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Re: SD30

The Athearm GP30 was based on the EMD 'GP22' demo engine. EMD was going to market it as a GP22, but GM decided that GP30 was better as the 'number' was bigger that the '25' in GE's U25B! Marketing advertised '30 improvements' in the new GP30. They did not mention that the engine had 250 less HP when comparing it to the GE product! This pre-production unit was closer to the Athearn 'GP30' than a production unit, but was still not correct, even for that unit. The Athearn SD45 was based on pre-production drawings of the SD45. Other than the 'wide' body, it was quite close in the radiator area to the actual 'demo' units.

Jim Bernier

"Daniel A. Mitchell" wrote:

Reply to
Jim Bernier
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NOPE!

I've seen several photos of these beasts. Thre were 83 of these, built for the Vitoria A Minas Ry. in Brazil. They were indeed narrow gauge, 3'

6" IIRC. The EMD Flexicoil trucks were visibly DD, VERY similar to the DD trucks on the DD-35's in appearance. They were called, by EMD, a DDM45 ... perhaps among other things. So EMD considered them DD, and NOT (B-B)-(B-B). There was NO span bolster, and only two more-or less rigid truck frames visible per side.

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The reason they were DD was as I stated ... to get full use of the SD's power at lower speed. The smaller traction motors necessitated by the narrow gauge meant that six smaller motors could NOT consume the power generated by the locomotive at lower speeds. Hence eight motors were needed.

They most definitely did NOT have four separate trucks, but I suppose some kind of internal (to the truck) lateral motion device was likely included. It may have been included in the USA standard gauge versions as well, but stiff trucks was one reason these machines were not popular.

Dan Mitchell ==========

Brian Paul Ehni wrote:

Reply to
Daniel A. Mitchell

The narrow gauge motors would work just fine ... just not a lower speeds where the six smaller motors could not 'absorb' all the current coming from the big generator. So two more motors were added to make a total more in keeping with the generator's capacity . This extended the useful speed range downward to something more in keeping with service requirements. Just like a 'slug' in concept. More 'TE' at lower speeds. These were ore haulers, not passenger power.

Dan Mitchell ==========

Brian Paul Ehni wrote:

Reply to
Daniel A. Mitchell

If you look at my 12:02 post, you'll see I admitted to a brain fart, and we agree on the reason for 8 axles as opposed to 6.

Reply to
Brian Paul Ehni

I didn't get your second response until after I'd posted my response.

We all get moments like those ... rather more often as we get older! :-(

Anyway, I posted some additional info that pretty much resolves the issue.

Dan Mitchell ==========

Brian Paul Ehni wrote:

Reply to
Daniel A. Mitchell

I'd like to see photos of the Dash 8's they bought.

Reply to
Brian Paul Ehni

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