Canadian Railroads > A lot of power for an island

A CN Train on Prince Edward Island in June 1973 with five units with not to large of a train. There seemed like a lot of ups and downs as you can see in this shot. 

Robert Morris Photography

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Great shot from the Island.  Although five units looks like a lot RSC-13s had very little tractive effort.

KG

I bicycled several sections of that railroad about 10 years ago. I regret not going to see it in action when I was in New Brunswick in the late 70's.

kgmontreal Wrote:
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> Great shot from the Island.  Although five units
> looks like a lot RSC-13s had very little tractive
> effort.
>
> KG

Result of the A-1-A trucks?

PHall Wrote:
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> kgmontreal Wrote:
> --------------------------------------------------
> -----
> > Great shot from the Island.  Although five
> units
> > looks like a lot RSC-13s had very little
> tractive
> > effort.
> >
> > KG
>
> Result of the A-1-A trucks?

Indeed.

KG

Info at The Diesel Shop website says the A1A-A1A RSC13 weighed about 224,000 lbs and had 30,000 lb continuous tractive effort, while the comparable B-B RS1 weighed 240,000 lbs with 34,000 lbs t.e. I'd think that the A1A unit would have about 2/3 the t.e. of the B-B, but I guess not.

I'll bet there is an omission in the website, or something didn't get copied correctly somewhere.

An RS-1 that weighs 240,000 has ALL of its weight on its drivers, or 60,000 pounds per axle.  They say that weight gives 34,000 pounds of tractive effort.

If the RSC-13s weigh 224,000 TOTAL,  they would only have about 150,000 pounds on the DRIVERS!  That would take some really creative math to get 30,000 pounds of tractive!

So, I'll bet the RSCs weigh about 336,000 TOTAL, which would give 224,000 on the drivers, which incidentally gives the listed amount of tractive using the same formula that gave 34,000 tractive to the RS1. 

Why they didn't order them with six motors confounds me.   They could have had a real strong light footed unit with six motors and only 51,000 pounds per axle?
G

The RSC13's were only slightly stretched RS1's, so I don't see how they would be as heavy as you postulated. Hopefully a Canadian expert will weigh in with the correct numbers.

ExSPCondr Wrote:
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> I'll bet there is an omission in the website, or
> something didn't get copied correctly somewhere.
>
> An RS-1 that weighs 240,000 has ALL of its weight
> on its drivers, or 60,000 pounds per axle.  They
> say that weight gives 34,000 pounds of tractive
> effort.
>
> If the RSC-13s weigh 224,000 TOTAL,  they would
> only have about 150,000 pounds on the DRIVERS!
>  That would take some really creative math to get
> 30,000 pounds of tractive!
>
> So, I'll bet the RSCs weigh about 336,000 TOTAL,
> which would give 224,000 on the drivers, which
> incidentally gives the listed amount of tractive
> using the same formula that gave 34,000 tractive
> to the RS1. 
>
> Why they didn't order them with six motors
> confounds me.   They could have had a real strong
> light footed unit with six motors and only 51,000
> pounds per axle?
> G

They needed some very light axle loadings for the rather frail bridges.

CPR_4000 Wrote:
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> The RSC13's were only slightly stretched RS1's, so
> I don't see how they would be as heavy as you
> postulated. Hopefully a Canadian expert will weigh
> in with the correct numbers.

I don't want to pick a fight, but we do have to do some simple math, and what I posted was certainly NOT postulation!

34,000 pounds of tractive effort listed for an RS-1 that weighs 240,000 pounds total on drivers  is 14.1% tractive effort.
30,000 pounds of tractive effort listed for an RSC-13 that weighs 224,000 pounds on drivers is 13.3% which is pretty close.
30,000 pounds of tractive effort for an RSC-13 that weighs 224,000 TOTAL gives 150,000 pounds on drivers, which gives 20% tractive effort out of an axle that only has 37,500 pounds on it!

