Should larger freight cars have six axles?

[dknelson]

If you read last month's Trains article on the Wisconsin & Southern you know that the regular increases in freight car loading weight have now reached such a point that short lines built even to decent Class 1 standards of 40 years ago are being slowly (and not so slowly) torn apart by their trains.
This is a problem throughout the US and Canada and a lot of rural grain elevators are facing problems because the rails that serve them are only busy seasonally and do not warrant being rebuilt with new ties and heavier rails (not to mention bridges and other infrastructure changes) yet the cars they are being sent are getting heavier and heavier, for excellent economic reasons of course.

What I wonder is if it is more economical to consider equipping heavier cars with six axles rather than the current four. There are some cars, such as Dept of Defense and other heavy duty flatcars that are already six axle, and back in the day the Virginian and N&W had huge battleship coal gons with six axles. It makes more sense to me to modify or replace the heaviest cars rather than rebuild -- or worse yet, abandon -- entire railroads.

I am no engineer and I just offer this topic up for (hopefully more informed then my own) comment.
Dave Nelson

[John Krug]

Six wheel trucks increase the cost and weight by a significant amount. They also increase the complexity of the braking system. They also are more likely to go on the ground in switching operations in the yards and industrial track. The increase in length poses interferences with the car bodies on car designs that already exist.
John

[jchnhtfd]

Six wheel trucks are a pain. I second all of John's comments on them. Plus, on any track work which is even remotely tight, not only do they derail more easily, they can damage track. Pick switch points. And so on.

For very heavy cars, in my humble opinion (and I bet someone disagrees!) a pair of four wheel trucks on span bolsters is only slightly more complicated to build and maintain, and much easier on the track (the biggest hassle is two extra pairs of side bearings to maintain...)

[CSSHEGEWISCH]

Two four-wheel trucks on a span bolster is slightly less complicated than a six-wheel truck and may be easier on the trackwork but it is still additional running gear that needs to be maintained. Although upgrading the branches will cost money, it is a more reasonable option than adding complexities to the running gear of covered hoppers.

[jchnhtfd]

Amen, Paul! Oh, quite, in fact! I didn't mean to advocate putting covered hoppers or much of anything else on span bolster systems! The only time I'd go for that is when you've got something which can't be broken up into component bits (like big electrical equipment). The mainentance headache is too much for the short distances involved.

[samfp1943]

This is going to be a real problem, in particular for the shortline industry as shippers demand the ability to ship more in cars from locations on secondary lines that are not up to mainline weiight standards..I will get really expensive and potentially reasonable to expect some levels of abandonment as short line are unable to justify the added expense of upgrading track to 285,000# or greater.. LIke most things it boils down to the economics of the situation.

[samfp1943]

This is going to be a real problem, in particular for the shortline industry as shippers demand the ability to ship more in cars from locations on secondary lines that are not up to mainline weight standards..I will get really expensive ,and potentially reasonable to expect some levels of abandonment as short line are unable to justify the added expense of upgrading track to 285,000# or greater.. LIke most things it boils down to the economics of the situation.

[John Krug]

There is another solution. Since most short lines are termination points rather than bridge lines, work out arrangements with the receivers to accept reduced shipments such as the original 100T - 263,000# RRL rather than the present @286,000#. Might even go back to the 70ton RRL of 210,000#.

[ndbprr]

If you read last month's Trains article on the Wisconsin & Southern you know that the regular increases in freight car loading weight have now reached such a point that short lines built even to decent Class 1 standards of 40 years ago are being slowly (and not so slowly) torn apart by their trains.


Well Yeah! That is what maintenance is all about. Don't forget those lines aren't forty years old they probably go back to the days of steam engines and the infrastructure was designed (read ballast and bridges) to support axle loadings of steam. Somthing is amiss if car weights are now tearing it up. My first opinion is deffered or reduced maintenance and it gets railroads every time.

[waltersrails]

I agree 6 ax would be a problem. The only thing is it be cool to see.

[Junctionfan]

Interesting discussion. To me, six axles equalls specialized and non standard trucks which means extra costs. I know of only 1 maybe 2 railcar types that use 3 axles trucks. The first are those aluminum resinate tankers with CELX reporting marks. The other I believe is a series of depressed flats owned by CN which has 2 sets of 3 axled trucks on both ends for a total of 12 axles.

