Captain Nicholas Hunter Heck (1 September 1882 – 21 December 1953) was a career officer of the United States Coast and Geodetic Survey Corps. A leading geophysicist of his time, Heck made important contributions in the study of seismology and oceanography. He also revolutionized hydrographic surveying by developing the wire-drag surveying technique and introduced radio acoustic ranging into Coast and Geodetic Survey hydrography.
Early life Nicholas Hunter Heck was born on 1 September 1882,NOAA History: Profiles in Time – C&GS Biographies: Nicholas Hunter Heck the son of John Lewis Heck (1843–1927) and the former Mary Frances Hays (1848–1904), in Heckton Mills – a settlement named for his grandfather, Dr. Lewis Heck (1810–1890) – in Dauphin County, Pennsylvania, near what is now Heckton. After primary and secondary education at private schools in Harrisburg, Pennsylvania, Heck attended Lehigh University, from which he graduated with a Bachelor of Arts degree in 1903 despite enduring an attack of typhoid fever. He continued to study at the university for an additional year, receiving a Bachelor of Science in civil engineering in 1904.
Career
Wire-drag surveying After completing college, Heck accepted civilian employment with the United States Coast and Geodetic Survey in 1904. That year, the Coast and Geodetic Survey introduced the wire-drag method of conducting hydrographic surveys, which prior to the advent of sidescan sonar and multibeam sonar late in the 20th century was the only means of searching large areas of water for underwater obstructions or sunken ships or aircraft.NOAA History: Coast & Geodetic Survey Ships: Heck Between 1906 and 1916, Heck was responsible for much of the development of the wire-drag technique, expanding the capability of wire-drag systems from a relatively limited area to sweeps covering channels two to three nautical miles (3.7 to 5.6 km) in width. Wire-drag surveying played a notable role in clearing unsurveyed channels in the waters of Alaska, discovered hundreds of obstructions elsewhere, and proved particularly useful to the United States during its participation in World War I. The wire-drag technique was a major contribution to hydrographic surveying during much of the rest of the 20th century, not falling into disuse until the early 1990s.celebrating200years.noaa.gov NOAA 200th Top Tens: Breakthroughs: Hydrographic Survey Techniques: Wire-Drag Survey Technique, 2007
World War I The United States entered World War I on the side of the Allies on 6 April 1917. On 22 May 1917, the United States Coast and Geodetic Survey Corps – the ancestor of the National Oceanic and Atmospheric Administration Commissioned Officer Corps – was created as a new uniformed service of the United States to enhance the participation of the Coast and Geodetic Survey in the war effort. Heck was commissioned as a lieutenant in the new service, and was among Coast and Geodetic Survey Corps officers transferred on 24 September 1917 under Executive Order 2707 to the United States Naval Reserve Force for wartime duty with the United States Navy.NOAA History: A Nation at War: World War I Military Records of Coast & Geodetic Survey Personnel: Nicholas H. Heck, Lieutenant Commander, U.S.N.R.F.
On 24 September 1917, the day of his assignment to the Navy, Heck was commissioned as a lieutenant in the Naval Reserve Force, and on 9 October 1917 he was assigned to the Naval Experimental Station at New London, Connecticut. His work there, under the Special Board of Anti-Submarine Devices, involved study of a number of complicated topics but centered around the use of underwater acoustics as a means of detecting submarines and developing a trailing wire device for locating submarines at rest on the sea bottom. On 18 September 1918, he was reassigned to U.S. Naval Headquarters in London, England, to put into operational use the equipment developed during his time in New London. Preparations to put the equipment into service were completed on 5 November 1918, but on 7 November he received orders to suspend operations. The war ended on 11 November 1918, and after that the operation of the new antisubmarine equipment ceased entirely.
On 15 December 1918, Heck returned to New London and resumed his duties at the Naval Experimental Station. On 25 February 1919, he received a promotion to lieutenant commander in the Naval Reserve Force. His Navy duty came to an end on 19 March 1919.
Echo sounding and radio acoustic ranging
Early experiments Heck returned to duty as a Coast and Geodetic Survey Corps officer on 20 March 1919, bringing with him the experience in underwater acoustics he gained during his tour with the Navy, as well as contacts with U.S. Navy, Royal Navy, and United States Army Coast Artillery Corps researchers investigating the practical application of acoustics in an ocean environment.hydro-international.com System Without Fixed Points: Development of the Radio-Acoustic Ranging Navigation Technique (Part 1) During the next few years, developments in the application of acoustics to depth sounding and navigation would afford him an opportunity to revolutionize hydrographic surveying techniques.
