Piggyback Ramps like those in this easy-to-build Walthers Cornerstone HO Scale kit are used across the continent for loading and unloading trailers and other vehicles from flatcars. From the 1950s into the 1980s piggyback trailers were driven onto flatcars at yards and terminals. While this "circus-style" loading has since fallen out of favor for trailer loading, many loading ramps are still in place for special loads. They are also found at team tracks where cargo was lifted with a gantry crane. The Piggyback Ramps kit includes four ramps including a wood platform-ramp combination, a small clerk's office, overhead crane and a power pole.