I would find it interesting if cement or something heavy like that, could be put into a 3 or 4 bay in length; covered hopper with a 2 axle truck in the middle and actually designed as a 2 bay hopper. Not too sure how the railroad industry would react but something interesting to ponder-maybe someone with more engineering or practical first-hand experience would like to comment please.

[Anonymous]

why not just use the short 2 bay cement hoppers rated at 100 ton that works out to 4 axles per 100 ton insted of 6 per 200 ton glennbob

[Anonymous]

In the case of a freight car what matters is full/tare ratio (or load/tare - whichever). The higher it is - the more freight the railroad carries - instead of equipment.

Obviously it is better to haul a ton of coal, then a ton of running gear.

[TH&B]

But if that ton of running gear can make the car carry another 10 tons there may be a logic to do it, right? For some reason it makes sense to have 6 axle locos but not in freight cars?!?!? ((personaly I beleive in the two axle truck for everything including locos and even model trains hehehe))

I beleive the real short term solution is to use the cars we have but, perhaps especialy load them lighter. I seem to see this done alot anyways.

[Junctionfan]

That reminds me of what I have heard folk decribe the DDA40X; a track straightener. I guess the 4 axle per truck thing wasn't as appealing as some first thought.

[PNWRMNM]

Customers will not load cars light as most bulk rates are per car so your per ton cost increases.

Class I main lines will handle 286K 4 axle cars so they will continue to publish per car rates based on full loads.

Six axle trucks, by themselves, that is holding gross weight on rail constant, reduces carrying capacity and increases tare weight which no one wants. This will not fly. Six axle trucks and cars 429,000 gross weight gains you nothing by the complexity of six axle trucks, so I doubt anyone will try it.

Short lines that try to embago heavy cars will find themselves left with little or no traffic in those commodities. They need to maintain good tie condition and install good ballast. This is cheaper than heavy rail and is a prerequsite to supporting heavier rail if they can get it. If rail is less than 112# may need to limit speed to 25 mph or less with heavy cars, even with good ties and ballast.

Lines with rail lighter than 112/115# and heavy cars are in an bad fix becuase the rail was not designed to support the weight that is being placed on it. A typical car of 1920 was about 132,000# if I recall correctly, less than half of 286,000#.

Mac

[Modelcar]

...Most simple solution in my opinion {as a non expert}, has already been mentioned above and I agree....Load conventional covered hoppers lighter and or arrange to use the 2-bay covered hoppers to produce the lighter load for the track. Can't the regulations and paper work be amended to accomplish such an act when it's necessary to do to continue the business. Sounds to me better than doing away with the business and moving it to trucks, etc.....

[Anonymous]

1. If the Class I's continue to pressure the shortlines/branchlines out of business, the industry will continue to lose customers and register complaints from politicians. The latter is already finding its way into proposed legislation.

2. An aquaintance of mine involved with shortline operations avers the the claims of 286k cars running shortlines out of business are greatly exaggerated. His line gladly accepts 286k cars, they just run them at 10 mph max.

3. More axles does solve the problem of having too much weight concentrated on four axles, but does not solve the problem of bridge weight restrictions, a problem on many shortlines.

4. More axles would allow higher load weights (see Rail Whales discussion) on the Class I mainlines, if only the FRA would allow it.

[TH&B]

I saw a train of 118 cars in length held up hours on a double track main because it had 1 ((that's one)) double stack stand alone car so it couldn't clear a bridge. The train was waiting to be rerouted and there was empty wells in the consist. I kid you not and I'm sure it will even happen again.

So to make one double stack load efficient it seems ok to delay a whole train. This makes me refuse to beleive that when you have the railway and you have the cars, but you can't run it because you realy need to load each car with 12 tons more on a short line but a class one can waste efficiency away. In fact most loaded cars I ever see are not loaded 286k, the odd one is but most are not. Occasionaly but even more rarely I see a 315k car.

I get my info from inbound and outbound train consists from CSX Frontier Yard NY.

[jchnhtfd]

Junction -- that CN class of overweight flat cars is something else, isn't it? They are seen in Peterborough (ON) from time to time at the GE plant.