Western Railroad Discussion > The Dynastack Articulated Well Car

FreightCar America's DYNASTACK™ 5x40' Articulated Double-stack well car. NOKL 219907, a rare prototype? Built: 6-07

Mr. MRL



Edited 2 time(s). Last edit at 11/30/11 15:55 by MrMRL.

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I haven't seen one of those before.

Ted Curphey
Ontario, OR



Edited 1 time(s). Last edit at 11/30/11 16:08 by funnelfan.

As far as I know it is a one of a kind prototype. I believe it spent the last few years at the Transportation Technology Center in Pueblo CO. Now it looks to have been release into the wild...cool.

Jeff Eggert

blueflag Wrote:
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> As far as I know it is a one of a kind prototype.
> I believe it spent the last few years at the
> Transportation Technology Center in Pueblo CO.
> Now it looks to have been release into the
> wild...cool.
>
> Jeff Eggert


Interesting. I first saw it about a year ago at BNSF's Hobart Yard in Los Angeles, CA but wasn't in a position to photograph it. Nice to see it again, considering it is a unique prototype in a sea of well cars.

Mr. MRL



Edited 1 time(s). Last edit at 11/30/11 20:57 by MrMRL.

Its Freight Car America's design for a 5 pack well car.
http://www.freightcaramerica.com/Dynastack-Drawing.htm
Roger Beckett

So how much lighter is this compared to say a Husky Stack?

Looks like an erector set! Interesting car though!

The rivets had me thinking that they may have used aluminum in the truss part of the car, but the website says it's all steel.

I think they may have missed the boat, as the need for 40' wells is now shrinking and unlikely to grow again. They really need to design a 53' car.

Ted Curphey
Ontario, OR



Edited 1 time(s). Last edit at 11/30/11 20:03 by funnelfan.

This car spent most of the summer roaming the UP between the PNW ports and Chicago. I spotted this car 3-4 times track side doing roll-by's of passing stack trains between La Grande, OR and Nampa, ID

Posted from iPhone

funnelfan Wrote:
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> The rivets had me thinking that they may have used
> aluminum in the truss part of the car, but the
> website says it's all steel.
>
> I think they may have missed the boat, as the need
> for 40' wells is now shrinking and unlikely to
> grow again. They really need to design a 53' car.

Actually the need for 40' wells is pretty strong. 40' cans are the standard for marine traffic.
The current standards right now are 40' for marine traffic and 53' for domestic traffic.

While I am a big fan of the idea of truss designs in railcars to reduce tare weight (especially in regards to boxcars), it's not clear that this car really does much to reduce tare weight for intermodal well cars.

The Dynastack is 266 ft in length (5 wells) with a tare weight of 170,200 lbs. By contrast, a 3-well car with 53ft wells is 204 ft long with a tare of 125,000 lbs.

I can't find length and tare stats right now for cars with 5x40ft wells catering to the international biz.

If there's little weight advantage, why bother? Especially when the truss design is less aerodynamic, and the containers being carried by the cars basically don't need structural support except at their cornerposts.

I agree, I don't see the point of this car. In the early 1990s I did a comparative study of stack car designs for Burlington Northern (I was a consultant at the time). The IBC stack car came out as the best choice, based on the following:

1) With 39-ton axle loads, max gross weight of an intermediate platform was 156,000 lbs.
2) Max weight of two 40-foot containers is 130,000 lbs. (2 x 65,000)
3) Tare weight of the well should be no more than 26,000 lbs.

Your weight for the five-unit car gives an average of 34,000 lbs., but of course the end platforms are heavier, so it looks to weigh about the same as the IBC designs I looked at 20 years ago. Big deal.

Bandito Wrote:
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> The Dynastack is 266 ft in length (5 wells) with a
> tare weight of 170,200 lbs. By contrast, a 3-well
> car with 53ft wells is 204 ft long with a tare of
> 125,000 lbs.

Doing the math a 5 x 53 would weigh ~208,000#, which is 22% more that the DynaStack.

NSTopHat

As I couldn't find the tare for 5x40ft wellcars, I provided the 3x53ft wellcar stats as a proxy to indicate tare per foot. (Positing a 5x53 car isn't really relevant, as there are no such cars, and if there were they'd be far longer and carry more cargo.) The Dynastack is about 640 lbs/ft, and a 3x53 is roughly 612 lbs/ft.

But I found the info on the standard 5x40's and they weigh in at 177,000. So, as surmised, the Dynastack offers little improvement over standard design cars (at least in terms of tare). Only 6,800 lbs, or 1,360 per well.

I would imagine that the side walls of standard wellcars provide essential structural strength for withstanding the train forces, and by trying to take weight out of the sides, the Dynastack had to add back more weight and strength elsewhere to compensate.

Bandito Wrote:
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> Positing a 5x53 car
> isn't really relevant, as there are no such cars,
> and if there were they'd be far longer and carry
> more cargo.

Actually, there are two prototype 5x53s in existence. They weigh 225,000 lbs and are 330 ft long. Updated designs have been issued reducing the weight to 204,000 lbs (with 331 ft. length), or 616 lbs/ft.

> The Dynastack is about 640 lbs/ft,

About a 5% improvement, see below.

> and a 3x53 is roughly 612 lbs/ft.

125,000 lbs, 203.8 feet, makes for 613.3 lbs/ft.

>
> But I found the info on the standard 5x40's and
> they weigh in at 177,000.

I think 179,000 is a better average. 265 feet long. So 675.5 lbs/foot.

> So, as surmised, the
> Dynastack offers little improvement over standard
> design cars (at least in terms of tare).

Yes, a modest improvement.

Marine stack train market is not growing like domestic stack train market. It might even start to decline.

Best regards,

Rob L.

Aside from trying to develop 5x53 cars, one thing that could be done to improve utilization per train-foot would be to reduce the use of single-well 53' cars. I seem to see a fair number of them mixed in with the 3x53's (just impressions--no data), and that can really cut into the number of containers per foot--at whenever train length is a consideration.

I would think that 5x53's would work best in the highest volume point pairs. The shorter cars can offer more flexibility in load planning, allowing for higher car utilization, especially when dealing with a higher number of smaller volume destinations.

On the international (IPI) side--especially at an ondock terminal--having those 3x40's and 4x40's can make it much easier to keep the slot utilization high while loading a variety of destinations.

The same potentially applies to 53's. What if you've got 5 more boxes and all you have is a 5-well car? Blow 5 slots, or leave the 5 boxes and the car behind for the next train? With a 3-well car it's much easier to decide to load them up with only a single blown slot.