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Figure 4. Searchlight sonar concept. A sonar transducer is housed in a dome beneath the hull and is mechanically steered to search for targets. BDI, bearing deviation indicator (developed later during WWII).
ship. Sharpening the blades led to quieter ships with more propeller thrust. The late 1930s also saw the NRL developing harbor defense technology, including an anchored acoustic buoy system called “Herald” (Figure 5) that was intercon- nected to provide alerts and track and locate stealth craft that could enter the port facility or area (Klein, 1968).
Figure 5. Naval Research Laboratory’s “Herald” system for port and perimeter security. A line of radio-coupled hydrophones senses the presence of an intruder.
WWII
In the period leading up to WWII, several farsighted scien- tists in the United States became justifiably concerned with the poor state of US preparations for war. Led by Vannevar Bush, a plan was submitted to President Franklin Roosevelt in June 1940 to form a National Defense Research Com-
mittee (NDRC), with subsurface warfare becoming an ac- tion area for accelerated research and development (Lasky, 1977). It was soon recognized that the US Navy’s existing underwater acoustic systems needed to be improved and new systems needed to be developed.
Three universities (Columbia, Harvard, and the University of California, San Diego) were tasked to develop staff and facilities to accomplish results in specific underwater acous- tic areas, far beyond their normal academic scope, as well as the Woods Hole Oceanographic Institution (WHOI) and the Massachusetts Institute of Technology (MIT). The Navy laboratories and many American industrial concerns were heavily involved. The list is too long to contemplate here but includes major organizations shown on the simplified orga- nizational diagram of Figure 6 (Lasky, 1977).
The Columbia University Division of War Research (CUD- WR) was established in 1941, with headquarters in New York, NY, and a sound laboratory at the US Coast Guard Sta- tion on the legendary Revolutionary War site, Fort Trumbull in New London, CT (CUDWR NLL). This laboratory un- dertook many projects, including research and development
Figure 6. World WarII research and development organizational chart. OSRD, Office of Research and Development; NDRC, National Defense Research Committee. From Lasky (1977).
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