These two cars were designed to transport rock and gravel. A gondola car rocks freely, unloading gravel along the road where it is most needed for construction. The correct term for the crushed stone used by a railroad is "ballast." When laid in the road bed, ballast provides good drainage around the rails and wooden ties.
The Side-Dump Ballast car carries gravel, sand, and stone for repair and construction work along the railroad route. Along with Harbor Department locomotives #31 and #32, these Ballast Cars were donated by the Los Angeles Harbor Department, and helped in the construction and maintenance of the Los Angeles Harbor. Whether these cars worked on the construction of the harbor, moving ballast to build the breakwater, or worked on Catalina Island's rock quarry is uncertain, but they nonetheless gave their all for the City of Los Angeles and now spend their retirement still in the service of the people of Los Angeles here at Travel Town.