Q-Eng

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パナマ運河は3か所の閘門と人工湖を利用した運河。年間 約 1.4万隻（１日約40隻）｡
全長82km、許容船幅49m、海抜26m、通過は平均.9時間。（待ちを含むと24時間）
閘門での船舶の上昇下降は湖水を順次落とすだけ。（最近は干ばつで危機傾向）。
1881年フランスが最初.海面式､後に閘門式で建設したが1889年に挫折。その後米国の
政治介入があり、閘門式で建設され、1914年に正式に開通した。（建設期間.10年）

易　５分　135wpm　　　　　　　　　　　　　　　　　　　　　　　　　　2021年

字幕 ： 開始後 で字幕On/Off､ で言語選択。文字の色やサイズﾞはｵﾌﾟｼｮﾝから｡
.　　　　 動画を見るとき、 でフルスクリーンに拡大すると見やすい。

★下記英文は ポップアップ辞書 が使えます｡
　　テキストはこちら⇒日英トランスクリプト （字幕はYouTubeの方が大きく見やすい）　　　　　　　　

In the middle of the 19th century, the California gold rush brought thousands of settlers to America’s west coast. But finding gold may have been easier than transporting it back east. The only hope for avoiding a grueling six month wagon journey was to travel the narrowest portion of the continent— the 48-kilometer Isthmus of Panama.

By 1855, a railroad spanning the region significantly shortened to the trip, but unloading and reloading ships at each port cost time and money. To truly connect these two bodies of water shipping interests needed a canal— a continuous maritime passage through the isthmus（地峡）.

The first attempt at this colossal construction project was taken up in 1881 by French diplomat Ferdinand de Lesseps. De Lesseps had supervised construction of Egypt's Suez Canal, but his success made him overconfident. He insisted on digging the canal at sea level, even though it required boring directly through the Continental Divide mountain range.

Futile excavation efforts were buried under constant landslides. And since the diplomat had only visited the site briefly during Panama’s dry season, his workers were unprepared for torrential storms, venomous jungle fauna, and tropical diseases. After spending $287 million and losing a staggering 22,000 lives, the French abandoned the project.

The United States had been considering building a canal through Nicaragua, but at this point, the chance to succeed where France failed was tempting. Panamanian leaders were also eager to complete a canal which would bring their country business and prestige. However, Panama was still a part of Colombia at the time, and the country was stalling negotiations with the U.S.

Sensing an opportunity, President Teddy Roosevelt went straight to the Panamanians. With encouragement and military support from the U.S., Panama launched a coup in 1903. Within days, they became an independent nation and signed a treaty to begin construction of the canal.

Just over a decade after the French left, the Americans were ready to dig in— and they were determined to avoid their predecessor’s mistakes. Instead of cutting the mountain down to sea level, they would raise the sea up the mountain.

The plan was to build massive steel gates separating the canal into multiple chambers with different water levels. As a ship passed through each successive gate would open, lowering the water level in the next chamber, while raising the ship and allowing it to move on.

The design called for five of these so-called canal lock（閘門）ｓ. — three on the Atlantic side and two on the Pacific, raising traversing ships 26 meters above sea level. Operating this lock system would require a massive reservoir of water.

And fortunately, the low-lying Chagres river valley provided a natural solution. By building a dam across the gap where the river flowed out to sea, the entire valley could be flooded. At 32 meters high and over 800 meters wide, the Gatun Dam would be larger than any built before.

With this innovative plan, the Americans didn’t need to excavate the entire mountain, but rather, just the pathway for the canal itself. Still, the work was staggering. Even after progress made by the French, it took over nine years for 24,000 workers to blow up, shovel, and drill out the Culebra Cut— a roughly 14 kilometer passageway through the Continental Divide. The railway, now upgraded and rerouted to follow the canal, carted away over 76 million cubic meters of excavated rock to be used at the Gatun Dam site.

Construction was only half the battle. Leading army officials struggled to maintain infrastructure and sanitation, but accidents and diseases took the lives of 5,000 workers— mostly Black Caribbean migrants. Then, in the fall of 1913, the moment finally came. A telegraph signal from President Woodrow Wilson triggered a dike explosion, flooding the Culebra Cut and joining the Atlantic and Pacific Oceans.

Today, nearly 14,000 vessels travel through the isthmus annually— each in under 12 hours. The canal remains Panama’s chief source of revenue; and since the country gained ownership of the passage in 1999, it has also become a source of national pride.