Is the weight of current locomotives all from the components (engine, computer, trucks, etc.) or is there weight added to each like counterweight s on cranes? Also speaking of new locos, which road orders the heaviest and lightest ones and why for each decision?
Did I post a question that has stumped the board or what? I thought at least one person would have know the information.[%-)]
Hey, it’s a pretty nice day out! Everyone is probably out watching trains![:D]
Check back after the sun goes down…
The heaviest I have heard of are CSX’s newer ACs at about 216 tons, all railroads are ordering locomotives near the same weight, I don’t think anybody orders them lighter than about 206 tons anymore. Of course this keeps newer power off many branches. The still add ballast to the locomotives. This is desireable in order to balance the locomotive front to rear. Ballast is normally added at the rear of the locomotive to balance the heavy cab at the front.
Due EMD and GE give the railroads many options when it comes to engine wieght? I thought this was a fixed specification with a give locomotive model.
Is there a particilar reason why CSX would order the heaviest locomotives? And what is the material builders use to add ballast weight to them?
When a locomotive is built their builders can add weight inside the frame, the material of choice is concrete in this case. To ballast an existing locomotive, then sheets of steel are used. If one gets a chance, look along the catwalk of any CSX SD70MAC including the ex-Conrail units. The treads are different from that used by EMD. This appplies to 700 series SD70MACs. The later 4700-4830 series units were built to the heavier weights CSX desired. Some 700s had been built with the extra weight, but using sheet steel ballast, so CSX could lighten the units if the added weight didn’t work out. CSX however liked the results and their later SD70MAC’s and SD70MACe’s were built at maximum weight. When CSX goes back to EMD for more SD70MAC2s you can bet that they’ll be around the 250 ton(500,000 lb.) mark. They do wonders for CSX’s less than perfectly maintained track!
CSXT has many severe grades; and the purpose of the added weight is to prevent trains from stalling on those grades. The additional weight makes relatively little difference at speeds of around 10 mph and greater; however it significantly increases tractive effort as speed drops beneath that level. Consequently a consist of “heavy” units can be relied upon to move a longer/heavier train than a consist of standard-weight units can be relied upon to move. CSXT has not acquired a new standard-weight unit since 2000. Steel is used for the additional weight; and the location of the added steel varies depending on the locomotive model.
As a general rule of thumb, locomotives will generally weigh in at 30-35 tons per axle, with the average 4-axle locomotive around 125 tons and a 6-axle locomotive around 200 tons. As pointed out in some of the above posts, there are exceptions where the track structure can handle the weight. BRC was noted for its heavy 4-axle locomotives, with its original GP38-2’s (490-495), which were used as hump pushers, weighing in at about 140 tons.
Most North American locomotives are ballasted for extra weight. Frames are also built heavier than structurally necessary to provide some of the extra weight.