First developed in the early 80s, the Twinstack was the first double stack car to become popular with a number railroads. The five unit articulation concept was used to reduce weight and coupler slack. Why five units? Santa Fe had used 10 unit spine cars since the seventies but since one bad section bad-ordered the whole set, 10 units meant the car was out of service too much. Five units provided the perfect ratio of cost savings to down time. The bottom position of each well will accommodate one 40' container or two 20' containers. Some railroads ordered their cars to handle 20 footers only on the two end wells while other railroads opted for 20 footers on the only the middle three wells. The difference lies in whether "hard points" were attached in the middle of the well to support the ends of the 20' containers. The upper position will hold 40', 45', or 48' containers. Twinstacks belonging to SeaLand had extra attachment points so that company's proprietary 35' containers could be carried in either position. The large bulkheads at the ends of each well were designed to hold the top container in place. Even these large structures were sometimes not enough in high winds as empty containers were known to blow off. To stop this rash of un-piloted flying cargo boxes, some cars were equipped with 8' high walls that were welded to the tops of the bulkhead. Hoping this would deflect the problem with the wind, the empty car now stood more than 20' tall! Before the success or failure of this technique could be judged, it became a moot point when someone realized that the InterBox Connectors (IBC's) that locked containers together on ships could be used on trains too. Seemingly overnight, the bulkheads became nothing more than decoration. Gunderson's subsequent double stack designs had no bulkheads. Ironically, the Twinstacks are so rigid that only a couple of wrecked cars have been retired with the rest of the fleet intact and in operation to this day.

FEATURES

? Etched stainless steel platforms and grab irons.
? Knuckle coupler equipped
? Model is semi-permanently coupled together.

Reserve Before February 25,2011

Delivery Expected June 2011