DPU on Long Intermodal

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Bruette

Well-Known Member
Intermodal is great, but piggybacks are one of my favorites!

Great Video Ken, thanks for sharing.
 
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Bruette

Well-Known Member
I almost forgot to ask, did you count the cars? I tried, but I lost count. I'm easily distracted by cool equipment.
 

D&J RailRoad

Professor of HO
I'm really not sure how to count the intermodals. Each set of wells or spines counts as one car despite being 1, 3 or 5 platforms. Then each well can carry up to four containers and each spine can carry 2 vans or containers.
 
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dave1905

Active Member
Counting cars depends on the railroad. Some railroads count each car number, regardless of platforms. If you have 20 five packs, then you have 20 cars. Some railroads count platforms, if you have 20 five packs you have 100 cars/platforms. Generally the railroads that count cars don't track which containers are on which car and the railroads that count platforms track which container is on which platform (but not position on that platform.)

The max number of containers you can have on a well is three, two 20 ft on the bottom and a 40-53 ft on top. You can't put four 20's on a well, the lockdowns aren't arranged to support that.
 

santafewillie

Well-Known Member
You can't put four 20's on a well, the lockdowns aren't arranged to support that.
While it is rare, I have seen four 20' containers on wells coming out of Alliance Yard in Haslet TX. I believe that it is a weight situation rather than a lockdown issue. If there are four, they would be empty. Trailer capacity in North America is generally (but not always) about 40,000± per trailer or container, regardless of length. That dictates how much a railcar can hold.
I may not be correct and will yield to Dave as I know that he is closer to the industry than I am. I never saw a double stack on a spine car when they were still in service.
EDIT: Here's a picture that I got from the Internet.
1591037547659.png
 
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GeeTee

Active Member
While it is rare, I have seen four 20' containers on wells coming out of Alliance Yard in Haslet TX. I believe that it is a weight situation rather than a lockdown issue. If there are four, they would be empty. Trailer capacity in North America is generally (but not always) about 40,000± per trailer or container, regardless of length. That dictates how much a railcar can hold.
I may not be correct and will yield to Dave as I know that he is closer to the industry than I am. I never saw a double stack on a spine car when they were still in service.
Typical max Gross Weight(tractor , trailer , payload ) for non oversize is around 80 - 90,000 lbs for a tractor trailer on a public highway or about 5000 lbs to the tire (Texas weight limit 18.5k per axle) . Payload weight is closer to 60,000 , Containers may be less . 40,000 may be a single axle .

To be more precise https://www.txdmv.gov/motor-carrier...-size-weight-limits/37-motor-carriers/permits
It doesn't vary that much state to state because federal law limits 20K /axle 80K gross on the interstate.
 

RCH

Been Nothin' Since Frisco
Re: counting intermodal cars

I see two ways multi-unit cars are counted on the operations side of the railroad.

First, each individual road number is considered a separate car as far as the train list is concerned and as far as hazmat rules are concerned. So, if you have a certain type of load that can be no closer than the sixth car to the head end and your train is composed of five unit well or spine cars, the load must be on the sixth car or farther back, meaning there will be at least 25 wells or platforms between it and the locomotive consist. If your train consists of 32 well cars of various types - singles, three-packs and five packs - then there will be 32 entries on the train list.

The other way has to do with calculating how the train is handled. Trains 100 tons per operative brake and greater have certain speed restrictions placed on them compared to trains under 100 TOB. Tons per operative brake is pretty easy to count if you have all standard single cars, say a unit grain train. Each covered hopper has a single brake valve on it and each one weighs about 130-140 tons gross. So a 110 car train of loaded grain might weigh 14,300 tons. Since there are 110 cars/operative brakes, the tonnage divided by the number of operative brakes comes out to 130 TOB. This train would be restricted.

So here's where it gets tricky. Modern well cars come in odd number sections. The reason for this is that for each three-pack car the end units are equipped with a brake control valve and brake system. The middle unit is essentially a long platform or well shaped drawbar connecting the two cars. A three-pack car is considered two separate cars when it comes to counting tons per operative brake. Similarly a five unit car has three fully functional brake control valves: one on each end and one on the center unit. If you imagine the second and fourth wells or platforms being drawbars instead of wells or platforms, it's like there are three separate cars. So a five-pack car is counted as three separate cars when it comes to counting tons per operative brake.

If you have an intermodal train consisting of 12 five-packs, 8 three-packs and 6 singles your train would have (12 x 3) + (8 x 2) + 6 operative brakes, or 58 operative brakes. Your train would actually have only 26 cars (12 + 8 + 6), so for train list and hazmat purposes the number of cars is 26. Divide the trailing tonnage of the train by 58 and you'll get the tons per operative brake. It's usually under 100 TOB for intermodal trains. When we get a switch list or track list on intermodal or other multi-unit cars each car will have its own sequence line on the train list but in the total number of cars listed the number of operative brakes will be counted.

When you're on the loading and unloading side at the intermodal facility, they may refer to the number of wells or platforms as the number of cars internally. However, when dealing with the crews they tell us the number of cars in terms of the number of entries on the train list. In the example above they would tell me my train consists of 26 cars.

As far as loading four 20-foot containers in a single well is concerned, it may be limited to certain cars equipped for that purpose. The inter-box connectors (IBCs) used to attach the top containers to the bottom containers are placed and locked manually by a ground man or pair of ground men who work together with the crane operator. They usually walk alongside the train just ahead of the crane and place the IBCs in the top of the containers already in the bottom of the well. They are the ones who use those narrow little catwalks from the end of the well car to the 40-foot mark on each car. The vast majority of well cars do not have any ladders or platforms for a ground man to use to position and lock IBCs on the center of the car, so those connection points would be unused. And that's fine when a 40-foot or longer container is placed on top since only the end connection points are used.

Briefly some 56' well cars were used for 28' domestic containers operated by BN America, UPS and others. However, this service didn't catch on and the containers were retired soon after. The 56' well cars are still out there, but they are rare.

One final tidbit of info: tank containers must be in the bottom position in well cars. The outlet valve must face the end of the car. They are never to be placed in the top position. Due to the weight of loaded tank containers they are often not covered by another container.
 




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