Eastern Railroad Discussion > SD70ACe/SD70M2 platform

Does anybody know why EMD went with the 80/90 series platform and body for the new 70 series? Did they need the 80/90 series' huge radiator section for Tier II compliance? That was the only reason I could think of, since it seemingly would have made more sense to stick to the 70M/70MAC platform, as there are a couple thousand of those already on the road, as compared to a paltry number of 80/90s. Or is EMD hedging their bets that the H engine will be back? Does anybody have a guess what the Chinese units might look like?

I was under the impression it was a totally new platform.

I believe it is a totally new platform…An SD70ACE measures 74’3’’, while an SD80/90MAC measures 80’2’’.

Ok then, I stand corrected. They DO look awfully long though. Regardless of the frame length, they still used the body, radiator setup and equipment layout more like an 80/90 series.

While the equipment layout is similar between the SD70ACe/SD70M-2 and the SD80MAC/SD89MAC/SD90MAC models, the SD70ACe/SD70M-2 locomotices are built on a completely new platform. The overall length for the SD70ACe/SD70M-2 is 74'3", while the SD80MAC/SD89MAC/SD90MAC models measure 80'2" overall.

The SD70ACe/SD70M-2 units use an all new cab/nose, different radiator size, and the truck options are either the new rigid HTSC or radial HTCR. The SD80MAC/SD89MAC/SD90MAC models used the HTCR-II trucks.


Chris Toth

Chris, I wonder when the ES40DC's will arrive? Also, is there any word on further orders of EMD and GE locos? Also, is NS considering AC motored locos? Thanks in advance.

Last I heard, the ES40DC's were scheduled for late December or early January delivery.

Nothing confirmed yet for 2006.


CRT

EMD did go with an entirely new platform for the SD70ACe and SD70M-2, some similarity to the SD90-series but different enough, probably for manufacturing simplicity. Remember, the SD90-series were actually TWO platform designs ... the "original" SD9043ACs for UP, CP and CEFX and the first 22 UP SD90ACs and 4 CP SD90ACs (6000 HP), and the last 40 "phase 2" SD90ACs for UP.

If you ever get the chance to look closely, you'll see the differences.

The "original" platforms were actually one-piece between pilot plates, with the fuel tanks bolted to the bottom of the frame. The "phase 2s" were a large platform center-section-with-integral-fuel tank (welded on) with "stub" frames beyond the tank ends (supporting the cab and radiator ends) welded onto the center section. It looks like the SD70ACe and SD70M-2 are single (one large welded assembly) end-to-end.

The large "winged" radiator sections on the SD70M EPA Tier 2 units and the EPA Tier 2 SD70ACe and SD70M-2 are part of EMD's emissions package.

Also, a design requirement for the 90-series (as was the case with the GE 6000 HP and their related 4400 HP "convertibles") was the big 6000 gallon fuel tank, necessary to make the 6000 HP units equivalent in operating range to a 4000-4300 HP unit with a 4500 gallon fuel tank. That's why the 90-series were longer yet than the others.

The Chinese 6000s will likely look very export-like, be much lighter than North American units, have smaller fuel tanks, and rumored to have cabs at both ends.

Electro-Motive Diesel is labelling their Chinese units as JT56ACe ... go to:
http://www.gmemd.com/en/locomotive/international/jt56ace/
for a side drawing.

From the above EMD-international web site.

Looks like a modified version of the domestic HTCR-4 truck used under SD70ACe's and SD70M-2's ... compare the length of the trucks to the fuel tank, and you can see the fuel tank is much shorter than any of the domestic 90- or 70ACe/70M-2 models!

Looks like another "packaging miracle" from EMD as were the Class-66 and brethren for the UK and now the rest of Europe ... when EMD put 3000 HP into a clearance package suitable for the Motherland of all railways.

---

NSDash9 Wrote:
-------------------------------------------------------
> The SD70ACe/SD70M-2 units use an all new cab/nose,
> different radiator size,
> Chris Toth


Not entirely new... the cab was used previously on the Phase II SD90MACs (UP and CN), and IIRC, one Phase II SD90MAC had the newer radiator compartment (i.e, two fans, etc)

The SD70ACe/70M-2 cab may look the same externally as the cab on the phase 2 SD90s ... but it's not the same cab.

First, all of the 90-series cabs were "isolated" cabs, mounted on rubber bushings to reduce vibration from the underframe. Have heard that those isolation mounts contributed mightily to many ride complaints from crews. You'll note that EMD quit building isolated cabs ... the SD70ACe/70M-2 cabs are solidly welded to the platforms.

Second, the interior arrangement is different.

Yes, the windshields and "squared off nose" angularity are the same ... that's all.

