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100 wagon challenge





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#51 Il Grifone

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Posted 20 August 2017 - 08:22

The prototype certainly couldn't have managed much of a train around a three chain curve! (most locomotives couldn't go around it for a start).

 

The old Farish locomotives were quite powerful. I can remember being impressed by a Farish locomotive (a 'King' IIRC) pulling two of their Pullmans. My 'Duchess of Atholl' could just about manage one with a bit of a fuss. They did have traction tyres of course.


Edited by Il Grifone, 20 August 2017 - 13:30 .


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#52 locomad

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Posted 21 August 2017 - 01:14

The prototype certainly couldn't have managed much of a train around a three chain curve! (most locomotives couldn't go around it for a start).
 
.


Quite true, it was the curves which defeated us, I reckon 36" radius curves would have been ok.

There's mentioned in a few early 1960's RM's that quite a few modellers managed 100 wagon trains using pin point axles.

It's been fun trying it though lot learnt about types of model locos which have good haulage capacity quite a few surprises

#53 roythebus

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Posted 26 August 2017 - 18:53

Back in the 1960s when I had a Hornby Dublo Deltic, we tried an experiment at the Model Railway Club one night to see how much it would pull. the MRC test tracks haven't changed much since then dimensionally, only the track has changed since then, so anyone who knows the set-up will know the size of the track.

With the Dublo Deltic on the inner track we had a mixture of stock all the way round; a Triang Weltrol or similar spanned across to the middle track, where we had stock going right round again. I can't remember just how many wagons and coaches we had, but it was quite a lot and was reported in the MRC Bulletin at the time.

 

This of course was in the days before pin-point bearings were the norm, probably the only pin point stock was my Trix 5 car set and a few Trix plastic wagons, the rest were a mixture of Triang, Dublo and hand-built. The Deltic shifted them.

 

There was a bit of a cheat though, the MRC controllers at the time were found to give out about 18v DC! But the Deltic survived.



#54 Il Grifone

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Posted 27 August 2017 - 07:59

Most old controllers would give around 16-18 volts off load. The 12 volts was at rated current. A Dublo Deltic under load would draw a considerable current and pull it down nearer to 12. The sum of the source resistance and the track feeds would probably be a few ohms.

 

I don't know the layout involved, but as a rough estimate 3 wagons occupy about a foot of track and a dozen coaches about ten feet. 


Edited by Il Grifone, 27 August 2017 - 08:02 .


#55 Il Grifone

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Posted 27 August 2017 - 14:01

Here's a Dublo 8F half way there.  

 

She should be able to manage quite a few more (especially if the heavy die cast tender is replaced with something lighter).



#56 Golden Fleece 30

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Posted 27 August 2017 - 16:28

Those are not Dublo wagons though, modern pinpointed Mainline/Hornby/Bachmann etc so 51 of these should be easy lol.

Garry
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#57 Il Grifone

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Posted 27 August 2017 - 19:57

Hi Garry,

 

Yes they are all modern wagons with pin-point axles. 51 Dublo wagons would be a struggle even for a Dublo 8F, especially as this is the version with the ½" motor. The ringfield motor gives it a bit more T.E. (presumably due to the extra weight, as the locomotive slips well before stalling*?). Somewhere in the 'bible' there is a list of the expected loads up a 1 in 24 gradient (The Acho elevated sections). I think it is a bit optimistic however.

 

* or at least mine does!

 

David



#58 locomad

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Posted 28 August 2017 - 06:22

Hi Garry,
 
Yes they are all modern wagons with pin-point axles. 51 Dublo wagons would be a struggle even for a Dublo 8F, especially as this is the version with the ½" motor. The ringfield motor gives it a bit more T.E. (presumably due to the extra weight, as the locomotive slips well before stalling*?). Somewhere in the 'bible' there is a list of the expected loads up a 1 in 24 gradient (The Acho elevated sections). I think it is a bit optimistic however.
 
* or at least mine does!
 
David


This was one of the surprises discovered while messing about trying to find the best hauler, the 1/2 inch 8F can actually pull more than the ring field motor version, I suspect the ring field upsets the balance of the 8F so less weight on the front wheels causing slip.

As mentioned before my 1/2 inch 8F is a converted 2rail, one side steel wheels the other seems to have nickel silver, these wheels have more grip.

As for rolling resistance all stock is measured on my adjustable rolling road, just an adjustable incline, can select some HD stock to pass 1:40, have noticed that some pin point axles struggle with that, dirt, wear, wagon sides Wapping, etc can all take there toll over the years.

Pin point axle trains seems to greatly increased the rolling resistance on the curves, these does not effect as much non pin point.

Another factor I have noticed is momentum, heavy train has momentum, loco stalls or struggles on some section of track, the train itself pushes the loco over the rough section, trick of cause is getting the train going in the first place, great fun trying to drive the train, slight slip and reduce the power then apply slowly.

I think it is still possible, one or two very powerful locos, TH 9F, HD Co-Co, etc selected good running stock, 4foot curves even with non pin point axles

#59 roythebus

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Posted 28 August 2017 - 22:24

To answer Grifone, the layout is the MRC's test track which consist of something like a 6' straight section and semi-circles of about 4-5'radius each end; there's 3 circuits. It still exists in the same form today as when built in the late 1940s.

 

Pin point axles will give more friction on curves as the pin point tries to bore its way through the axle box journal. Also the friction on the inner end of the pin point will be far greater than on the outer end of the pin. :)  

 

The old MRC controllers were wired to give up to 24v dc as back in the 1940s some 00 stock used 24v! they were replaced some time in the 1970's to something more modern, like H&M duettes.


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#60 locomad

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Posted 06 September 2017 - 01:08

 
Pin point axles will give more friction on curves as the pin point tries to bore its way through the axle box journal. Also the friction on the inner end of the pin point will be far greater than on the outer end of the pin. :)  
 


I am beginning to think this challenge has opened up a lot more questions than answers, certainly learnt a lot over past two months, this might explain why older stock tends to decline in performance over the years basically pin point axles wear more.

The HD 2 rail axles also suffer wear while the metal 3 rail don't.

I've some 3 rail stock, locos and track so did over the weekend try some out on carpets, did notice that 3 rail locos can pull a lot more using 3 rail metal axles on the straights, however they did stuggle on smaller radius curves. I've future plans to lay a 3 rail layout in a shed where once a 2 rail layout once was, will certainly design in some larger radius curves using peco track an lay a 3rd rail in the centre.

Back to 2 rail and I'am very surprised in the difference between certain locos of the same type and class, adding extra weight, swopping motors, good overall service & clean etc I'am begining to develop a super class, certainly learning a lot
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