pacific the Americans make a puzzling discovery.

在1945年8月 正當世界慶祝著第二次世界大戰結束時

The US Navy has intercepted a Japanese submarine and it's unlike anything

美國在太平洋地區發現了令人費解的事情

they've seen before.

美國海軍已經攔截了一艘日本潛艇 這與他們所見過的潛艇完全不同

Its scale is baffling.

它的大小令人感到困惑。

But not only is it the world's largest submarine, it's an entirely new kind of weapon.

它不僅是世界上最大的潛艇

A submarine that can launch torpedo dive bombers.

而且還是一種全新的武器

The American's have just stumbled across Japan's secret underwater aircraft carriers,

一艘可以起降魚雷轟炸機的潛艇

and soon they'll uncover a sinister plan that could've changed the

美國人才偶然發現日本的機密航空潛艦

course of the war.

接著就揭開了個可能改變戰爭走向的陰險計畫

Japan's surprise attack on Pearl Harbor in December 1941 is an event that

伊400型 航空潛艦

galvanizes a nation.

夏威夷, 珍珠港 1941年12月7日

Pulling a reluctant America into the Second World War.

在1941年12月，日本對珍珠港的偷襲

“The unprovoked and dastardly attack by Japan on Sunday...”

是件轟動了整個國家的事件。

A day after the devastating attack, the United States declares war on Japan.

將不甘願的美國拉進第二次世界大戰

And the nation quickly mobilizes, firing up its enormous industrial might to crank out

“日本在周日無端和無恥的攻擊……”

ships, tanks and aircraft at a rate that'll soon bury Japan's military.

在毀滅性的攻擊發生的隔天 美利堅合眾國對日本宣戰

For the Americans, Pearl Harbor was a senseless and cowardly provocation.

接著國家迅速開始動員

But for the Japanese, the attack was something entirely different.

啟動了它龐大的工業力量 來生產船艦、坦克、和飛機

A calculated gamble and a long shot attempt at actually trying to avoid a full-scale war

並以一個不用多久就能淹沒日本軍隊的產能運作。

with the United States.

對於美國人來說 珍珠港的襲擊是懦夫毫無意義的挑釁

Because as the Empire of Japan continued its ruthless conquest in Asia, the Japanese were

但是對於日本人來說 這場襲擊是完全不同的

convinced that it was only a matter of time before the U.S. intervened.

這是個經過精心計算的賭博

And the architect behind the Pearl Harbor attack, Japanese Admiral Yamamoto was aiming

試圖避免與美國進入全面戰爭的長遠計畫

to knock out much of the U.S Pacific fleet in one decisive blow.

因為隨著日本帝國持續無情擴大在亞洲的征服

As a way to keep the United States out of the Pacific for at least another six months

日本人相信美國會干預只是時間問題

and perhaps even forcing the Americans into negotiating a truce.

還有珍珠港襲擊背後的計畫者

But Imperial Japan grossly underestimated America's resolve.

日本的山本五十六海軍大將

And in the aftermath, Yamamoto knew America's military might would soon overwhelm Japan's.

打算一口氣消滅美國太平洋艦隊的大多數戰力

Now faced with a war he cannot win, Yamamoto devises another strategy.

透過這種方式令美國放棄太平洋海域至少六個月

To make America reconsider a drawn out war in the Pacific, He'll bring the war directly

也許甚至能強迫美國人進入停戰談判

to America's Cities.

但是日本帝國嚴重低估了美國的決心

But with the United States now on guard for Japanese forces, Yamamato will need a truly

在這之後，山本知道美國的軍事力量 很快就能壓垮日本

stealthy weapon to reach the United States.

面對一場他無法戰勝的戰爭， 山本想了另一種策略

A weapon the Americans would never suspect.

讓美國重新考慮取消在太平洋上的戰爭

The concept of launching aircraft from a submarine originated before the Second World War.

他將直接把戰爭帶往美國各城市

But these earlier attempts were experimental trials usually involving a single lightweight

但是隨著現在美國警惕著日軍

reconnaissance plane.

