Shipping container weight

[MLG4812]

Hello,

I am currently working on a point to point land bridge layout involving stack trains. It's totally unprototypical as I am using motive power circa mid 70's to 1980. Modern stacktrains did not exist then of course. Also, the route covers mountainous territory with a ruling grade of 1.6%. The decision to use 4 or 6 axle power leads to this question..What is the average payload weight of a 40' hi-cube container using today's standards? I can't find anything. Most information I have found is TEU weight (twenty foot equivalent) in average tons. Many websites say to double the TEU weight for a 40' equivalent. I don't personally trust this method. Also, I realize that container cargo weight will vary greatly per shipment. A container of teddy bears from Singapore will naturally weigh less than a container of frozen herring from Nova Scotia. I am just looking for an average. If loaded containers are heavy, I will use 6 axle on my layout. I'm leaning that way anyway. I want to use my 2nd generation SD40-2's.

 

   

[Anonymous]

Maximum weight of a container is governed by the fact that generally you have to truck it between the ramp and the customer's dock, and in most U.S. jurisdictions that sets the container gross at 40,000 lbs.

Average weight is not so easy to determine.  Many things that go in containers such as auto parts, clothing, electronic goods, toys, packaged food, etc., are low density.  Backhaul container loads such as scrap paper are high density. 

However, you're asking a "what if," namely, what would stack trains have looked like had containerization and the double-stack car been invented about 10 years earlier?  In that era most U.S. railroads preferred four-axle for merchandise business because it was a more cost-effective option -- the real need for six-axle didn't appear until single-unit horsepower climbed into the 4,000-hp range, after which it became difficult to get that horsepower onto the rail consistently.  A 3,000-hp, six-axle unit is simply dragging around extra weight once speed increases to 25 mph or so. 

I think you could go either way -- GP40s or SD40s -- and justify it.  You could even mix them up indiscriminately on your stack trains.  Heck, Rio Grande did!

S. Hadid

[MLG4812]

Thanks 1435mm, I'm trying to get as "unprototypically" close to prototype as possible.

 

 

[twcenterprises]

Well, to properly answer your question, an EMPTY 20' container weighs about 4000 pounds, and a 40' container is about 8000 pounds.  I'll leave it as an exercise for you to convert to metric.  The loaded weight can vary greatly, but there IS NO weight restriction in the US as far as the container weight itself goes.  The containers themselves are usually marked in pounds and metric as to what their max load is, usually in the range of 60-70,000 pounds (including the weight of the container itself).  The only rule in the US governing the max load is the 80,000 pound rule, which is the maximum allowed (without a permit) for tractor, trailer, load, chassis, etc., combined.  Given that a typical US road tractor can weight between 16,000-20,000 pounds, a container chassis will be about 8,000, and a 40' box another 8,000, then a 16,000 pound trailer (container/chassis combo) will bring the empty weight to 32,000 pounds.  You could legally load 48,000 pounds of cargo without a permit.  With that, the loaded container would weigh 56,000 pounds.  A typical US 53' road trailer weighs about 15,000 pounds empty, BTW.  Many states have special rules and exemptions for international shipments, for example, in Georgia, where I live, they allow containers extra gross weight without permits, has something to do with Free Trade Agreement, or something like that.

So, in my educated opinion, I'd guess an "average" container weight would be 40-50,000 pounds.  That would be my basis for calculating tonnage ratings.

Professional trucker by trade.

Brad

[twcenterprises]

One other thing.  You're using motive power from '70's and 80's, since stack trains became common after the early 80's, power from the 70's would still be around to haul it.  NS used SD40-2's to haul intermodal trains until very recently, and even today if needed.  I primarily model 1957, but also (on occasion) model 1985, using SD40-2's, aging (for the era) GP30's, and the like.  I use them to haul double stacks, auto racks, and high cube boxcars (but with a caboose, they were still around until the early 90's).  I have most of this still in Southern Railway paint, but some in NS.  Fairly accurate for the are, but lacking N&W equipment (claiming it's all still in VA.)

Brad

[ndbprr]

In addition to the truck weight restrictions you also need to take into account the FRA axle loading restrictions which is 80,000# per axle.  That means a free standing car with four axles can handle 320,000#.  But since they are often five unit cars with one truck between two cars this cuts the effective axles to two per car except the end cars which have three so the intermediate cars would be limited to 160,000# and the end cars would be limited to 240,000#.  All of which is probably not even a consideration because the truck weights are the prohibitve factor UNLESS the cars are offloaded at a location where they are not trucked (but I don't know of anything like that).

[MLG4812]

Wow, thanks guys. I haven't checked this post in a while. I thought it had stopped receiving replies. Good point about the trucking tonnage limit. Good economics would be to cram as much into the box as possible. I don't know how many containers are less than truckload when they come off the boat but I would guess that they are pretty full. Would you agree that most containers will box out before they reach their tonnage limit (the whole teddybear thing in my original post). One thing I also thought about...six axle was more or less the "new big thing" in that era as opposed to the staple it is now. Like you said, railroads used them on everything from coal drags to intermodal in the flatlands. Nevermind economics or fuel savings. A geep would work just fine in many of those operations. My conclusion: I guess I really could go either way and still be correct. But that's the beauty of model railroading, isn't it? I could head my stacktrains with a lash-up of RS-1's and still be in the clear.

 

[HEdward]

I worked for CTI back in the 80s.  They owned nearly a half million containers which they leased to all the major shipping comapnies.  As container shipping became the standard, the shippers bought their own units and built their own handling facilities.  Deep well cars were rare but I did see units stacked rolling past the minor league ballpark in Oneonta NY.(before I-88 was built)