Is there a real benefit of the articulated railcars for containers? It seems like there would be more of them if there was a real benefit. What am I missing?
The bulk of the IM cars I see on the Deshler cam are three and five packs. Deshler is just a few miles from the CSX North West Ohio IM facility at North Baltimore.
Those three and five packs are considered one car. A big savings is the fact that a five pack only has six trucks, versus the ten that five individual cars would have.
There are plenty – lower tare weight, shorter length for the TEU capacity, and better tracking, in addition to some of the others that have been mentioned.
There are plenty of them, and where they are used they’re a real benefit to operations. The ‘catch’ comes if you don’t have enough containers to fill all those wells in a given block, or the origin or destination traffic to load in groups of 6 or 10. A very similar issue was responsible for the effective demise of the original ATSF ‘fuel foiler’ sets, which were essentially 10 skeleton flats articulated across common trucks. Unless you had the ability to piggypack or Letroport all the trailers at either end, you were stuck with a car that couldn’t circus load or unload… and if you didn’t fill all the flats, your quartering drag began to rise distressingly. As I recall the sets were cut down to 5, and of course ultimately replaced with COFC for the kinds of run ATSF was ‘best at’.
The trade-off is in flexibility. A five pack has much less tare weight (and less slack) than five individual wells, but all five wells get taken out of service when the car is shopped for any reason. And there are limitations on how long a car will even fit into the typical car repair facility, especially in colder climates.
Much less draft gear, couplers, knuckles, air hoses, glad hands. Less air leak points. Best of all much reduced slack action. Reduces chance of slack action derailments and product damage inside containers. More wells per foot of train legth.
3 packs and 5 packs are a quantum improvement from the TTOX 2 axle cars that were designed around a single container length - and were a derailment hazard as longs as they existed.
Intermodal facilities when it comes to oredering car supply tend to order by total length of equipment - ie. “I’ll need 8000 feet to meet tomorrow’s expected loading”. That 8000 feet can be made up of single 89 foot intermodal flats, 3 packers and/or 5 packers. The car supply orders are not couched in specific car types.
5 packers have a length of under 300 feet.
One other thing I have noticed is the 5 pack cars only take 40 ft containers. I’ve never seen a 5 pack setup for 53 foot containers.
Not all 3 and 5 packs are articulated. There’s plenty of both kinds that are drawbar connected. Makes it fun trying to calculate operative brakes and axle counts when you don’t have documentation that states whether there articulated or drawbar connected.
Jeff