山本需要個真正能隱形到達美國的武器

What Yamamoto had in mind was far more ambitious.

一個美國人永遠猜不到的武器

A fleet of submarines that could carry multiple attack aircraft and strike fear into the enemy

從潛艇發射飛機的概念 起源於第二次世界大戰之前。

by launching surprise attacks on cities, only to submerge and disappear again

但是這些較早的嘗試是實驗性的 通常只搭載一架輕量的試驗偵察機

In March of 1942, Japanese engineers were handed the enormous task of designing Yamamoto's

山本的想法遠遠比這更有野心

secret weapon.

一支可以攜帶多架攻擊機的潛艇艦隊

To start, Yamamoto's aircraft carrying subs would need to be capable of launching full-size

對城市發動突襲並向敵人散布恐懼

torpedo dive-bombers.

之後再度下潛消失

And engineers would have to design a catapult launching system.

1942年3月，日本工程師 承接了設計山本秘密武器的巨大任務

And a mechanism to recover the aircraft and bring them back onboard.

首先，山本的載機潛水艇 需要能夠發射全尺寸的魚雷轟炸機

But making the bombers fit inside a submarine would be an even bigger challenge.

工程師必須設計個彈射器發射系統

With a typical World War Two-era dive bomber having a wingspan of about 12 meters, engineers

還有一種回收飛機的裝置

would also need to design an entirely new dive bomber.

並將它們回收到船上

One that could be folded up to fit inside the sub's hanger.

但要將轟炸機放進一艘潛艇

The submarines would also need to be able to reach any part of America's coastline,

將會是個更大的挑戰。

thousands of kilometers away.

在二次世界大戰時期的俯衝轟炸機翼展約12公尺

And then return all the way back to Japan without refueling or resupplying.

為此，工程師還需要設計一架全新的轟炸機。

And it meant carrying nearly two million liters of diesel fuel and enough supplies to support

一架可以摺疊並放進潛艇機庫的轟炸機

a crew out at sea for months.

潛艇還需要能夠到達美國海岸線的任何地方

Japan's secret underwater aircraft carriers would be designated as the I-400.

或幾千公里之外， 然後無需加油或補給一路回到日本

And they'd be enormous.

這意味著要攜帶近200萬公升的柴油

Nearly twice the length of a typical German U-boat.

和足夠的補給來讓船員在海上支撐好幾個月

To support the weight of the hanger and to keep the sub stable during carrier operations,

日本的機密水下航空母艦將被命名為伊400

engineers innovated a double hull design.

而且它們將是巨大無比的 長度幾乎是典型德國U型潛艇的兩倍大

Essentially two hulls stuck together.

為了能夠支撐機庫的重量及潛艇航行時的穩定性

It gave the mammoth I-400 nearly three times the displacement of even the largest

工程師創新設計了雙船體結構

American submarine.

基本上，就是將兩個船體黏在一起

And the I-400 was still a formidable submarine in the conventional sense.

它讓龐大的伊400和美國最大潛艇 排水量相比下有將近三倍之大

Armed with eight forward mounted torpedo tubes and a massive deck gun.

伊400在傳統設計來說仍是一艘厲害的潛艇

And to fend off enemy aircraft, three triple-mounted anti-aircraft guns and a fourth single mounted

配備了八個前置魚雷發射管

gun on the sail.

和一門巨大的14cm甲板砲

But of course the i400's primary weapons were its three torpedo dive bombers.

為了抵​​禦敵機

The element of surprise was an underwater aircraft carrier's greatest advantage.

還有三聯裝高射砲三座及單裝砲一挺

And as the I-400 silently approached its target, its crew would already begin preparing the

當然，伊400的主要武器是三架魚雷轟炸機

aircraft.

奇襲的特性是水下航空母艦的最大優勢

Mechanics would start by running heated oil through the aircraft's engines so they would

當伊400默默地接近其目標時

be warmed up and ready to launch.

它的船員早就開始整備飛機

The mammoth submarine would surface a few hundred kilometers from its target and the

技師會將加熱過的油注進飛機的引擎

race would be on to get three bombers airborne.

