Who will be the first to kit bash that? [:D]
Only the time I managed to derail every car except he caboose on my Lionel set.
–Austin
Could that be an adaptation for tight radius turns?
As the thread later indicates, those units are modified EX-CONRAIL locos operating in Brazil. Not something one would see on a US railroad - but very interesting none the less.
The extra axles lighten the load per axle. Having four trucks serves to shorten the rigid wheelbase.
A closer investigation will reveal these units are now riding on narrow gauge trucks… [:O]Thats why the truck change.
Probably significantly reduces the tractive effort as well.
They also have similarly modified SD40-2, SD40T-2, and SD45-2 locos. I was starting to try to build one in standard gauge, but haven’t quite figured out how to make the drive work the way I want.
http://www.rrpicturearchives.net/modelList.aspx
To find these photos, scroll down to “Rebuilt EMD”. The first locos are these. If anyone has any good ideas on how to bash a respectable drive for one of these, please share!
Dave,
The TE remains the same if the weight is not reduced. The ‘axle loading’ is now lower, but the total wieght on the drivers is still the same. The other advantage is that there are more tractions motors to soak up all of tha electrical energy generated above the frame level. At low speeds this is an advantage, but becomes a penalty as the speed increases(now you have thirsty traction motors sucking the main generator down). In most US practice, the axle loading is in the 65,000-70,000 lb range.
Jim
That is just completely WHACKED!
Big diesel, narrow track…Cool
yep these are modified for narrow gauge, meter gauge to be precise. The double trucks help not to crush the track. If you think these look odd, you should see the modified SD70’s and Dash units that have been shipped there, those dwarf the tracks!
The tractive effort might actually increase if the individual traction motors had the same power as the US gauge traction motors they replaced. The extra axle would allow more tractive effort to be generated as long as the motors cojuld withstand the current.
Almost certainly reduces the tractive effort PER AXLE. However, unless the entire locomotive has been lightened (improbable) the TOTAL tractive effort (which is driven by total weight) would remain pretty much the same.
Note that the wide gauge units also have more axles (Do-Do rather than Bo+Bo-Bo+Bo,) presumably out of deference to the inability of Brazilian track structure to handle U.S. axle loadings.
Chuck