Hell Gate

The excavations and tunnels used to undermine Hallert's Point

Periodically, merchants and other interested parties would try to get something done about the difficulty of navigating through Hell Gate. In 1832, the New York State legislature was presented with a petition for a canal to be built through nearby Hallet's Point, thus avoiding Hell Gate altogether. Instead, the legislature responded by providing ships with pilots trained to navigate the shoals for the next 15 years.[12]

In 1849, a French engineer whose specialty was underwater blasting, Benjamin Maillefert, had cleared some of the rocks which, along with the mix of tides, made the Hell Gate stretch of the river so dangerous to navigate. Ebenezer Meriam had organized a subscription to pay Maillefert $6,000 to, for instance, reduce "Pot Rock" to provide 24 feet (7.3 m) of depth at low-mean water. While ships continued to run aground (in the 1850s about 2% of ships did so) and petitions continued to call for action, the federal government undertook surveys of the area which ended in 1851 with a detailed and accurate map.[12]

By then Maillefert had cleared the rock "Baldheaded Billy", and it was reported that Pot Rock had been reduced to 20.5 feet (6.2 m), which encouraged the United States Congress to appropriate $20,000 for further clearing of the strait. However, a more accurate survey showed that the depth of Pot Rock was actually a little more than 18 feet (5.5 m), and eventually Congress withdrew its funding.[13]

With the main shipping channels through The Narrows into the harbor silting up with sand due to littoral drift, thus providing ships with less depth, and a new generation of larger ships coming online – epitomized by Isambard Kingdom Brunel's SS Great Eastern, popularly known as "Leviathan" – New York began to be concerned that it would start to lose its status as a great port if a "back door" entrance into the harbor was not created.[14] In the 1850s the depth continued to lessen – the harbor commission said in 1850 that the mean water low was 24 feet (7.3 m) and the extreme water low was 23 feet (7.0 m) – while the draft required by the new ships continued to increase, meaning it was only safe for them to enter the harbor at high tide.[15]

The U.S. Congress, realizing that the problem needed to be addressed, appropriated $20,000 for the Army Corps of Engineers to continue Maillefert's work, but the money was soon spent without appreciable change in the hazards of navigating the strait. An advisory council recommended in 1856 that the strait be cleared of all obstacles, but nothing was done, and the Civil War soon broke out.[16]

The 1885 explosion

In the late 1860s, after the Civil War, Congress realized the military importance of having easily navigable waterways, and charged the Army Corps of Engineers with clearing Hell Gate of the rocks there that caused a danger to navigation. The Corps' Colonel James Newton estimated that the project would cost $1 million, as compared to the approximate annual loss in shipping of $2 million. Initial forays floundered, and Newton, by that time a general, took over direct control of the project.[16] In 1868 Newton decided, with the support of both New York's mercantile class and local real estate interests, to focus on the 3-acre (1.2 ha) Hallert's Point Reef off of Queens. The project would involve 7,000 feet (2,100 m) of tunnels equipped with trains to haul debris out as the reef was eviscerated, creating a reef structured like "swiss cheese" which Newton would then blow up.

After seven years of digging seven thousand holes, and filling four thousand of them with 30,000 pounds (14,000 kg) of dynamite, on September 24, 1876, in front of an audience of people including the inhabitants of the insane asylum on Wards Island, but not the prisoners of Roosevelt Island – then called Blackwell's Island – who remained in their cells, Newton's daughter set off the explosion. The effect was immediate in decreased turbulence through the strait, and fewer accidents and shipwrecks. The city's Chamber of Commerce commented that "The Centennial year will be for ever known in the annals of commerce for this destruction of one of the terrors of navigation." Clearing out the debris from the explosion took until 1891.[17][18][19][20]

Newton had begun to undermine Flood Rock, a 9-acre (3.6 ha) reef, even before starting on Hallert's Rock, removing 8,000 cubic yards (6,100 m³) of rock from the reef. In 1885 Flood Rock was blown up as well,[21] with Civil War General Philip Sheridan and abolitionist Henry Ward Beecher among those in attendance. Newton's daughter once more set off the blast, the biggest ever to that date and subsequently reported as the largest man-made explosion until the advent of the atomic bomb[17][18][19] although the detonation at the Battle of Messines in 1917 was several times larger. Two years later, plans were in place to dredge Hell Gate to a consistent depth of 26 feet (7.9 m).[22]

• Hell Gate: The Watery Grave (1977), is a 50-minute documentary film, narrated by Alexander Scourby, which covers many aspects of the waterway's history, including the clearing of the channel, the building of Hell Gate Bridge, and the PS General Slocum steamship disaster.
• Under Hellgate Bridge (1999), directed by Michael Sergio, is a crime drama/thriller film, set in Queens, that features the bridge.[23]
• Gangs of New York (2002), directed by Martin Scorsese; the main character, Amsterdam Vallon (Leonardo DiCaprio), is sent to Hell Gate Orphanage as a child upon the death of his father

In James Fenimore Cooper's historical fiction novel The Water-Witch, or, The Skimmer of the Seas (first published in New York in 1830[24]), Hell Gate serves as the scene for an exciting pursuit of the brigantine Water Witch by HMS Coquette.[25][26] The Water Witch is captained by Thomas Tiller, an adventurous sailor with a romantic flair, and HMS Coquette by Captain Cornelius van Cuyler Ludlow, a principled young officer in the Royal Navy and a native of New York.