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Which Ran Faster - Dash 8-40b or RS-1 ?

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  • Member since
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  • From: Dearborn Station
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Which Ran Faster - Dash 8-40b or RS-1 ?
Posted by richhotrain on Saturday, September 19, 2015 8:27 AM

I ask this because I just lubed the gears and drive train on a Dash 8-40b and got it running faster, matching the speed of its two identical mates. But, my RS-1 yard loco easily outran all three Dash 8-40b locos.

I would have thought that the opposite would have occurred.  

All four locos are Atlas HO scale locomotives.

Any thoughts or comments?

Rich

Alton Junction

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Posted by dehusman on Saturday, September 19, 2015 10:08 AM

richhotrain
ask this because I just lube the gears and drive train on a Dash 8-40b and got it running faster, matching the speed of its two identical mates. But, my RS-1 yard loco easily outran all three Dash 8-40b locos. I would have thought that the opposite would have occurred. All four locos are Atlas HO scale locomotives. Any thoughts or comments?

The performance of model locomotives are not in any way proportional to the prototype's performance.  If you think about it a model of a 1000 hp engine might have the exact same motor, gears and wheels as a model of a 4000 hp engine.

If the RS1's gearing is faster or the motor turns at a higher rpm then it will go faster than the B40's.

Where this is apparent is in some cases a 4 axle switcher model might be able to pull as many or more cars as a big articulated steam engine.

Dave H. Painted side goes up. My website : wnbranch.com

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Posted by richhotrain on Saturday, September 19, 2015 10:13 AM

Thanks, Dave, that is good to know.  I am satisfied that the once slower Dash 8-40b now matches speeds with its two matching mates, post-lube job.  I will leave it at that.

On the prototype, though, I have to believe that the Dash 8-40b runs faster than the RS-1.

Rich

Alton Junction

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Posted by zstripe on Saturday, September 19, 2015 10:28 AM

Rich,

In the Prototype the dash 8 had more horsepower, different wheel size and gear ratio.

In Your Models: Although horsepower is not an issue...the gear ratio verse's max rpm current draw at 12volts reflects the top speed. The models You have, are identical in gear ratio, drive axle's, worm and gear set.....what is different is the motor....they are not the same #, I'm guessing the RS has a higher rpm max motor than the others. That is for the one's made in China. There also is a RS 1 that was made in Japan that has a different driveline/gear ratio, motor, which also could be the one You have. They don't have the spec's for those, just part number's.

If You would like to compare #'s, here's a link:

http://www.atlasrr.com/hoparts.htm

Take Care! Big Smile

Frank

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Posted by richhotrain on Saturday, September 19, 2015 11:05 AM

For what it's worth, my RS-1s were made in China.

Rich

Alton Junction

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Posted by dehusman on Saturday, September 19, 2015 12:17 PM

richhotrain
On the protptype, though, I have to believe that the Dash 8-40b runs faster than the RS-1.

Not necessarily.  B40-B's probably are geared and have their engines set to go about 70 max.  RS-1's that were equipped to haul passenger trains could hit 80-100 mph.

Its all about gearing.  A GP40 on a freight road can hit 70 max.  A F40 for a passenger line (same engine, trucks, etc) can hit 110 mph.

Dave H. Painted side goes up. My website : wnbranch.com

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Posted by rrinker on Saturday, September 19, 2015 9:17 PM

So, probably are that Dash 8 40B's (made in China that is).

If running under DCC, you can set the top speed (CV5) to limit each loco to a prototypical top speed. Now, typically a 40B might be geared for a slightly higher top speed than an old RS-2, but as Dave explained, this wouoldn;t necessairly always be true. But if the ones used by your railroad were geared such that an RS-1 had a 67mph top speed and a 40B had a top speed of 78mph, you can use CV5 to adjust the models to replicate this.  The closest you usually get out of the box with models are the settings with QSI and MTH decoders that use each speed step in 128 step mode as a 1 smph increment, but that gets them up to 128 mph at full throttle, which is too fast for most. Speed on DC using the same power source is going to depend on the motor and gears used - even locos from the same maker don;t always have the same motor (Atlas has changed over the years, the old RS units were Kato built, then Atlas had their own motor, and that was also changed at least once over the years. Gear ratios, anyone's guess if they exactly copied the Kato each time or altered it. Perhaps you've seen the threads on P2K E units - Since Walthers did re-releases, they've used multiple gear ratios, so none of them run together despite all the rest being the same.

