Hell Gate blast

New York history

Written by

The Information Architects of Encyclopaedia Britannica

Last updated

June 29, 2026

Quick Summary

The Hell Gate blast in New York Harbor in 1885 was a notable use of Sprengel explosives. This event involved the removal of "Flood Rock," which was a hazard to navigation. The explosion utilized a combination of 34,000 kilograms (75,000 pounds) of dynamite and 110,000 kilograms (240,000 pounds) of potassium chlorate mixed with nitrobenzene. The ingredients were prepared just before use, with cloth bags of chlorate soaked in nitrobenzene and loaded directly into boreholes. This event was a significant application of this type of explosive in the United States.1

Summary created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

2 Britannica Sources

Ask Britannica AI about this topic

Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.

explosive
Sprengel explosives
…small except for the spectacular Hell Gate blast in New York harbour in 1885, in which a combination of 34,000 kilograms (75,000 pounds) of No. 1 dynamite and 110,000 kilograms (240,000 pounds) of potassium chlorate–nitrobenzene were used to remove “Flood Rock,” a menace to navigation. Cloth bags of the chlorate…
Read More
…small except for the spectacular Hell Gate blast in New York harbour in 1885, in which a combination of 34,000 kilograms (75,000 pounds) of No. 1 dynamite and 110,000 kilograms (240,000 pounds) of potassium chlorate–nitrobenzene were used to remove “Flood Rock,” a menace to navigation. Cloth bags of the chlorate…
Read More