curtis technology

Curtis Technology is at the heart of major sonar systems used by Navies throughout the world.


Extracts from "The Naval Institute Guide to World Naval Weapons Systems"



Type 2031

Type 2031 is the British towed-array sonar for surface ships. Unlike the U.S. Navy, the Royal Navy uses its towed-array frigates not only tactically but also for surveillance; the RN, therefore, requires greater ranges, achieved by a combination of lower frequency (presumably longer arrays) and more processing. There are two versions: 2031(I) for four frigates operates at low speed and has relatively simple processing; 2031Z, for Type-22 frigates (Batches 2 and 3) operates at a higher tow speed. All combine broad- and narrow-band processing.

Reportedly 2031 is a five-octave system. Type 2031Z incorporates the newer (ca. 1983) Curtis processing architecture, which drastically cuts computer requirements. The Curtis processor is a very fast special-purpose digital computer with a fixed program and over 100Mbytes of memory. In 1987 it was reported that 2031 is normally trailed more than 1600m astern, at speeds of 8-10kts down to 2-3kts; reported range is "over 100nm" which presumably means at least three convergence zones (105nm, in the Norwegian Sea).

The initial R&D contract was awarded to GEC Avionics in 1971/2. Followed by trials on board HMS Matapan and Lowestoft in 1978/81. Four 2031(I) being installed on board modified Leanders in 1982. A fifth was built as a spare. Thirteen 2031Z were purchased.

The associated processor was the GEC Avionics JASOND (1976), the first British digital 360-degree towed-array processor. It was first tested on board a British submarine. JASOND was based on the earlier Sonalyzer (1974), used as a four-channel sonobouy mission replay unit.

Type 2031Z reportedly embodies a new (Curtis-architecture) processor, developed by AUWE, which drastically reduces weight (by 60 percent) and power requirement (by 80 percent) and is also much less expensive than its predecessors. The equivalent submarine sonar is Type 2046.



Norman Friedman




Naval Institute Press







Type 2046

This core processor/display for submarines' towed arrays embodies Curtis architecture. See Type 2031Z and Ferranti FMS 12. This designation has also been applied to the submarines' towed arrays themselves, the replacements for Type 2024s. As of 1987 a total of 27 had been ordered, the first having been delivered that year.









Ferranti FMS 12

This two-octave narrow-band passive-sonar processor was chosen as part of the Triton (Type 2051) program (Oberon-class update) in 1985, to work with flank and towed arrays. The digital signal processor embodies the new Curtis architecture (see Type 2031). The reported frequency range is 10-384Hz and 384-768Hz. The system operates on 32 preformed beams. There is a simple multiple-beam (waterfall) display for surveillance, and a high-resolution vernier (frequency) display for classification. Self-noise can be processed out. Optional improvements are automatic target detection and classification, automatic communication with a submarine's tactical system, hard copy output, and a color display.

The FMS series was announced at RNEE 1983, and trials of FMS 12 were conducted in 1984.

FMS is the basis of Type 2046.

FMS means Ferranti Modular Sonar




Sadly, Ferranti have ceased to exist.

However, we are informed by an ex-employee, that their old site at Cheadle Heath is put to good use. It is used by Stockport Borough Council to park their Dustcarts at night































   Back to Home Page

Copyright Curtis Technology. All rights reserved
Last Modified: 25th October 2001