I see alot of intermodal action here in Syracuse, NY. I would like to understand the basic idea of having these TTX and other carriers have 5 car lash ups. What is the purpose of having five cars connected like this, is it cheaper or safer this way?
Matt[8]
I assume you are talking about the five pack double stack well cars. There are two advantages in combining freight cars this way. Because containers are relatively light, it is possible to use a single truck to support adjacent cars. However, if a failure occurs, all five cars go out of service. Five is seen as a good compromise for getting the cost advantages of articulation (saving the cost of four trucks) and only losing five cars if a part breaks and the car is Bad-ordered. There is another advantage which is less obvious, based on the way the Westinghouse brake works. The brake application is signalled to the cars by a reduction in pressure in the brake line (this can be from the driver’s automatic brake valve or a broken brake hose). Then a triple valve detects this change and applies the brake. Although the signal moves down the line at the speed of sound, on long trains, the brakes apply from the front. Five pack cars can have a single triple valve and this reduces the amount of piping and speeds the application of the brakes down the train. As well, of course, there are fewer couplers and the slack in the train is reduced. This can reduce the chance of damage to freight.
M636C
I do have another question to go along with the inital question. In what way or mannor are these “five” cars connected? I don’t think I’ve ever seen or noticed these particular double stack cars connected. Are these cars hooked up in a speacial mannor or something? Oh and for my final question, what is a well car? I’ve never heard of that one.
Sarah, this is a 3 unit one by Gunderson
http://www.gbrx.com/Technical%20Bulletins/Maxi%20IV%20car.pdf
And a 5 unit:
http://www.gbrx.com/Technical%20Bulletins/Maxi%20I%20car.pdf
The articulated coupling doesn’t show well, but they couple over the center of the truck between the units.
This pic sort of shows it. One platform rides on the other which rides on the truck.
I see now. I figured those five cars would be more cost efficent and safer. I think in time a person will only see those five car lash ups, instead of just one well car. I think those five car lash ups will grow to maybe ten cars?
Matt[8]
There is yet a third reason - the rolling resistance of 24 axles of a 5-pack is less than the rolling resistance of 40 axles for 5 individual well cars - so the trains pull easier for the same loading.
dd
The trend has actually gone in the opposite direction. Three well articulateds seem now to be prefered over the 5 packs, although that’s probably also due to the newer 53’ well length of the 3 packs, while the 40’ wells usually come in the 5 pack.
The problem with articulated cars in general is that if you have a bad wheel or such, you have to take the whole 5 platforms out of service. Therefore, the fewer wells a car has when and if it is taken out of service, the fewer platforms are also taken out.
Other articulated experiments - The Johnstown American “heavy haul” two platform spine car (very few orders for this one), the Trinity 7 platform roll-on/roll-off flatcar (no orders that I know of), the AutoMax two unit car hauler, the Trinity 2 unti articulated auto hauler (out of production), and the Trough Train articulated coal car. Guess we should add the CP’s “Expressway” and CN’s “Iron Highway” concepts. Not articulated but connected by permanent drawbar - The TTUX “Four Runner” which were just four single axle TTOX spine cars, and the (I forget the TTX classification) 2 x 85 flats for hauling 3 53’ trailers.
I doubt you’ll ever see more than 5 units articulated together for mainstream cars, just too much hassle if one wheel goes bad.
One other problem is that if you’re loading a car for interchange to another RR, you need 10 containers to fill up a 5 pack. All 10 boxes have to be headed to the same place. W/ a 3 pack car, you only need 6 boxes headed the same way.
NS and BNSF see this as an issue with traffic interlining via steel wheel at Chicago
Another big advantage of the articulated cars is the reduction of slack action. You only have 1 coupler worth of slack for for each set of cars vs every car.
So there is pro and cons on this issue. Where I railfan, here in Syracuse, NY. I see alot of intermodal traffic. I noticed that most are the five car lash ups. I see a few well cars, but not much. What I witness, is must of the intermodal trains are half empty. They “fly” by with little or no problem. I think in time these trains will become longer and longer.
Matt[8]
Actually, a five-platform articulated car has two triple-valves, not one. It’s possible to have a failure and cut one of the two out and keep moving. If you have to cut both out, the car must be set out for repair.
Don’t forget, containers can go on the roads when loaded on to chassis and pulled by a semi tractor, so the difference between TOFC (trailer-on-flat-car) and COFC (container-on-flat-car) operations is less than you’d think. They are sometimes restricted due to clearance issues (deep well double-stack cars can still be taller than TOFC, so you’ll see more of them in certain areas).
When the train is going to/from a shipyard with a lot of container ships, like from New Jersey or Long Beach, double-stack 5-platform well cars are the norm.