讓它們暖機並準備發射。

Each aircraft would be rolled out from the hangar onto the deck.

這艘巨大的潛水艇約距離目標約幾百公里時浮出水面

Crews would then start the engine, unfold the wings and tail, lock floats into place,

三架轟炸機將如競賽般的升空

and load armament.

每架飛機將從機庫移至甲板上

One by one, the three aircraft would be launched using a compressed air catapult.

接著，機組人員會啟動引擎、展開機翼和尾翼， 將浮桶鎖定到位和裝載武器

The whole process would take thirty minutes.

三架飛機將使用壓縮空氣彈射器依序發射

After which the I-400 would dive back to safety and silently wait for the bombers to return

整個過程將花費三十分鐘

from their mission.

在那之後，伊400將會下潛回安全區

The torpedo dive bombers were cutting edge.

並安靜地等待轟炸機完成任務返回

They were designed specifically for the I-400 and could carry the largest bomb or torpedo

這種魚雷轟炸機在當時非常先進(註:晴嵐攻擊機)

in Japan's naval arsenal.

它們是專門為伊400設計的

Equipped with floats, the aircraft would land alongside the submarine to be hoisted back

可以攜帶日本軍隊最大的炸彈或魚雷

aboard using a collapsible hydraulic crane.

裝備浮桶的飛機會降落在潛艇旁

The aircraft could also be launched without floats for greater range and performance,

等待被可折疊的液壓起重機回收至船上

but forcing pilots to ditch into the ocean after their mission.

該飛機也可以在沒有浮桶的狀況下彈射， 以獲得更遠的航程和更好的性能

The I-400 was a brilliant design, merging the stealth of a submarine with the offensive

但這會卻迫使飛行員在完成任務後墜入大海

strike capability of an aircraft carrier.

伊400是個出色的設計

But Japan's new super weapon would make no difference in the War.

結合了潛艇的隱身特性 及航空母艦的進攻打擊能力

On August 15, 1945, after nearly four years of brutal conflict and with American forces

但是日本的新超級武器將不會對戰爭帶來任何改變

closing in and the bombing of Japanese cities, Japan finally surrendered.

於1945年8月15日 在與美軍發起慘烈的衝突將近四年後

The Americans first intercepted an I-400 off the coast of Japan two weeks after the surrender.

因步步逼近的美軍 及受到轟炸的日本都市

And at first they weren't exactly sure what it actually was.

日本最終投降了

The Japanese crew had thrown all of the attack aircraft overboard.

首先美國人在日本投降兩週後

And at first the Americans believed the I-400 was designed to carry cargo.

在日本海岸攔截了一艘伊400型潛艇

But they'd soon unravel the submarine's true purpose and why Japan never used them

一開始，他們太不確定它是什麼東西

in the War.

日本船員已將所有的攻擊機丟下潛艇

To start, many in Japan's Navy considered Yamamoto's underwater aircraft carriers

最初，美國人相信伊400是被設計用來運載貨物的

to be a farce.

但很快，他們就會揭開潛艇的真正用途

And the slow process of launching aircraft in the middle of a combat zone too dangerous

以及日本為何從未在戰爭中使用過它們

for submarine crews.

首先，許多日本海軍的人認為 山本的水下航空母艦是一場鬧劇

But resistance to the concept would soon be the least of Yamamoto's concerns.

以及太過於緩慢的飛機發射過程

Because it took nearly a year to design such an unconventional weapon.

還有在交戰區中對於潛艇人員過於危險

Construction of the first I-400s only began at the start of 1943.

但這些對於構想的反對聲浪 對於山本來說並不是他的主要擔憂

By then, the Japanese were already losing the War.

因為設計個這樣的非常規武器花了將近一年的時間

After a crushing defeat in June of 1942, the Americans were pushing the Japanese back across

第一批伊400在1943年初才開始建造

the pacific.

在那時，日本在戰爭已處於劣勢

And Japan was running critically short on fuel and raw materials.

在1942年6月中途島海戰慘敗後

Delaying I-400 construction even further.

美國人把日本人推回太平洋的另一端

And Yamamato himself would never live to see any of his submarines completed.

