curtis technology

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


Extracts from " Jane's Underwater Warfare Systems"





FMS Series Sonar Systems


Family of passive and active sonar systems


The Ferranti Modular Sonar (FMS) series is an integrated range of low cost, compact, high performance systems, developed by the company as a private venture to meet the needs of a wide variety of platforms and operational roles, and is based on the new generation of sonar designs selected by the Royal Navy. The series has been designed to optimise performance, simplify installation and in-service support, and reduce through-life costs.

The systems within the series consist of:

FMS12 - passive narrow-band (2 octave)

FMS12 - passive narrow-band (5 octave)

FMS20 - active (4ft hull array with VDS option)

FMS21 - active (6ft hull array with VDS option)

FMS30 - passive broadband (single shelf - 3ft array)

FMS31 - passive broadband.

All FMS systems employ the latest advanced distribution digital signal and data processing techniques to provide significant cost, space and performance improvements over the majority of current equipments. These techniques are subject to continuing development to further improve these factors.

Signal processing, based on advanced 'Curtis' techniques, is achieved using programmable Ferranti digital signal processing modules which can be easily configured to meet the optimum performance requirements of specific array outfits and for easy through-life enhancement.

The data processing equipment is based on multiple M700 processors, arranged in distributed arrays. The use of large numbers of these interconnected in the data processing system gives very high levels of computer assistance and automatic operation. Features such as automatic detection, tracking and classification of multiple targets are provided. Standard programmable modules for both signal processing and data processing functions enable significant reduction in spares holding, simplify maintenance and reduce overall cost.

The ergonomically designed operator consoles allow single operator control of the complete system. Each contains two 1000 line high resolution raster displays and operator's desk. The man-machine interface includes a trackerball, nudge keys and a touch-sensitive plasma panel. From the plasma panel the operator can select various displays, focus on selected beams, scroll around beams, set verniers, annotate features on the display and select a variety of cursors. The trackerball and nudge keys are used for fast and accurate positioning of the cursor to provide specific displays of frequency, bearing, time and harmonic ratio information.

Each sonar in the FMS series is configured by selecting from a range of standard modules. This allows active or passive sonars for ships and submarines, large or small, to be proposed to suit customer's specific requirements. The modules are the same as, or closely related to, equipment in or ordered for RN service. This capability enabled Ferranti to offer low cost and risk solutions to most sonar requirements.

The processing equipment can be housed in air- or water-cooled equipment practice cabinets to meet customer's individual requirements.



Bernard Blake




Jane's Information Group




0 7106 0884 5



Type 2031Z Sonar


Towed array sonar system


The Type 2031Z is a towed array sonar system currently being fitted to all new ASW frigates of the Royal Navy. Using the innovative 'Curtis' architecture developed at the UK Admiralty Research Establishment in Portland, Dorset, the 2031Z electronic signal processing suite has, because of its compactness, a considerably lower installed cost than other systems, and yet provides a multi-octave broad- and narrow-band analysis facility capable of tracking the most elusive threats.

The array itself is towed behind the ship and has a very low self-noise characteristic and is considerably longer than that used by any other self-contained sonar. It provides good bearing accuracy, even down to the very low frequency end of the acoustic spectrum. The combination of an advanced signal processing architecture and a high performance towed array ensures that the system is a dual capability sensor, able to fulfil both the tactical and surveillance role. A 2031Z equipped frigate can, therefore, act as an ASW picket or as a close escort.

The modular nature of the 2031Z, both as regards the digital signal processing electronics and the towed array itself, makes it possible to configure other types of sonar systems from the same range of modules. As an example, a variant of the 2031Z signal processing, suitable for submarine applications, is also available and has been delivered to the Royal Navy.

The Waverly Division is able to provide, in collaboration with other suppliers, complete towed array sonar systems for export applications.

Operational Status

The Type 2031Z is now in series production for the Royal Navy for installation into its new ASW frigates. Twenty-two systems had been ordered as at May 1989.





Type 2046 Submarine Sonar


Passive hull-mounted sonar.


The Type 2046 sonar is an integrated, passive system designed for the Royal Navy nuclear-powered attack submarines, and is also being fitted into the Type 2400 Upholder class of conventional submarines.

Developed from advanced 'Curtis' digital signal processing technology, and including FMS 12 display processing with Ferranti M700 Argus processors, the Type 2046 provides long-range target detection, classification and tracking information.

The system provides 360 bearing cover, multiple beam resolution and broadband surveillance with a high resolution narrow-band frequency expansion facility. The operator interface consists of a four-screen, two-operator console suite with touch sensitive plasma panels.

Like all the Ferranti sonar systems the Type 2046 is built to a modular design to make maximum use of the latest technology, to save space and cost, and to assist through-life enhancement of the system. It is also equipped with fully integrated built-in test equipment for ease of maintenance.

Operational Status

Twenty-seven systems have been ordered for Royal Navy submarines and 10 had been delivered by the end of 1988.






   Back to Home Page

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