Tofc Cosolidation

[dwil89]

QUOTE: Originally posted by foureasy

How much trouble would it be to get all full hieght stacks together instead of a mish mash low/high consist. Seems the added time required would surely
decrease fuel usage due to wind resistance.Am i wrong?

This is a valid observation. When I'm watching NS Trains on the Pittsburgh line, along with dedicated stack trains with low high mixed, I see trains with stacks,then a section of trailers, then maybe some empties, the you might see a few more stacks, more empties, trailers, stacks....I guess it is just blocks of cars to be set out at different locations..nobody has the time to reclassify the train to get all the "like traffic" together, so you end up with a mishmash....These trains are usually overpowered anyway...3 or 4 engines pulling this time-sensitive stuff, while a heavier freight slogs upgrade on the next track with 2 units, and hopefully a pair of pushers on the rear. Dave Williams http://groups.yahoo.com/group/nsaltoonajohnstown

[M636C]

Dave,

We have very few articulated double stack cars in Australia for the very reason you quote, load limits. We mainly have bar coupled sets of independent well cars. I don't know how often load limits are reached with either type. We sometimes use conventional flat cars double stacked, which looks a bit scary but does give better aerodynamics, except at the ends. Where we can run double stack cars, there are very few clearance restrictions at all! There are rarely more than half the cars double stacked where we can run them, and well cars are often used in the the almost half of the country where double stacking can't be used!

Peter

[Anonymous]

QUOTE: Originally posted by M636C

QUOTE: Originally posted by futuremodal

QUOTE: Originally posted by M636C

QUOTE: Originally posted by foureasy

How much trouble would it be to get all full hieght stacks together instead of a mish mash low/high consist. Seems the added time required would surely
decrease fuel usage due to wind resistance.Am i wrong?

I wouldn't have thought that the ends of the containers would be close enough together on any of the double stack cars I've seen, to give a continuous flow around the upper containers. Given that there is at least one full truck length (say nine feet) between containers there will be considerable turbulence and drag, even if the containers are all double stack at the same height. There are a range of container heights from 8 feet to 9 feet 6 inches in general service, which gives the possibility of a three feet difference in height on adjacent double stack cars anyway.

While an Amtrak train with a rake of Superliners has small enough gaps between cars to be effectively streamlined, this is not the case with double stack cars.

Peter

Peter,

The stack n' half is designed for semi-streamlining, as it takes care of the space between the double stacked containers by adding a 20' container in that slot. The wells are connected by either a mini-spine on which the 20' rests, or a standard drawbar over which the 20' "floats" between the wells. The end trucks are 70 ton and the intermediate trucks are 100 ton.

OK, I've checked out the patent drawings! This will fit four more twenty feet containers on a bar coupled five pack unit, and the aerodynamics will be better, if not up to passenger car standards. But if you use articulated cars, you get the basic double stack five pack with four fewer trucks (which must be a saving, even if you need 125 ton trucks at the articulation). You could then add a sixth articulated platform by adding one more 125 ton truck to carry the extra four twenty feet containers. The extra length would be small and the purchase cost would surely still be lower, (you are still three trucks ahead) and although the aerodynamics will be worse, how much will that matter?

Have you run any wind tunnel tests? I don't know what the scale effects would be, but HO scale models would surely give you a comparison at pretty low cost!

Peter

Peter,

The stack n'half also allows the well cars to carry 160,000 lbs compared to articulated wells which only allow 120,000 lbs, give or take. How many times have you seen articulated well cars with two 20's in the well and nothing on top? That's because the unit has already maxed out on weight, and even carrying an empty on top can take it over the weight limit. So your load factor in weight is also improved with my design.

As for wind tunnel tests, you'll have to inquire at Greenbrier. It's their baby now.

[mvlandsw]

Hauling fewer empty cars would save more than streamlining. I see CSX intermodal trains running in both directions with half the cars carrying nothing.

[TH&B]

If aerodynamics are important, then go back to single stack articulated spine cars where the containers can be real close. If trains were to speed up dramaticaly this might be the way.

[M636C]

QUOTE: Originally posted by futuremodal

QUOTE: Originally posted by M636C

QUOTE: Originally posted by foureasy

How much trouble would it be to get all full hieght stacks together instead of a mish mash low/high consist. Seems the added time required would surely
decrease fuel usage due to wind resistance.Am i wrong?

I wouldn't have thought that the ends of the containers would be close enough together on any of the double stack cars I've seen, to give a continuous flow around the upper containers. Given that there is at least one full truck length (say nine feet) between containers there will be considerable turbulence and drag, even if the containers are all double stack at the same height. There are a range of container heights from 8 feet to 9 feet 6 inches in general service, which gives the possibility of a three feet difference in height on adjacent double stack cars anyway.

While an Amtrak train with a rake of Superliners has small enough gaps between cars to be effectively streamlined, this is not the case with double stack cars.

Peter

Peter,

The stack n' half is designed for semi-streamlining, as it takes care of the space between the double stacked containers by adding a 20' container in that slot. The wells are connected by either a mini-spine on which the 20' rests, or a standard drawbar over which the 20' "floats" between the wells. The end trucks are 70 ton and the intermediate trucks are 100 ton.

OK, I've checked out the patent drawings! This will fit four more twenty feet containers on a bar coupled five pack unit, and the aerodynamics will be better, if not up to passenger car standards. But if you use articulated cars, you get the basic double stack five pack with four fewer trucks (which must be a saving, even if you need 125 ton trucks at the articulation). You could then add a sixth articulated platform by adding one more 125 ton truck to carry the extra four twenty feet containers. The extra length would be small and the purchase cost would surely still be lower, (you are still three trucks ahead) and although the aerodynamics will be worse, how much will that matter?

