modern EMD truck suspension?

The real ones look like giant air bags.

I Never considered they maybe full of somethin'.....

Perhaps this will help? The rubber pads are secondary springs
Gunny

 WOW Gunny, yes. thank you!

"rubber secondary springs"

Obviously it is way too complicated to expelling here, plus all the typing involved. Suffice it to say, those four big rubber/steel chevrons definitely BELONG THERE, as they support the weight of the unit. However, the tractive effort is NOT transmitted through those 4 chevrons.

 HW, Well now you've got me thinking....

the weight of the engine sits on those secondary springs??

the tractive effort your describing transfers mainly or only to the pivot pin then?

 The secondary springs have pins on top. How do they allow the truck to turn? Do the pins slide in grooves? Do they just flex?

 

Joe,

I could be wrong but I assumed that all the CSX SD70ACe had non-radial trucks, not the HTCR-4 radial truck used in the Union Pacific & many BNSF SD70ACe locomotives.

http://www.railpictures.net/vi...d=123941&nseq=15

These are just my opinion,

Thanks,

Naveen Rajan

Naveen,

 I've been reading different forums and see that posted too. There's a less expensive non- radial truck option.

 I thought it still had the basic same platform? I've also read something about users making the radial truck rigid (non-steering)??

Joe,

I wasn’t aware of the differences until a month ago when I saw each of the assembled trucks, in person before they were assembled under a locomotive. According to the engineer who escorted me through the EMD facility, the HTCR was a higher-cost option. The front & rear axles had linkages connecting them allowing passive steering through curves. HTCR-4 also had a linkage around the massive pin under the frame that seem to allow the truck to shift sideways a little. The non-radial truck had a lot fewer, simpler linkages connecting the end of each axle, independently to the truck casting.

And it was not just the linkages. There were differences in the truck casting depending on the specific linkage connection points.

For an O-Scale or G-Scale model locomotive I am not sure if the axles actually have a steering mechanism instead of just capturing the look of the appropriate linkages on the side of the trucks (mainly below the truck casting). Erik’s post on the BHP Iron Ore SD70ACe on the 2-rail forum has images of the non-radial truck which might be more appropriate for a CSX SD70ACe. You could compare them to the images you posted at the beginning of this thread.

These are just my opinion,

Thanks,

Naveen Rajan

Guys, EVERY SINGLE diesel electric locomotive transmits it tractive force through the bolster center bearing, one way or another. The Radial truck design has a massif "center pin" to transmit all that force from the Radial Truck, but it all winds up going into the locomotive under frame through the two center bearings or center pin, in the case of the radial truck design.