Whether these units came from Schenectady or Montreal doesn't matter, but an RSC13 that has tri-mount trucks instead of Bs, six axles instead of four, and by your admission IS longer, AND weighs 16,000 pounds LESS?
G
 

ExSPCondr Wrote:
-------------------------------------------------------
> CPR_4000 Wrote:
> --------------------------------------------------
> -----
> > The RSC13's were only slightly stretched RS1's,
> so
> > I don't see how they would be as heavy as you
> > postulated. Hopefully a Canadian expert will
> weigh
> > in with the correct numbers.
>
> I don't want to pick a fight, but we do have to do
> some simple math, and what I posted was certainly
> NOT postulation!
>
> 34,000 pounds of tractive effort listed for an
> RS-1 that weighs 240,000 pounds total on drivers
>  is 14.1% tractive effort.
> 30,000 pounds of tractive effort listed for an
> RSC-13 that weighs 224,000 pounds on drivers is
> 13.3% which is pretty close.
> 30,000 pounds of tractive effort for an RSC-13
> that weighs 224,000 TOTAL gives 150,000 pounds
> on drivers, which gives 20% tractive effort out
> of an axle that only has 37,500 pounds on it!
>
> Whether these units came from Schenectady or
> Montreal doesn't matter, but an RSC13 that has
> tri-mount trucks instead of Bs, six axles instead
> of four, and by your admission IS
> longer, AND weighs 16,000 pounds LESS?
> G
>  
But the RSC-13 didn't have Tri-Mounts. They had Alco/MLW A-1-A trucks with equal axle spacing and two powered axles.
How much does a traction motor weigh?



Edited 1 time(s). Last edit at 12/05/16 20:51 by PHall.

I understand light axle loadings for small rail and/or light bridges.

But why not power all the axles on your locomotive?  As you can see from all of the above, there is something wrong with the weight figures quoted on the RSC-13s.  

Now lets look at the rest of what I said in the first post.  Whatever the weight on drivers on the RSC-13 turns out to be, it would have had 350-400 horsepower per axle, same as an RS-1.  Now, you add two more motors, and the lightweight locomotive only has to transmit 250 horsepower per axle to the rail!

Two lightweight RSD-5s would have the same tractive effort as Three RSD-13s, with much less total weight and axles!
G

PHall Wrote:
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> > Montreal doesn't matter, but an RSC13 that has
> > tri-mount trucks instead of Bs, six axles
> instead
> > of four, and by your admission IS
> > longer, AND weighs 16,000 pounds LESS?
> > G
> >  
> But the RSC-13 didn't have Tri-Mounts. They had
> Alco/MLW A-1-A trucks with equal axle spacing and
> two powered axles.
> How much does a traction motor weigh?

Please tell us, how much lighter an A-1-A truck is than a Tri-mount with four motors in it?
G

To end all this speculating I went to the official CNR documents and can report the following:

RSC-13 light weight = 224,740 lbs
RSC-13 fully loaded = 238,415 lbs
Continuous tractive effort = 36,000 lbs

KG

Robert,
Just in case it got lost in all the discussion about weights and tractive efforts ("I didn't expect the Spanish Inquisition!"), this is a magnificent photo! The framing of the train is exquisite, the subject wonderful, and black-and-white really does something that colour doesn't. Thanks for posting this masterpiece!
Fred

ExSPCondr Wrote:
-------------------------------------------------------
> PHall Wrote:
> --------------------------------------------------
> -----
>
> > > Montreal doesn't matter, but an RSC13 that
> has
> > > tri-mount trucks instead of Bs, six axles
> > instead
> > > of four, and by your admission IS
> > > longer, AND weighs 16,000 pounds LESS?
> > > G
> > >  
> > But the RSC-13 didn't have Tri-Mounts. They had
> > Alco/MLW A-1-A trucks with equal axle spacing
> and
> > two powered axles.
> > How much does a traction motor weigh?
>
> Please tell us, how much lighter an A-1-A truck is
> than a Tri-mount with four motors in it?
> G

That's why I asked how much a Traction Motor weighed. I don't know.

> That's why I asked how much a Traction Motor
> weighed. I don't know.

Standard motors about 6000 lbs. each.

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If they put three of those locomotives on a very frail bridge, they might not have a bridge problem much longer. 

Jerry Pinkepank's Second Diesel Spotter's guide notes on page ALCO-238, that the 539 engined 1700-1734 were updated by removing the center axle on each truck, creating a B-B unit.