The Operating Radar Car No. 3540 was available for two years, 1959 and 1960, and was built around a RED flat car mold No. 6511-2 that was modified by holes that were cast into the plastic injection mold for the control panel lamp, the two-dish microwave antenna, and a third for the drive shaft to operate the radar antenna. The car is heat-stamped in WHITE with the number to the left of the "LIONEL" inscription on the sides that is typical of post 1958 manufactured cars that used AAR trucks.
A TAN superstructure was mounted on this car that used tabs at the ends and along the sides. This was why the 6511-2 mold was needed to hold this superstructure. The superstructure has a lighted GREEN radar scope that was read by the operator that has a painted face and hands. There is another control panel on the side that is the same as that which was used for the No. 44 Mobile Missle Launcher. The microwave two-disc YELLOW antenna is similar to what was used on the No. 465 Sound Dispatching Station and the No. 443 Missile Launching Platform. At the other end of the car is a BLACK radar antenna whose grid is painted SILVER, and this antenna rotates as the car moves.
To rotate the antenna on this car it was necessary for Lionel to modify the AAR trucks. On the brake wheel end of the car the truck is equipped with ground pick-up springs on the axles and a center rail roller pick-up. At the other end, the wheels are not "free-rolling" as are most of these trucks, but are pressed on to the axles. This is necessary because the antenna is connected to the axle by an O-ring that moves the antenna. The axle is larger in diameter and is finished to better grip the O-ring. Unfortunately, the O-ring material that Lionel used was incompatible with these axles which is why the originals are often found in melted condition. This means of rotation was also used on the No. 3512 Fire Ladder Company Car and the No. 3545 Operating TV Monitor Car with the same melted O-ring results. These O-rings have been reproduced.