To build the USGS magnetometer trailer we worked with Ed St. Marie, a retired locomotive mechanic who had a woodworking shop in his garage.
Ed lived in Proctor, Minnesota, a suburb of Duluth.
In the years when Minnesota was the world’s largest miner of iron ore, the ore came from the Missabe district, about a hundred miles from Duluth. The Duluth, Missabe and Iron Range Railroad carried the ore from the mines to Lake Superior ore boats. The railroad had the heaviest trackbed in the world and the ore trains were some of the longest.
The prime mover for these trains was the 2-8-8-4 Mallet steam locomotive, a monster that had two sets of eight drive wheels driven by four steam cylinders.
Ed had been foreman of a team that serviced these leviathans. He had worked in the D. M. & I. R. roundhouse in Proctor, the largest locomotive roundhouse in the world.
Ed took us into the roundhouse one day. He told us that despite the size and weight of the Mallets, his servicing team could move them without help, using wedge bars placed under the wheels.
Three of these historic engines are still on display in Proctor, Duluth, and Two Harbors, Minnesota.
For more information on Mallets, google ‘Union Pacific Big Boy'; also ‘Mallet Locomotive’ in Wikipedia.