Canadian Railroads > Why did CN Buy SD40's Without Dynamic Brakes?

CN initially purchased SD40's with dynamic brakes.  Subsequently, they switched to ordering this model without dynamic brakes.
What was the railroad's rationale for this change?
ALLEN  

krm152 Wrote:
-------------------------------------------------------
> CN initially purchased SD40's with dynamic
> brakes.  Subsequently, they switched to ordering
> this model without dynamic brakes.
> What was the railroad's rationale for this
> change?
> ALLEN  

CN made its first purchase of SD40's specifically for serving the coal mine at Winniandy on the Grande Cache Subdivision which involves grades of 2.2 percent or more. These operated between the mine and the port of Vancouver BC.

CN was a late convert to the use of dynamic brakes, and ordered locomotives for general service across Canada without DB. This included GP40-2L's for fast intermodals and many orders of SD's.


 

If I'm not mistaken, some of CN's C630M's had d/b and some didn't. Don't know about the M636's.

CN seemed to run on the same assumption that many other "flatland" railroads like the Missouri Pacific did. If you don't run in the mountains, you don't need dynamic brakes.

Unlike CP, CN did not have a mainline grade stouter than 1.5 per cent.  Perhaps they felt that dynamic brakes were unnecessary.

Chris Rye.

eminence_grise Wrote:
-------------------------------------------------------
> krm152 Wrote:
> --------------------------------------------------
> -----
> > CN initially purchased SD40's with dynamic
> > brakes.  Subsequently, they switched to
> ordering
> > this model without dynamic brakes.
> > What was the railroad's rationale for this
> > change?
> > ALLEN  
>
> CN made its first purchase of SD40's specifically
> for serving the coal mine at Winniandy on the
> Grande Cache Subdivision which involves grades of
> 2.2 percent or more. These operated between the
> mine and the port of Vancouver BC.
>
> CN was a late convert to the use of dynamic
> brakes, and ordered locomotives for general
> service across Canada without DB. This included
> GP40-2L's for fast intermodals and many orders of
> SD's.
>
>
>
 CN's GP9's were equipped with dynamic brakes.  Did they subsequently have some kind of epiphany?
ALLEN

I can't speak for the CN but on the C&NW there were no locomotives purchased with dynamic brakes until they ordered 135 SD40-2s in about 1974-75.  At the time the locomotive maintenance dept. had an inordinate influence on what was needed and hence purchased.  Their opinion before this time was that it was just something else that had to be maintained. C&NW didn't have a lot of heavy grades and could pretty much get away with these decisions.  One of the biggest reasons for changing their policies was as a fuel conservation measure. 

Nassau Wrote:
-------------------------------------------------------
> I can't speak for the CN but on the C&NW there
> were no locomotives purchased with dynamic brakes
> until they ordered 135 SD40-2s in about 1974-75. 
> At the time the locomotive maintenance dept. had
> an inordinate influence on what was needed and
> hence purchased.  Their opinion before this time
> was that it was just something else that had to be
> maintained. C&NW didn't have a lot of heavy
> grades and could pretty much get away with these
> decisions.  One of the biggest reasons for
> changing their policies was as a fuel conservation
> measure. 

Also, the roads they pooled power with, notably UP, wanted units with dynamic brakes.  This same reason was why
MP ordered SD40-2's with dynamics after eschewing them for years.  

Nick Tharalson,
Marion, IA

Think the MP dynos were because of the DRGW coal trains:) Even got the first few with mars lights.

Posted from iPhone