Have you run any wind tunnel tests? I don't know what the scale effects would be, but HO scale models would surely give you a comparison at pretty low cost!

Peter

[Anonymous]

QUOTE: Originally posted by M636C

QUOTE: Originally posted by foureasy

How much trouble would it be to get all full hieght stacks together instead of a mish mash low/high consist. Seems the added time required would surely
decrease fuel usage due to wind resistance.Am i wrong?

I wouldn't have thought that the ends of the containers would be close enough together on any of the double stack cars I've seen, to give a continuous flow around the upper containers. Given that there is at least one full truck length (say nine feet) between containers there will be considerable turbulence and drag, even if the containers are all double stack at the same height. There are a range of container heights from 8 feet to 9 feet 6 inches in general service, which gives the possibility of a three feet difference in height on adjacent double stack cars anyway.

While an Amtrak train with a rake of Superliners has small enough gaps between cars to be effectively streamlined, this is not the case with double stack cars.

Peter

Peter,

The stack n' half is designed for semi-streamlining, as it takes care of the space between the double stacked containers by adding a 20' container in that slot. The wells are connected by either a mini-spine on which the 20' rests, or a standard drawbar over which the 20' "floats" between the wells. The end trucks are 70 ton and the intermediate trucks are 100 ton.

[adrianspeeder]

How aero is them wide noses anyway. Hmmm, maybe the F and E units had something.

Adrianspeeder

[M636C]

QUOTE: Originally posted by foureasy

How much trouble would it be to get all full hieght stacks together instead of a mish mash low/high consist. Seems the added time required would surely
decrease fuel usage due to wind resistance.Am i wrong?

I wouldn't have thought that the ends of the containers would be close enough together on any of the double stack cars I've seen, to give a continuous flow around the upper containers. Given that there is at least one full truck length (say nine feet) between containers there will be considerable turbulence and drag, even if the containers are all double stack at the same height. There are a range of container heights from 8 feet to 9 feet 6 inches in general service, which gives the possibility of a three feet difference in height on adjacent double stack cars anyway.

While an Amtrak train with a rake of Superliners has small enough gaps between cars to be effectively streamlined, this is not the case with double stack cars.

Peter

[rrnut282]

If I understand your question, it has to do with the ultimate destination of the containers. It's just not worth the time and effort to restack a train whenever they pick up or drop off along the way. It's far more efficient to pick-up a car or a string of cars rather than spot cars next to the loader so it can add or subract containers while the rest of the train waits. So far, the time wasted waiting costs more than the potential fuel savings and crew costs. Any extra time traversing a crew district means the possibility of a dog-catch crew which drives up the cost to provide transportation service to the container shipper.

[Anonymous]

QUOTE: Originally posted by foureasy

How much trouble would it be to get all full hieght stacks together instead of a mish mash low/high consist. Seems the added time required would surely
decrease fuel usage due to wind resistance.Am i wrong?

Good observation. That is one of the prime reasons behind the stack n'half.....

http://patft.uspto.gov/netahtml/srchnum.htm

(search for patents 6,546,878 and 6,510,800)

.....which you should see in about 10 or 15 years, knowing how slow railroads are to implement new equipment......

[Anonymous]

QUOTE: Originally posted by Mookie

QUOTE: Originally posted by macguy

Seems to me, that today with all the demand for intermodal, railways are just happy to have all the equipment they can get to try and meet demands.

Seems that issues like these will start to get fixed as newer equpiment comes on-line and the older stuff is slowly scrapped.

It wasn't so long ago that boxcars would all travel with the doors open, nobody thought anything of it until someone realized how much extra drag this was causing on the trains.....

I can't think of a time recently when I've seen a train go by and the doors of a boxcar have been open.

macguy - I scratch my head every so often when freight goes by and the boxcar doors are open. I wonder why they would invite people to ride inside like that. And I have seen it often enough that it isn't out of the ordinary any more. Probably will never know for sure!

Mook

Wow, that's quite interesting, Mook.

I can honestly say that I haven't seen a boxcar go by with open doors for a good number of years, which truly means one of two things.

1) For whatever reason the railways in my area are more aggressive in making sure these things are shut.

or

2) I'm not spending enough time trackside. [:)]

[Mookie]

QUOTE: Originally posted by macguy

Seems to me, that today with all the demand for intermodal, railways are just happy to have all the equipment they can get to try and meet demands.

Seems that issues like these will start to get fixed as newer equpiment comes on-line and the older stuff is slowly scrapped.

It wasn't so long ago that boxcars would all travel with the doors open, nobody thought anything of it until someone realized how much extra drag this was causing on the trains.....

I can't think of a time recently when I've seen a train go by and the doors of a boxcar have been open.

macguy - I scratch my head every so often when freight goes by and the boxcar doors are open. I wonder why they would invite people to ride inside like that. And I have seen it often enough that it isn't out of the ordinary any more. Probably will never know for sure!

Mook

[Anonymous]

Seems to me, that today with all the demand for intermodal, railways are just happy to have all the equipment they can get to try and meet demands.

Seems that issues like these will start to get fixed as newer equpiment comes on-line and the older stuff is slowly scrapped.

It wasn't so long ago that boxcars would all travel with the doors open, nobody thought anything of it until someone realized how much extra drag this was causing on the trains.....

I can't think of a time recently when I've seen a train go by and the doors of a boxcar have been open.

[Anonymous]

How much trouble would it be to get all full hieght stacks together instead of a mish mash low/high consist. Seems the added time required would surely
decrease fuel usage due to wind resistance.Am i wrong?