                --Randy


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by steemtrayn on Tuesday, March 15, 2016 4:12 AM

dehusman

 

 
richhotrain
On the protptype, though, I have to believe that the Dash 8-40b runs faster than the RS-1.

 

Not necessarily.  B40-B's probably are geared and have their engines set to go about 70 max.  RS-1's that were equipped to haul passenger trains could hit 80-100 mph.

Its all about gearing.  A GP40 on a freight road can hit 70 max.  A F40 for a passenger line (same engine, trucks, etc) can hit 110 mph.

 

100 mph in an RS-1. Yeah, that sounds like fun.

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Posted by BRAKIE on Tuesday, March 15, 2016 7:35 AM

It wouldn't matter if either locomotive could run 200 mph since track speed and speed restrictions rules the speed of a train.

Every hear of a overspeed alerter?

Some older freight and passenger locomotives was equipped with goveners to prevent speeding.

Larry

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Summerset Ry.


"Stay Alert, Don't get hurt  Safety First!"

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Posted by charlie9 on Tuesday, March 15, 2016 3:03 PM

Yeah, Brakie.  On the IC our E units were geared for 117 MPH but by then the conductor was yanking on the signal line or even setting the air.  I only made a few student trips in passenger service but I think the conductor would usually crap out before the governor was tripped.  My favorite engineer used to say, "they bought a ticket-lets give 'em a ride".

Charlie

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Posted by wjstix on Wednesday, March 16, 2016 4:26 PM

BTW the RS-1 wasn't a yard switcher, it was a 'Road Switcher' - an engine that could run on the mainline or work in the yards. It was basically an "S" series switcher running on trucks designed for mainline rather than switcher trucks, with a section added behind the cab for a steam generator. RS-1s could be purchased with steam generators to be used in passenger service. I don't know the top speed, but I'd guess if a railroad had them geared for passenger service they could hit 60 mph or so, maybe more.

Stix
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Posted by 7j43k on Wednesday, March 16, 2016 5:52 PM

Alco said the top speed for their RS-1 with standard gearing was 60 mph.  GN said 65 mph for the same gearing.  It's possible there were other gearing options.

 

GN, by the way, did not put boilers in their RS-1's, so they were freight engines.  Except maybe on a branchline in the summer.  Maybe.

 

 

Ed

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Posted by BRAKIE on Wednesday, March 16, 2016 7:52 PM

charlie9

Yeah, Brakie.  On the IC our E units were geared for 117 MPH but by then the conductor was yanking on the signal line or even setting the air.  I only made a few student trips in passenger service but I think the conductor would usually crap out before the governor was tripped.  My favorite engineer used to say, "they bought a ticket-lets give 'em a ride".

Charlie

 

I forgot to mention "Tommy Overspeed" that hides in bushes with radar gun in hand and camcorder running. My understanding he looks for violaters running above the restricted speed limit in certain areas.

Example would be its 35 mph through Bucyrus,Ohio and a engineer pushes the limit to normal track of (say) 45 mph through town.

Larry

Conductor.

Summerset Ry.


"Stay Alert, Don't get hurt  Safety First!"

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Posted by wjstix on Tuesday, March 22, 2016 10:24 PM

This chart seems to be well-researched, and shows the 60 mph top speed. That wasn't blazing speed, but fast enough for many passenger trains. That being said, there weren't as far as I know a lot of passenger RS-1s, or any 'top of the line' trains that used them.

Interesting thing about Alco is they kept stuff in production. When EMD started the GP-9, they discontinued the GP-7. When Alco introducted the RS-2 and later RS-3, they kept making the RS-1...even after the RS-11 was introduced in the latter fifties. IIRC a railroad could buy a new RS-1 as late as 1960.

Stix
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Posted by WSOR 3801 on Thursday, March 31, 2016 12:41 AM

MILW used their RS-1s primarily as passenger train switchers in Chicago.  They had steam generators, and had water tenders built to allow switching a full shift on 1 refill.  One was set up with roller bearings to pull commuter trains, but that was a short lived assingment, and it went back to switching duties.  

The Dash 8 should move more cars at higher speed, and probably has a higher permissible speed before the overspeed trips.  I think ATSF used them for intermodal trains, maybe 70 mph or faster.  

ALCo also had 3 different engine families.  539 in the switchers and RS-1, 244 afetr the war, and 251 in the early 1950s, after the 244 was found to be lacking in durability.  

EMD kept with the same basic prime mover from 1939's 567 up to the 710, which ended production in the last year or two.  

Mike WSOR engineer | HO scale since 1988 | Visit our club www.WCGandyDancers.com

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