” with a few 150mm main guns—strictly by main gun caliber, they shouldn’t count as destroyers but light cruisers, just without light cruiser endurance and operational range.
So from this angle, Lelouch proposing Marshal Tirpitz decisively develop a 140mm or 138.6mm gun based on Frankish seized goods was actually very cost-effective.
For other countries that already had 127mm, adding 140mm would be redundant construction. But Germania didn’t have 127mm yet, so no waste. （Germania’s later 127mm was actually 128mm, with twin 128mm heavy anti-air guns and Hunter Tiger’s 128mm anti-tank gun）
In the future, forget 127/128mm entirely; just add 10mm to 140mm, hitting near the “sweet spot” for “maximum weight of manually loaded integral ammunition.”
Future naval 150mm and 105mm could both be absorbed by 140mm. Or keep one of 105mm and 88mm levels specifically for high-speed torpedo boats or mid-range anti-air supplement. But once Bofors 40mm guns arrive, 88mm guns on warships won’t have much value.
……
Lelouch’s vision of caliber consolidation and dual-purpose anti-air finally convinced Marshal Tirpitz.
After weighing it repeatedly, he made this epochal decision: No shame in learning from the Franks—start with their seized 138.6mm actual items and data to develop Germania’s own 140mm gun!
No more new 150mm on warships henceforth, nor developing 128mm.
In the future, if emulating Britannians for large, formal destroyers, they could directly mount 140mm main guns. Distinction between destroyers and light cruisers needn’t be by main gun caliber—could just be protection, operational radius, fire density.
Large destroyers have short range, small hulls, only one forward and one aft 140mm turret, but similar torpedo capability.
Light cruisers have long range, long hulls, slightly stronger protection, can mount more 140mm turrets as main force for scouting and sweeping enemy torpedo formations.
Seeing he had finally convinced Marshal Tirpitz, Lelouch seized the chance to add some details:
“Your Excellency Marshal, since the Empire has decided on 140mm secondary guns/cruiser guns, perhaps we can make some tweaks to currently building and future-designed battleships.
Current secondary guns are all casemate-style, on dedicated casemate decks, mainly able to traverse left/right with severely limited elevation.
For future dual-purpose high/low angle use, secondary guns must all become turret-style. Directly making 150mm secondary guns into turrets would be troublesome, as same-caliber turret guns definitely take more space and tonnage than casemate guns, hard to adjust.
But since we’re shrinking the gun caliber by at least 10mm, the guns themselves take much less tonnage and volume. I estimate converting original 2 single 150mm casemate guns to 1 twin 140mm turret is feasible in volume and total weight. If deciding, decide early now to avoid major refits on other battleships later.”
After hearing this, Tirpitz first glanced at Gustav, who immediately stated: “Krupp is confident in producing 1 twin 140mm within the reserved volume and weight of the original 2 single 150mm casemate guns. But hull design and construction aren’t our call—it’s up to William Shipyard and relevant design bureaus.”
Tirpitz was very knowledgeable and could accurately assess those units’ design capabilities. After pondering, he gave a prudent compromise:
“Then leave Baria and Baden untouched for now—definitely no time; after the war ends, modernize if needed, reserving refit potential.
The latter 3 of Baria-class haven’t fully completed hulls; remove the topmost casemate deck to save space for direct 140mm twin secondary turrets—but don’t drop the ball at Krupp; remember to pre-estimate dimensions and tonnage for the 140mm twin dual-purpose turrets with margin, inform William Shipyard design bureau, so projects can advance in parallel.
Your reported tonnage and size specs can only be smaller than actual when built, never larger—otherwise, if it overruns and won’t fit, you’re accountable.”
Gustav quickly agreed, saying everything was on him.
——
PS: Originally planned to post the second update after class this afternoon, but finished it before morning class. So there it is.
