7 ¼ verses 7 ½ How did this happen?

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cp4449
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7.5 vs 7.25

Post by cp4449 » Tue Jun 17, 2008 12:34 am

If you really want me to, I could comb the LALS archives for the answer. Also Gordon Sherwood, aged 98, still driving his car to LALS every Sunday, still has his wits could help us.

Let me know.
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Dick_Morris
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Post by Dick_Morris » Tue Jun 17, 2008 12:46 am

The Railroad supply American was a copy of Dick Bagley’s Disney locomotive.
I have copies of the prints for both locomotives. If RRSC copied Disney's locomotive, it's a very loose copy. There are many differences between the two designs. I wouldn't discount cross-polination between the two designs, but from appearances they could also be different designers' interpretation of the same prototype.

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Post by LivingLegend » Tue Jun 17, 2008 1:48 am

LivingLegend wrote:.....When design work started on Disney's loco (early 1950's).....
Thinking about it, I screwed up the date(s) in my earlier reply.... The track at Carolwood was the one who's construction started sometime during the early 1950's..... First months of 1950? I believe the 173, itself, was started a year or so prior. Before the end of the 1940's.


Doug....

I don't know for sure, but I think Disney bought the English loco after the work on the 173 and the trackwork began. I could be wrong on that. As I recall, Disney bought it while on a trip to England on business. Could have been on a visit to B-L on a toy marketing deal.

Also, I believe the track around David Rose's house was 7.25 gauge. PennsyFan, if he reads this can reply and verify if it is/was or not. I think David only ran his English locos on it. David's 4-8-4 (which he coal fired) was 7.5 gauge. He stored, and ran, that engine at LALS.


Dick:

Eddie Sargent was the Disney draftsman/designer who drew the drawings for Disney's 173 from a set of the drawings for the full size, prototype loco.

The version of the story that I was told buy a person who was somewhat involved at the time, re: the RRSC 173, was that Chet (Peterson) approached Lillian Disney attempting to obtain permission to market a the Disney design loco. The family declined Chet's offer. Is that story is 100% accurite?.... Who knows? The two who would be able to tell us for sure, Chet and Lillian, are no longer with us. Still, (again, as I was told) Chet/RRSC used the Disney 173 as the basis for the RRSC 173....

Enough changes and varances made by RRSC to the Disney 173 design to avoid legal problems. (Theft of design, etc) Cylinders were slightly different. 1.5" bore as opposed to the Disney's 2.125". Boiler was a completely different design. the RRSC's 173's original brass tender tank was different from the Disney tender. Plus, other changes.

SRRL5 was working for Chet at RRSC in those days, maybe he can add more.


CP4449....

re: Gordon driving his car to LALS.... Is Gordon still driving his little red open top MG to the track or another car?

EDITED.....


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Chris Lesiak
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Re: 7 ¼ verses 7 ½ How did this happen?

Post by Chris Lesiak » Tue Jun 17, 2008 1:48 pm

Trainman4602 wrote:Why 7 ¼ I have no clue.
To make it easier to fit the cylinders between the frames. The exact scale gage for 1-1/2":1' scale would be 7-1/16", but it was rounded up to 7-1/4" to make more room for the cylinders that were more commonly between the frames of English locomotives in the early years.

I suspect that if this decision had been made when outside cylinders were the norm, the gage would have beed rounded down to 7" to make more room for the outside motion.

But this assumes rational thinking. Seems strange that most of the USA uses the even wider 7-1/2" gage when our cylinders were always outside the frame.

Chris

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Re: 7 ¼ verses 7 ½ How did this happen?

Post by Curtis_F » Tue Jun 17, 2008 2:39 pm

Harlock wrote:There's also another factor to consider - I think 7 1/2" gauge scales more correctly for 2 1/2" scaled 3 foot narrow gauge. (I did the math some months ago, have to find that scrap of paper)

So 7 1/4" gauge is most appropriate for 1 1/2" scale and 7 1/2" gauge is most appropriate for 2 1/2" scale, if you want to make the minimum amount of modifications from the prototype when scaling down.
Actually 7 1/4" would be better for 2.5" scale engines as well. Why? Flange width & Back-to-Back.


2.5" scale engines have smaller than scale flanges and wider than scale Back-to-Back in order to run through switchs built for 1.5" scale equipment. This means builders have to cheat on wheel width and/or frame width and/or cylinder spacing to build models.


2.5" Scale flanges should be about .24" wide, and IBLS "standard" is .156"

2.5" Scale back-to-back should be about 6.83" wide, and IBLS "standard" is 7.125" for 7.5" gauge & is 6.87" for 7.25" gauge.

And, really, if you're building a scale model to run on a specific gauge, Back-to-Back should be the scaling factor, not the track gauge. This minimises the number of cheats that have to be made.


$0.02

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Post by Curtis_F » Tue Jun 17, 2008 3:08 pm

Harlock wrote:I agree that 7.x gauge is a very poor choice for hauling the public. We're starting a museum locally and I won't put anything in smaller than 12" for public hauling.
--M
15" is called the "Minimum Gauge" for a reason.


