The Eames vacuum brake only had one pipe which ran end to end.
Vacuum brake hoses were somewhat larger and heavier than air brake hoses.
The vacuum brake's actuating pistons (which look like a short, squat ice cream cone) were mounted in the trucks with linkage to apply the brake in each one.
Hose connections were on the vacuum line for each truck's brake.
Reservoirs and valves with their related piping were not needed in this system.
The underbody of a vacuum braked car was empty-looking, compared to an air brake equipped car.
The car's hand brake was linked to one of the trucks.
Attached is a drawing of an Eames vacuum brake piston, and a builder's photo of a car built with the Eames vacuum brake.
Although it's a passenger car, a freight car would have the same piping arrangement.