By the immediate post-World War I period, research into the use of acoustics had resulted in a primitive ability to use sound to measure depths by bouncing it off the sea bottom and measuring the time it took the sound to make the round trip.hydro-international.com The Discovery of Long-Distance Sound Transmission in the Ocean By early 1923, experiments in this area by the United States Department of the Navy, as well as by the French and the British,NOAA History: The Start of the Acoustic Work of the Coast and Geodetic Survey suggested to Heck that the Coast and Geodetic Survey should look into adopting this new technique of echo sounding into its surveying work, using it to make depth soundings in deep water more quickly and cheaply than it could by deploying long lead lines all the way to the bottom from survey ships; a 20,000-foot (6,096-meter) depth could be measured in only about eight seconds with an echo sounder, while the use of a lead line to determine the depth could take an hour.
In addition, lighthouses, buoys, and lightships along the coast of the United States in recent years increasingly had received navigation aids that used underwater bells to generate sounds which approaching ships could detect; by noting the bearing of each sound source, a ship's crew could determine the position of its ship even when poor visibility did not permit the sighting of a light. In 1923, a radio transmitter was added to these systems so that they could broadcast a signal identifying themselves to approaching ships and informing the ships that they would emit an acoustic signal at a certain defined time interval after the radio signal, allowing a ship to determine its direction and distance from the navigation aid. Meanwhile, the U.S. Army Coast Artillery Corps's Subaqueous Sound Ranging Section had conducted post-World War I experiments in shallow water in Vineyard Sound off Massachusetts in which it had detonated explosive charges underwater at the ends of established baselines and measured the amount of time it took for the sound to arrive at hydrophones at the other ends of the baselines in order to establish very accurate measurements of the speed of sound through water.
Realizing the potential of these applications of acoustics to hydrographic surveying and navigation, particularly along the United States West Coast, where fog frequently interfered with attempts to fix ship positions accurately, Colonel Ernest Lester Jones, then Director of the Coast and Geodetic Survey, in consultation with Coast and Geodetic Survey Corps officers, decided to investigate the use of acoustics in both depth finding and navigation. With his acoustics experience in World War I, Heck, who by then was Chief of the Coast and Geodetic Survey's Division of Terrestrial Magnetism, was the obvious choice to lead this effort. By January 1923, the Coast and Geodetic Survey had decided to install a Hayes sonic rangefinder – an early echosounder – aboard the survey ship USC&GS Guide, which the Coast and Geodetic Survey planned to commission into its fleet later that year, and when Heck contacted E. A. Stephenson of the U.S. Army Coastal Artillery Corps to inform him of this plan and to inquire further about the Vineyard Sound experiments, Stephenson suggested that a system of hydrophones detecting the sound of underwater explosions could allow Coast and Geodetic Survey ships to fix their position while conducting surveys.
Heck agreed, but believed that existing navigation aids would not meet the needs of the Coast and Geodetic Survey in terms of the immediacy and accuracy of position fixes. He envisioned improving on previous concepts by creating what became known as the radio acoustic ranging (RAR) method. In Heck's concept, a survey ship's crew would drop an explosive charge off the ship's stern, detonate it, and note the time the sound arrived at the ship using a chronograph. Hydrophones installed at known positions would also detect the sound when it arrived at their locations and then automatically send a radio signal to the ship at the instant they detected the sound, recording that time with the ship's chronograph as well. The essentially instantaneous notification of the ship that the sound had arrived at a given set of hydrophones would allow the ship's crew to calculate the distance of their ship from the hydrophones by calculating the difference between the time the ship heard the explosion and the time the sound of the detonation arrived at the distant hydrophones and then multiplying this time by the speed of sound through water. By making these calculations for hydrophones at at least two different known locations, the ship's crew could use triangulation to fix their ship's position.Anonymous, "Ocean's Depth Measured By Radio Robot," Popular Mechanics, December 1938, pp. 828–830.
Heck oversaw tests at Coast and Geodetic Survey headquarters in Washington, D.C., that demonstrated that shipboard recording of the time of an explosion could be performed accurately enough for his concept to work. He worked with Dr. E. A. Eckhardt, a physicist, and M. Keiser, an electrical engineer, of the National Bureau of Standards to develop a hydrophone system that could automatically send a radio signal when it detected the sound of an underwater explosion. When Guide was commissioned in 1923, Heck had her based at New London, Connecticut, and arranged for her under his direction both to test her new echo sounder's ability to make accurate depth soundings and to conduct radio acoustic ranging experiments in cooperation with the U.S. Army Coast Artillery Corps. Despite many difficulties, testing of both echo sounding and radio acoustic ranging wrapped up successfully in November 1923.
The cruise of the Guide