Harold Frost

 was siphoned off directly from the United States Army Research Corps in early 2075. Frost welcomed the private sector job, with little oversight and reporting required as long as he showed results. The project made headway at first and Frost was confident he could deliver a prototype within months.

However, the optimism was unfounded. As the Excavator was intended for mining, not combat, durability issues manifested quickly. The extra punishment the arm units took when boring into bedrock caused micro-stress fractures and sheared gear assemblies. By September 2075, the research team settled on using black titanium, native to Appalachia. The material had the necessary tensile strength to keep the arm components from tearing themselves apart. Although too expensive for the T-45 power armor due to the expense of the mining process, it was considered an acceptable choice for a corporate design. Although using titanium solved the durability issues, the suit's extra weight made a more efficient reactor necessary. Although the team continued to experiment with new solutions as late as May 2076, they were already way past specifications on the repurposed T-45 reactor, causing overheating and stability issues. After two months of fruitless experiments, Frost's team had to go for broke.

The solution was to go with an ultracite reactor. Although it took trial and error - including slagged reactors and a near-meltdown - Garrahan Mining Co. believed it necessary, as it had the power output and radiation signature necessary for the project. In exchange, they had to make a decade-long commitment to AMS technology. It wasn't the kind of gift the company wanted to receive on Christmas 2076. However, the choice proved prudent, as it allowed the team to complete the project in February 2077, three months ahead of schedule, hastened by AMS' reveal of Watoga and Hornwright Mining Co. launching the Auto-Miner industrial robot line. The crunch time was almost unbearable, with the research team lead going by on coffee, cigarettes, and stale donuts.

By April 3, three complete Excavator units were operational and proved to be a terrific tool. Not only did they have a spotless maintenance record, with nary a single breakdown over two months of constant use, they were already breaking records for the amounts of ore extracted in a single day. Vivian Garrahan decided to play va banque, challenging Hornwright Mining to a duel where the Excavators and Auto-Miners would compete to mine the most ore in a pre-set amount of time. The challenge was a calculated risk, aiming to raise the profile of the company and the project, while securing lucrative contracts in the increasingly automation-obsessed Appalachia.

It was the decisive battle of the Hornwright/Garrahan war: 24 hours of non-stop mining. The challenge started on October 18 and lasted the whole day, with Auto-Miners and Excavators effortlessly chewing through the rock at their designated sites. They were a match for one another and by the end of the day, Hornwright won by a thin margin, just 1.85 tons - less than a single truckload - and stood supreme. Hornwright Mining seized on this tenuous victory as an example of machine's superiority to man.

Appearances
is only mentiond in Fallout 76.