According to Trailer Body Builders, the trailers were an answer to the need for easy storage and deployment of large amounts of power cord. The trailers were also narrowed and made shorter to fit into the mine's elevator for transport into the mine.

Felling said that the FT-6 R was designed for manual hand-pull deployment of the cable, possible by disconnecting its retrieval system and resting the reel bar on SAE 660 bronze bushings. When retrieving the cable, the user needs only re-engage the drive.

While company utility and telecom product manager Mark Rapp did not identify the customer mine, he told the trade website that the 5,980-pound GVWR/4,060-pound capacity (2,703kg GVWR/1,841.5kg capacity) trailer was the ideal solution.

"With hundreds of 6Rs already in service, there was never any doubt they would hold up in such a harsh environment," he said, adding that hydraulics were powered by a Tier IV, liquid-cooled, two-cylinder diesel engine due to emissions regulations.

The machine's KDW 702 Kohler/Lombardini engine helped it to create 2,250 psi/155.1 bar for a continuous hydraulic pressure rate of 10 gallons/37.85L per minute and provide 2,100lbs/952.5kg of line pull.

The reel trailer features safety features including a spring-back-to-centre hydraulic lever valve that can aid in stopping the unit in case of emergency, and a flow control feature allows the reel's revolutions per minute to run at a precise speed. It is also designed with four 12V 2,000-lumen work lights, powered by battery, for total illumination.

Rapp said the reels for the mine's needs were designed to hold 350ft/106.6m of power cable that was 2.5in/6.35cm in diameter and 5lbs per foot/7.44kg/m, and removable from the trailer when not in use so the reels could store securely, on octagonal flanges, on the floor of the mine.