The Operating Twin Dump Coal Car No. 3359 was designed as a replacement for the No. 3469 and was available from 1955 until 1958.

This car came with a No. 90 Controller and two OCT Lockons that would allow it to dump coal at any location. It also came with the long Unloading Bin No. 160 Variation E that was designed specifically for use with this car. This operating car could be used with the No. 97 Coal Elevator, No. 397 Coal Loader, and No. 497 Coaling Station.

Unlike its predecessors, this dump car is made almost entirely out of plastic. Produced on a GRAY plastic body with RED plastic under frame that covered the bin raising mechanism, the "LIONEL LINES" lettering and car reporting data was heat-stamped on. Early editions had bar-end trucks with magnetic couplers, while later editions would have tabbed couplers. Note that the number "335955," is printed on the side. The suffix "55" indicates the first year of production.

The bins were dumped one at a time by a series of stepped sequences that used a cam to gradually raise each bin. There are no variations.