Deep Logging Winch

The Deep Logging Winch (DLW) is a marine winch that has been modified for polar field use. The winch is capable of logging boreholes 4000 meters deep and can operate at temperatures as low as -45°C. The winch allows full-range speed control down to a complete stop, and can maintain a uniform speed from 1cm/s to 60cm/s. The winch includes a digital depth measuring system with a precision of 1 cm or better, and a cable-tension measuring system. The winch allows for automatic re-spooling of the cable via a level-wind system. The cable is a standard four-conductor logging cable headed with a standard 1-inch outer-diameter Gearhart-Owen variant. The winch has a broadband slip-ring connector enabling it to transmit both analog and high speed digital signals from DC to ~10 MHz.

The DLW was first deployed to WAIS Divide during the 2016-2017 Antarctic season for logging of the WDC06A borehole and later to Minna Bluff in support of RAID during the 2017-2018 field season. Repairs and upgrades for the DLW were implemented, including the addition of LabVIEW program instructions, adjustment of the tension reading (calibration, noise, and oscillation), addition of a cable grip, troubleshooting of a knocking sound witnessed in the field, creation of a reference guide for operation of the LCI-90i display (tension settings, depth zeroing, field calibration), and determination of a method to record tension from the LCI-90i. The winch, however, experienced communication issues as a result of electromagnetic interference (EMI). IDP engineers investigated the issue, and as of spring 2024, the EMI issues are now resolved.

A casing-mounted logging tower is available for use with the Deep Logging Winch.