OBERON - RADAR, IFF FITS and Other Systems 


Type 1002 (initial fit) . This was an 'X' band, surface warning set used mainly for blind pilotage. It has two modes of operation. First, it could be operated in either sector scan of an all round sweep. The antenna is mounted on a periscopic mast ( type AKT) hence the radar can operate while the submarine is at periscope depth.

Secondly was periscope ranging. A facility for direct radar ranging existed on the search periscope and operated by 'cut push' on the periscope. The resultant range could be fed directly to the fire control calculator or a CRT display

Type 1006 Kelvin-Hughes navigational radar (final fit). This was a solid state radar, very small and compact.

Introduced: 1974
Peak Power: 25 kW
Frequency: 9.445 GHz (9.65 GHz for submarines)
Wavelength: 3 cm
Pulse Length: 0.8, 0.25 and 0.75 microseconds
PRF: 800 or 1600 pps
Aerial Outfit: AZJ, AZK for aircraft
                    AKU for submarines

Type 955 (Initial fit. Final fit unknown). Only the transponder was installed, no interrogator. This equipment enabled an aircraft or ship to challenge the submarine with an IFF code. If the correct response code was set the submarine would raise its E.C.M. mast and the IFF in the submarine would be switched on. The transponder would automatically send back the correct answer to the challenge from the ship or aircraft.
Attack Periscope - Model CH24

This is a monocular periscope with a magnification of 1.5 (low power) or 6 (high power) . The size of the tube at the top is 2 inches on diameter, thus making the attack periscope difficult to detect either visually or or by radar. Its length is 44 feet , 9 inches which is four feet longer than the search periscope. This enables the submarine to be slightly deeper when attacking , a tactical advantage in case of prying aircraft and enables the submarine to save seconds if forced to go deeper by an escort. It is fitted with the following:

a) Artificial horizon sextant.
b) Action broadcast microphone
c) Split image range finder
d) Range transmission to the fire control calculator .
e) Bearing transmission  to the fire control calculator and the bearing indicator above the chart table.
f) Top window deicing heaters.

Search Periscope

This is a type CK24 binocular periscope. The size of the tube at the top is 7.5 inches in diameter which makes its a good target for visual detection or a good radar target. Its length is 40 feet, 9 inches and is fitted with the following:

a)  Ranging radar  - very short transmission duration
b) Action broadcast microphone
c) Split image range finder
d) Camera aperture.

Electromagnetic Log - This log is designed to detect and display Speed ( 0-40 knots) and distance in tenths of a mile.

Mk 23 Gyro. (Initial) Two were fitted. There were no compasses aboard. The gyro supplied course information to many other devices. It was capable of indicating True North accurately in latitudes of 75 North or South.

Sperry Mk23 gyro. (Photo Courtesy Gyro Systems Co.)
SIRS (Submarine Installed Radiac System Mk 3 NRS). It provided, at a central control position, the ability to detect  the following radiological hazards:

        a) The external air dose rate of gamma radiation.
        b) The presence of gamma emitting radioactive contamination in the sea.

This equipment comprised of an air dose rate detector, a water activity detector, an indicating unit and power supply. The air dose rate detector (Mark 8NH) was mounted in the junction box for the snort head valve heaters in order that it could monitor the air prior to and during snorting. The water activity detector (Mark 9NH) was mounted internally on the pressure hull, clear of other equipment so as to "look through" at the sea water. A display unit (Mark 4NV) was fitted at the central control position and contained meters which indicated the level of radiation in the air and water surrounding the submarine.

Fire Control -   Singer Librascope SFCS Mk 1 Mod C .(Final)

Contributors and Credits:

1) Don Courcy VE2GG <doncourcy(at)aol.com>   Web http://www.radioman.ca
2) The Canadian Submarine Service in Review by J. David Perkins
3) RCN  C.F. 'O' Class Submarine Training Notebook - Chapter 14, Operations Equipment Circa, late 1960's and 70's.
4) Gyro Systems Co.  http://www.gyrosystems.com/milcomp6.html

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Dec 23/08