The IRBM Missile Car No. 6823 would carry two IRBM (Intermediate Range Ballistic Missile) missiles in various positions depending on the type of flatcar mold that was used. This would determine the position of the racks that hold the missiles and is the only variation for this car. The (A) Variation uses mold No. 6424-11 Die 3, and the (B) uses mold No. 6511-2. Neither of these variations effect the value of this flat car. This car was produced in 1959 and 1960, and came with AAR trucks and disc couplers.