Edit post

Edit your reply below.

Post Body
Enter your post below.
[quote]QUOTE: Originally posted by beaulieu [quote]QUOTE: Originally posted by futuremodal [quote]QUOTE: Originally posted by jeaton And the cost figures to prove your assertion are found where? [/quote] Start with TRAINS March 2006 issue, the HAL article. Then use a comparative check of the load factor numbers provided by the author with a similar hypothesis plugging in the six axle concept. You can plug and play any number of hypothetical combinations. Try this one for size. According to the article, the 4 axle 286k car increases lading by "10 to 15 percent" over the 4 axle 263k car, while "weight on the rail grows by only 8.75 percent". Although not specifically mentioned in the article, the 286k has roughly 35 tons on each axle while the 263k has roughly 33 tons on each axle, and they are using 36" and 33" wheels respectively. With a six axle 300k car using 28" wheels and 25 tons per axle, you get the same "10 to 15 percent" lading increase over the 263k car, but actual weight on the rail decreases by 33 percent! The article also states that shortlines and regionals represent 30% of the rail network, and would need $7 billion to upgrade their tracks for the 35 -39 ton axles. From that you can infer that it has cost the other 70% of the rail network roughly $24 billion to upgrade their tracks for the 35 - 39 ton axles. $30+ billion total, soley for HAL! I can bet you it wouldn't cost a fraction of that if they had instead gone spread axle on their new higher lading freight car purchases/leases. [/quote] I like the way that you slide in your own opinions as though they were part of the article Dave. The three axle truck you suggest using, would cost significantly more than a larger two axle truck, would be heavier (increasing the empty weight of the car), would have a longer wheelbase even with the smaller wheels (increasing flange and rail wear) or if a radial design would require more maintenance and be much more expensive. [/quote] Well, first of all no one is confusing my opinions with the HAL article, because the HAL article didn't even touch on the spread axle alternative. I'm not sure how you can infer that as my presentation of the article's data. Speaking of sliding in opinions, your statements that the three axle truck would cost "significantly" more is purely subjective, because we don't have any actual cost comparison numbers to analyze. Yes, three 25 ton axles would cost more than two 39 ton axles, but not by much, maybe 25% more, because each 25 ton axle presumably costs less than each 39 ton axle. The use of independent suspension would also raise the costs of trucks, but that would apply to two axle trucks that might use independent suspension as well as three axle trucks. The trade-off comes in greater ride quality for the load. And you should also point out that the 125 ton truck is much heavier than the 70 ton truck and therefore also increases the light weight of the car, yet because it allows for larger revenue lading it increases the load factor. That same line of reason also would apply to the three axle truck, e.g. the greater the accumulated gross weight limit the greater the increase in lading potential. And I am suprised you include the "increase in rail and flange wear" argument (due to the longer wheelbase of a three axle truck) in the same sentence as the reference to the radial steering, because it is precisely the radial steering that would reduce rail and flange wear, and in fact would make a three axle truck less wearsome to the rail and flanges than a standard three piece two axle truck. Therefore, if the truck has radial steering, the length of the wheelbase is meaningless in regard to rail and flange wear. It may even be that the savings in rail and flange wear from using radial steering would offset the maintenance costs of radial steering technologies. And we well soon start to see radial steering mechanisms used on two axle trucks. The RailRunner technology already employs radial steering on it's two axle trucks. The bottom line is that a three axle truck at 25 tons per axle would allow for lighter (and thus less expensive) rail and rail components than the proposed 39 ton axle. HAL is for the birds.
Tags (Optional)
Tags are keywords that get attached to your post. They are used to categorize your submission and make it easier to search for. To add tags to your post type a tag into the box below and click the "Add Tag" button.
Add Tag