The Rapido Trains HO Scale ACF Helium Gas Tank Car is based on cars delivered between February 1955 and September 1961. The use of blimps by the US Navy and Air Corps began prominently during World War I. At that time, these airships were filled with hydrogen, a flammable gas that was easily extractable. This ultimately led to the adoption of helium, which was sourced from gas fields in Texas, Oklahoma, and Southern Kansas. Helium tank cars could be seen across the country, including states like California, Massachusetts, Florida, and New Jersey. American Car & Foundry produced the fourth, fifth, and seventh generations of helium cars, building a total of 120 cars between February 1955 and September 1961. Each of these 100-ton cars contained 30 individual high-pressure tanks, which could be filled and emptied from the end cabinets. Remarkably, a single car could fill more than two L Class blimps. During the space race, NASA regularly utilized these cars with many remaining in service for the duration of the shuttle program through 2011. In fact, there are photos showing these cars being towed around NASA{s Cape Canaveral site, both on their property and coming off interchange with the Florida East Coast. Due to their robust construction and specialized purpose, these cars had an exceptionally long service life. By 1998, all cars had either been retired from rail service or scrapped, with only a few being preserved today.
 
The Helium Gas Tank Cars are accurately scaled from prototype blueprints and feature fully detailed underframes including bolsters, piping and equipment and appropriate trucks. The cars are accurately decorated and are available individually and in multiple-car packs with multiple roadnumbers. The cars come equipped with Rapido semi-scale metal knuckle couplers. The ACF Helium Gas Tank Car is part of the line of Rapido Trains HO Scale freight cars.