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Slack action Was RE: [SergentEng] Where to purchase

John Hagen
 

Andy,

You are absolutely correct about how the prototype deals with slack action nowadays.

That said, I’d venture a guess you weren’t around when steam powered freights were still plying the mainlines.

With the advent of diesel power railroads discovered that heavy freights could be started from stop by stretching out all the slack and using the low speed power of the diesel electric system to get the train rolling.

Steam locomotives did not have such an advantage so, when trying to get a heavy train moving, the standard practice was to back against the train to get the maximum slack built up, open the sanders, and then start the loco as fast as possible. The idea was to build up enough momentum as the slack ran out that the loco, now on well sanded rails, could keep from stalling an impressive flurry of spinning drivers, valve motion and side rods along with a lots of noise, smoke and ciders.

Yes, it was hard on draw bars and was to avoided unless necessary but it could be great to watch, from either end. Of course the best view was to the locomotive end but if you were at the caboose end, often a half mile or so away, seeing the way the caboose would be “snapped” into action was also interesting but more frightening to see than fun. The crew had to have themselves well prepared for the shock they were about to receive. It looked brutal.

It did not totally end with diesels but, as engineers became more attuned to how different they were than steam for starting a train, it occurred less and less as time went on. It can still happen but with today’s motive power it is quite rare. Not to mention that watching the same action with diesel power is just not the same.

John Hagen

 

From: SergentEng@... [mailto:SergentEng@...]
Sent: Tuesday, September 19, 2017 11:30 PM
To: SergentEng@...
Subject: Re: [SergentEng] Where to purchase

 

 

Mike

The real RR cars have all kinds of slack action that has to be taken into account of in train handling or there are problems w/ broken knuckles & drawbars, etc. When the real trains leave from a dead stop they have to do it slowly to avoid break in twos. Of course most of us modelers don't run trains over 30 cars so slack doesn't present the same kinds of prototype problems as the real RRs have. Our biggest break in two problems come from bad track work which causes misaligned couplers. >}


Andy Jackson
Santa Fe Springs CA

 

 

 

Posted by: Andy Jackson <lajrmdlr@...>


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Mike Van Hove
 

Andy and John,
I agree that slack was/is a fact of life, but my point is that a (model) train moving at a constant speed, on level track, shouldn’t have the accordian effect.

With the KD Couplers, it’s often quite an effect, and the Sergents really don’t do that.  Or if they do, it’s barely noticeable.

Mike Van Hove


On Sep 20, 2017, at 7:32 AM, 'John Hagen' sprinthag@... [SergentEng] <SergentEng@...> wrote:


Andy,

You are absolutely correct about how the prototype deals with slack action nowadays. 

That said, I’d venture a guess you weren’t around when steam powered freights were still plying the mainlines.

With the advent of diesel power railroads discovered that heavy freights could be started from stop by stretching out all the slack and using the low speed power of the diesel electric system to get the train rolling.

Steam locomotives did not have such an advantage so, when trying to get a heavy train moving, the standard practice was to back against the train to get the maximum slack built up, open the sanders, and then start the loco as fast as possible. The idea was to build up enough momentum as the slack ran out that the loco, now on well sanded rails, could keep from stalling an impressive flurry of spinning drivers, valve motion and side rods along with a lots of noise, smoke and ciders.

Yes, it was hard on draw bars and was to avoided unless necessary but it could be great to watch, from either end. Of course the best view was to the locomotive end but if you were at the caboose end, often a half mile or so away, seeing the way the caboose would be “snapped” into action was also interesting but more frightening to see than fun. The crew had to have themselves well prepared for the shock they were about to receive. It looked brutal.

It did not totally end with diesels but, as engineers became more attuned to how different they were than steam for starting a train, it occurred less and less as time went on. It can still happen but with today’s motive power it is quite rare. Not to mention that watching the same action with diesel power is just not the same.

John Hagen

 

From: SergentEng@... [mailto:SergentEng@...] 
Sent: Tuesday, September 19, 2017 11:30 PM
To: SergentEng@...
Subject: Re: [SergentEng] Where to purchase

 

  

Mike

The real RR cars have all kinds of slack action that has to be taken into account of in train handling or there are problems w/ broken knuckles & drawbars, etc. When the real trains leave from a dead stop they have to do it slowly to avoid break in twos. Of course most of us modelers don't run trains over 30 cars so slack doesn't present the same kinds of prototype problems as the real RRs have. Our biggest break in two problems come from bad track work which causes misaligned couplers. >}


Andy Jackson
Santa Fe Springs CA

 

 

 

Posted by: Andy Jackson <lajrmdlr@...> 


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Jeff Young
 

This is also why I moved to Sergents.  They look better too, but it was the accordion effect that drove me to them.


On 20 Sep 2017, at 15:05, Mike Van Hove mvanhove@... [SergentEng] <SergentEng@...> wrote:

Andy and John,

I agree that slack was/is a fact of life, but my point is that a (model) train moving at a constant speed, on level track, shouldn’t have the accordian effect.

With the KD Couplers, it’s often quite an effect, and the Sergents really don’t do that.  Or if they do, it’s barely noticeable.

Mike Van Hove



Mike Van Hove
 

Andy,
I guess I never answered your question:
I think the only place you can buy Sergent Couplers is from Sergent, himself.

Maybe an email to him might shed some light on the various possibilities?

Mike Van Hove

On Sep 20, 2017, at 9:34 AM, Jeff Young jeff@... [SergentEng] <SergentEng@...> wrote:

This is also why I moved to Sergents.  They look better too, but it was the accordion effect that drove me to them.



On 20 Sep 2017, at 15:05, Mike Van Hove mvanhove@... [SergentEng] <SergentEng@...> wrote:

Andy and John,

I agree that slack was/is a fact of life, but my point is that a (model) train moving at a constant speed, on level track, shouldn’t have the accordian effect.

With the KD Couplers, it’s often quite an effect, and the Sergents really don’t do that.  Or if they do, it’s barely noticeable.

Mike Van Hove