Design and Function
The vehicle was capable of burrowing underground for 10 minutes and up to speeds of 24 kilometers in solid rock at hyperfast mode such as in granite. The drill essentially propelled itself by using the drilled rock to produce a lava-hot ejecta, which was spewed out the back of the vehicle as it moved.
The cockpit and drilling pipes were covered with water, which cooled the drill sledge using a refrigeration device. It was also mandatory for any passengers to wear a cool suit or they would be cremated in the vehicle. The cool suit allowed the passenger to easily adapt to the constantly changing temperatures, which differed based on the speed of the drill sledge. The drill sledge was meant to change warfare by adding in a third battleground, which was the underground.
Mazer Rackham later quickly taught Wit O'Toole and Calinga to drive the drill sledges, so they could drill underneath the Formic landers. They were able to successfully destroy one of the three Formic landers using the drill sledges, but when the Chinese tried repeating the tactic they failed because the Formics had shielded the underside of the remaining two landers.