Kongsberg Simrad MPT 331 DTRDUB Transponder

Available as:
  • Rental
  • Sale (ex rental)

Kongsberg Simrad MPT 331 DTRDUB Transponder – Available for rental, hire and ex-rental purchase from Ashtead Technology.

The medium frequency Kongsberg Simrad SPT 319 transponder has 56 channels for use with the HPR series and the HiPAP systems. This transponder replies with a single or a multipulse response. This reply contains different information to the HPR or HiPAP systems depending on the current application.

The transponder consists of the following main components: Transducer-head, Battery, Electronics, Housing.

The transponders are supplied with different transducer heads. The last digit in the model number identifies the width of the beam pattern. The battery type provided will vary, as some types require very high energy for the transmitting pulse. The electronic circuitry with software is modular and used with all models, while the physical housing length varies with transponder type.

The MPT has a Dual Beam option. This is designed for use in Long Base Line deep water positioning. The array calibration is performed with the use of a doughnut-shaped beam. When the calibration is completed, this beam will be switched off and the transponder will then only operate with the ±15° beam upwards. This saves battery energy, extending the transponder s lifetime. The MPT can be operated in both Super-Short Base Line (SSBL) and Long Base Line (LBL) modes. All required telemetry functionality is built-in.

The transponders are not only compatible for use with the HPR 400 series and HiPAP systems. The MPT transponders can also be used by the HPR 309/310 and even earlier models with the originally 14 channels. The transponder channel is preset from the manufacturer, but can be altered by either adjusting internal switches or by acoustic telemetry from the HPR 400 and HiPAP systems. HPR 309/310 and earlier systems cannot send telemetry for this purpose.

The acoustic telemetry link may be used to: Set the transponder into different modes of operation, transfer data from the transponder, set the transponder receiver sensitivity and transmitter power level. This is used to achieve optimal performance and battery lifetime. Read remaining battery lifetime. Change the pulse length and turnaround delay

The transponder may be secured to a subsea structure using mounting brackets, or fitted with an anchor weight and buoyancy collar for location on the open seabed. The unit is designed for ROV manipulator handling.

The transponder is normally self-contained with power supply using very long life lithium battery. As an option, a transponder may be externally powered. A rechargeable battery with battery charger are available. The rechargeable battery pack may be used as a replacement for the standard transponder battery L10/36.

The housing material (stainless steel) is selected for long mechanical lifetime, especially in environments exposed to corrosion. The units are very robust.


  • Dynamic position reference for surface vessels.
  • Navigation of underwater vehicles and towed bodies
  • Positioning aid for pipeline and underwater structure maintenance and construction
  • Positioning and re-entry of BOP s Riser angle and BOP angle monitoring
  • Telemetry of inclinometers, acoustic release or external sensors
  • Sensor-reading telemetry transponder (depth and temperature)
  • Position-transponder in an LBL array
  • Master-slave transponder in an LBL array
  • Transponder Range-Positioning mode where it positions itself
  • Range measuring transponder

Technical specifications

3xx30 kHz band
x3x3000 metre depth rated
xx1±15° beam width
xxiDuBDual Beam (±15° upwards and horizontal doughnut )
xx9±90° beam width
DTDepth and Temperature sensors
IOne set Inclinometers (X/Y angles)
IISplit unit with two sets of Inclinometers (X/Y angles)
RIncludes Release mechanism
RspSx 110VacResponder, Short tube, small backup battery
Max depth Rating3000 m
Housing MaterialStainless Steel
Flange and transducer head materialStainless Steel
Overall Length1650 mm
Transducer Beam Widths±90°, ±15°
Transducer Beam Widths with doughnut±15°
Source Level (relative to 1 µPa. Ref. 1m)±90°, 4 steps of 3 dB: max 195 dB ±15°, 4 steps of 3 dB: max 206 dB
Sidebeam (Dub): max 192 dB Rx sensitivity, 2 steps: 106/100 dB (Relative to 1µPa)
Frequency BandTx: 24.5 32.5 kHz Rx: 20.0 27.0 kHz
DuB Version WeightIn air: 62 kg In water: 41 kg
Overall Length1731mm
Transducer Beamwidth Dual Beam (DuB)Vertical: ±15° Horizontal: ±15°
Lithium Battery TypeL10/36
Maximum continuous on-time180 days
Quiescent time930 days
No. of replies, low source level6.4 million
No. of replies, maximum source level1.6 million
Depth Rating3000 m
Total Weight in Air77 kg
Total buoyancy in water65 kg
Overall Height950 mm
Width x Depth450 x 450mm
Diagonal diameter640 mm


Housing Dimensions125mm4.9"
Flange Dimensions178mm7
Weight in air60 kg132.2 lbs
Weight in water42 kg92.6 lbs