並且，日本在那時嚴重缺乏原油和原物料

In 1943, while on an inspection tour through the South Pacific, Yamamoto's plane was

更加延後了伊400的建造

downed by American forces.

而且山本本人無法活著看到 他的任何潛艇完工

What started as a plan to build a fleet of eighteen underwater aircraft carriers was

在1943年，在南太平洋巡視時

eventually whittled down to just five.

山本所乘坐的飛機被美軍擊落

And only three were ever completed.

建立一支18艘水下航母艦隊的計畫

The first entering service in 1945.

最終縮編到只有5艘

So late in the War that Japan's military had already all but collapsed.

然而只有3艘完工

Launching sneak attacks on American cities with a handful of dive bombers would've

第一艘在1945年首次服役

been pointless.

但處於戰爭後末期 日本軍隊早已經崩潰了

Even a more strategic mission to bomb the Panama Canal was abandoned after Japanese

用幾架轟炸機向美國城市發起偷襲

command felt that it too would've made little difference so late in the War.

幾乎毫無意義

The only mission the I-400's would ever set out on was a last ditch effort to bomb

甚至更具戰略意義的巴拿馬運河轟炸任務

American forces as they amassed off a tiny pacific atoll.

也因日本指揮官認為這任務在戰爭末期

But as the first I-400s traveled to their targets, Japan surrendered, finally ending

能造成影響微乎其微而被取消

the Second World War.

伊400的第一次且是最後一次的任務

Aircraft carrier submarines had always been a gamble.

是轟炸一個聚集在 太平洋環礁上的美軍部隊

A way to change odds so stacked against Japan, that only through sheer ingenuity could the

但是當第一批伊400前往他們的目標時

tables be turned.

日本就投降了

And had the sub arrived at the start of the war it might've made a difference.

終於結束了第二次世界大戰

But Japan's secret weapon wasn't without compromise.

航空潛艦一直以來都是場賭博

The process of launching three aircraft was supposed to take 30 minutes.

一種改變對日本的賠率的方法

But rarely could it be accomplished in less than 45.

只有通過獨創性才能將盤局翻轉

A dangerous amount of time for such a large submarine to be surfaced.

如果讓這些潛艇在戰爭開始時出現 這可能會讓大局有所不同

And the I-400's bombers, while sophisticated in their design were rushed into service and

但是日本的秘密武器 並非沒有碰到不順利的狀況

built from lower grade materials due to shortages.

發射三架飛機的作業 原本只該花上30分鐘

They were notoriously unreliable.

但實際上很少能在45分鐘內完成

Rarely could all three get airborne without some mechanical problem.

如此巨大的潛艇 在那麼長的時間下浮出水面相當危險

And the enormous I-400's depth time, critical for getting out of danger, was nearly double

加上伊400的轟炸機 設計複雜又被倉促的投入使用

that of American submarines.

且基於原物料短缺而使用次等原料

Even submerged, it was still vulnerable.

他們有著臭名昭著的妥善率

With a hull that was riveted, not welded, it likely would have stood up poorly against

要三架飛機都不發生機械問題並升空非常少見

depth-charges.

而且巨大的伊400緊急下潛 所需的時間得花費近美國潛艇的一倍

Still, the Americans considered the I-400 to be a dangerous weapon.

即使下潛時，它仍然是非常脆弱的。

Especially in the wrong hands.

用鉚釘連接而不是焊接的船體

And In 1946, with the Soviets demanding to inspect the subs for themselves, the American's

讓它可能無法有效的對抗深水炸彈

scuttled the I-400s off the coast of Hawaii and Japan.

儘管如此，美國人認為伊400還是個危險的武器

Keeping their exact wreckage locations secret, and closing the chapter on an ambitious new

特別是在落在錯的人手裡

kind of weapon, that in a different set of circumstances, might've changed the course

在1946年，蘇聯要求自行檢查潛艇

of the war.

於是，美國人在夏威夷及日本海岸附近鑿沉了伊400

This video originally appeared on Nebula.

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在某些狀況下可能可以改變整個戰爭的局面

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