Wasnt the SD70ACe/SD70M-2 platform copied from the SD89MAC ALpha? I did a comparison a few days agoi and they to me all look the same. Am i right?
railfan1 out

Structurally ... no. The SD89AC (GM or EMDX 92) was built on the same SD90AC phase 2 platform as the 40 phase 2 UP SD90ACs. The difference was merely the engines ... the 90 and 91 have the 16-cylinder H engines, the 92 has the 12-cylinder H.

The phase 2 SD89/90AC platform was supposed to be intended by EMD to be their "platform of the future", but things changed after the 6000 HP market failed to take off.

The SD70ACe and SD70M-2 platforms are much different.

Thanks greendot
railfan1 out

Also, while the radiator compartment may appear to be the same bewteen the phase II SD90MAC units and the SD70ACe/SD70M-2 models, they are different. The radiator compartment of the phase II SD90MAC units is longer and the grille arrangement is also different.


Chris Toth

greendot Wrote:
-------------------------------------------------------
> The SD70ACe/70M-2 cab may look the same externally
> as the cab on the phase 2 SD90s ... but it's not
> the same cab.
>
> First, all of the 90-series cabs were "isolated"
> cabs, mounted on rubber bushings to reduce
> vibration from the underframe. Have heard that
> those isolation mounts contributed mightily to
> many ride complaints from crews. You'll note that
> EMD quit building isolated cabs ... the
> SD70ACe/70M-2 cabs are solidly welded to the
> platforms.
>
> Second, the interior arrangement is different.
>
> Yes, the windshields and "squared off nose"
> angularity are the same ... that's all.


The SD90Mac Phase II cab was the first to use the BLE-ARR control stand... so interior arrangement should be similar... and the cabs may not be mounted on rubber mounts, but they are the same sheetmetal, thus, the same cab...

Also, as per my original post, one SD90MAC was modified with the newer radiator compartment... I did not say they all were...

Robbman Wrote:
-------------------------------------------------------

> The SD90Mac Phase II cab was the first to use the
> BLE-ARR control stand... so interior arrangement
> should be similar... and the cabs may not be
> mounted on rubber mounts, but they are the same
> sheetmetal, thus, the same cab...

This is incorrect, all Phase II 90MAC's were built with EMD designed desktops, both CP and UP's, The BLE designed stand did not make a appearance untill the 5100 series UP SD70M's

I also would like to ask you to take a look a diagram of the layout of the Phase II EMD Isolated cab, as compaired to the newer cab, The structure and layout is much differnt betwen the two.

They do look very simular though, and it would not be hard to say that one design was based off the other.

greendot Wrote:

> <snipped>

> The Chinese 6000s will likely look very
> export-like, be much lighter than North American
> units, have smaller fuel tanks, and rumored to
> have cabs at both ends.
>
> Electro-Motive Diesel is labelling their Chinese
> units as JT56ACe ... go to:
> http://www.gmemd.com/en/locomotive/international/j
> t56ace/
> for a side drawing.


The character "J" in the model number means two cabs. A single cab version would be a GT56ACe.

BothanSpy Wrote:
-------------------------------------------------------
> Robbman Wrote:
> --------------------------------------------------
> -----
>
> > The SD90Mac Phase II cab was the first to use
> the
> > BLE-ARR control stand... so interior
> arrangement
> > should be similar... and the cabs may not be
> > mounted on rubber mounts, but they are the
> same
> > sheetmetal, thus, the same cab...
>
> This is incorrect, all Phase II 90MAC's were built
> with EMD designed desktops, both CP and UP's, The
> BLE designed stand did not make a appearance
> untill the 5100 series UP SD70M's
>
> I also would like to ask you to take a look a
> diagram of the layout of the Phase II EMD Isolated
> cab, as compaired to the newer cab, The structure
> and layout is much differnt betwen the two.
>
> They do look very simular though, and it would not
> be hard to say that one design was based off the
> other.
>
>
>

The BLE-ARR (note the -ARR) stand isnt' used in the UP 5100 series 70Ms (nor on NS' similar 70Ms)... if it were, these would have been built without porkchop windows (the BLE-ARR stand effectively blocks the lower portion of the porkchop, making it useless. Check out interior photos of a SD70ACe/M-2)

I've always ben under the impression that the Phase 2 SD90MAcs were the testbeds for the BLE-ARR stand (used in the SD70ACe/M-2)...

Robbman Wrote:

>
> The BLE-ARR (note the -ARR) stand isnt' used in
> the UP 5100 series 70Ms (nor on NS' similar
> 70Ms)... if it were, these would have been built
> without porkchop windows (the BLE-ARR stand
> effectively blocks the lower portion of the
> porkchop, making it useless. Check out interior
> photos of a SD70ACe/M-2)
>
> I've always ben under the impression that the
> Phase 2 SD90MAcs were the testbeds for the BLE-ARR
> stand (used in the SD70ACe/M-2)...
>
>
>


Have you even been in any of these engines?