Architecture Puzzler #548

While waiting for the owner at the last job site meeting, the general contractor mentioned he was trying to decide between a clear-view and a free-lift mast option on a piece of equipment he was considering purchasing. The amount of side shift and the carriage width were also considerations. What type of equipment was he considering?

If we mentioned the names Walter Gropius, Hannes Meyer, and Ludwig Mies van der Rohe in the same sentence, we would probably be talking about what?