Aeronautical & General Instruments (AGI) Ltd AGILOG Speed Log Submarine Header


Electromagnetic Speed Log System

Aeronautical & General Instruments (AGI) Ltd AGILOG 2


AGI is pleased to introduce our second generation AGILOG Electromagnetic (EM) Speed Log System AGILOG 2 following on from the unprecedented success of its predecessor. Developed for use on surface warships and submarines, AGILOG 2 sets the standard for accurate and reliable measurement of ship’s speed through the water, an essential element in navigation and weapons system integration.


AGI’s international reputation stems from over 40 years of experience in the design and manufacture of ship’s log systems for 45 navies worldwide. Covering all classes of vessels – from nuclear and conventional submarines, aircraft carriers and frigates, to fast patrol boats, mine-hunters and fleet support ships.

AGILOG 2 is based on the well-established electromagnetic principle that a voltage is induced in a conductor by a moving magnetic field. By using the sea water as a conductor, an output is generated as the vessel progresses. Electromagnetic speed measurement is passive in operation and therefore particularly suitable for use in submarines and warships. The EM technology provides reliable and robust speed availability when compared to some alternative technologies.

AGI’s products are highly customised items and are based on a modular design. The AGILOG 2 Speed and Distance Transmitter Unit (SDTU) provides a wide range of system interfaces and expansion options. AGILOG 2 provides single or dual axis speed measurement, with multiple RS422 serial outputs and Ethernet interfacing built in.

AGILOG 2 also offers GPS assisted calibration which uses ground speed data to calculate the average true speed over a calibration run. This method does not depend on accurate distance and time measurements and is therefore easier to accomplish.

System Configuration: Typically the AGILOG 2 system comprises of the SDTU, Underwater Sensor(s) (or Probes) and Multi-Function displays.


    • GPS assisted calibration
    • Dual or quad calibration curves
    • Dual axis option for forward and athwart ship speed/distance
    • Ethernet interface
    • Dual sensor option
    • Underwater sensor selection
    • Low magnetic signature sensors (contact AGI for specific data)
    • Simulation more selection
    • Self-test capability (BITE)
    • Trip Meter
    • User friendly interface
    • Sensor replacement without dry docking


Wheelmarked to meet Marine Directive 2014/90/EU

EMC – Mil-Std 461F

Shock – Mil-Std 901 grade A

Vibration – Mil-Std 167-1 and EN60945

Environmental – EN 60945

Power Supply – Mil-Std 1399 & EN 60945


AGILOG 2 datasheet

Electromagnetic Speed Log



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AGI NTD 16pp broch


T: +44 (0) 1202 685661

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