I'm just say'n... 8)

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Re: 7 ¼ verses 7 ½ How did this happen?

Post by cbrew » Tue Jun 17, 2008 4:24 pm

Curtis_F wrote:
Harlock wrote:There's also another factor to consider - I think 7 1/2" gauge scales more correctly for 2 1/2" scaled 3 foot narrow gauge. (I did the math some months ago, have to find that scrap of paper)

So 7 1/4" gauge is most appropriate for 1 1/2" scale and 7 1/2" gauge is most appropriate for 2 1/2" scale, if you want to make the minimum amount of modifications from the prototype when scaling down.
Actually 7 1/4" would be better for 2.5" scale engines as well. Why? Flange width & Back-to-Back.


2.5" scale engines have smaller than scale flanges and wider than scale Back-to-Back in order to run through switchs built for 1.5" scale equipment. This means builders have to cheat on wheel width and/or frame width and/or cylinder spacing to build models.


2.5" Scale flanges should be about .24" wide, and IBLS "standard" is .156"

2.5" Scale back-to-back should be about 6.83" wide, and IBLS "standard" is 7.125" for 7.5" gauge & is 6.87" for 7.25" gauge.

And, really, if you're building a scale model to run on a specific gauge, Back-to-Back should be the scaling factor, not the track gauge. This minimises the number of cheats that have to be made.


$0.02

Curtis F.
Curtis
I believe you need to check your math,
the proper gauge would still be 7.5" gauge. but you would not use the "IBLS Standards" for switch frogs and graud rails. due to the thicker flanges

Chris
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bcody
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GAUGE SELECTION

Post by bcody » Tue Jun 17, 2008 4:26 pm

The 7.5" gauge for hauling the public may be too small but it is about the largest gauge that can be transported without too much effort or expense. I have a 14 foot covered trailer in which I carry my 4+4 beam steam engine, tender and propane car. I also have my GE DASH 9 diesel, riding car and combination car. Topping off the load are three 5' riding cars and a 5' gon. If I were trying to run 15" gauge I would never be able to put them in a 14' trailer . I will not even get into the question of weight. The total weight of my loaded trailer is about 6,000 pounds with 7.5" gauge equipment and I need a 3/4 ton truck to haul it, the truck weighs 7,000 empty. I drive a Dodge diesel so the mileage isn't that bad, 13 - 15 MPG depending on hills, wind and the speed I drive. On my last trip from from Salt Lake City (Farmington), UT to Reno, NV I was cruising at 75 MPH with a 20 MPH headwind, I got 13 MPG. That was an expensive trip but I felt it was worth it. The S&S Shortline Railroad is a fun track to run. You only go around once and you must enjoy yourself while you can. Bill

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RE: Changing Gage

Post by 10 Wheeler Rob » Tue Jun 17, 2008 4:52 pm

What a typical American response! One member sugested the north east change to the non world standartd becuse the rest of the country scred it up.

The problem is you can not just move a few wheels on an axle with the steam locomotives, like on cars and most desiles.

Why would not the resopnse have been when are us silly Americans going to comply with the a world standard for a change so everthing works everywhere!!!!!!!

I for one live in the north east, and am building in 7 1/4" gage to IBLS, I am also making the steam locomotive so I can regage it, if the time comes to 7 1/2".

So anyone know how 5" world standard became 4 3/4" in the US??

Rob

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Re: 7 ¼ verses 7 ½ How did this happen?

Post by Curtis_F » Tue Jun 17, 2008 5:03 pm

cbrew wrote: Curtis
I believe you need to check your math,
the proper gauge would still be 7.5" gauge. but you would not use the "IBLS Standards" for switch frogs and graud rails. due to the thicker flanges

Chris
Chris,

My response was written based on the existing state of tracks, gauges and scales.

If you want to talk about starting a whole new track & wheel standard then, Yes, 7.5" gauge is correct for 3' gauge models in 2.5" scale.


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Re: 7 ¼ verses 7 ½ How did this happen?

Post by cbrew » Tue Jun 17, 2008 5:34 pm

Curtis_F wrote:
cbrew wrote: Curtis
I believe you need to check your math,
the proper gauge would still be 7.5" gauge. but you would not use the "IBLS Standards" for switch frogs and graud rails. due to the thicker flanges

Chris
Chris,

My response was written based on the existing state of tracks, gauges and scales.

If you want to talk about starting a whole new track & wheel standard then, Yes, 7.5" gauge is correct for 3' gauge models in 2.5" scale.


Curtis F.
Curtis
here is the math that i used to base my statement on,



IBLS standard for 7.5 gauge

Track gauge = 7.5
Back to back = 7.125
Flange width = .156

7.125+0.156+0.156=7.437


True 2.5 inch Scale for 7.5 gauge

Track gauge = 7.5
Back to back = 6.83 based off your post
Flange width = .24 based off your post

6.83+0.24+0.24=7.31
As long as my math is correct, you would need the 7.5 gauge not 7.25
This will give you 0.19 “play” so you not riding on the fillets

Now im just a code jockey
but maybe i need to go back to school. :shock: :wink:
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bcody
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GAUGE CHANGE

Post by bcody » Tue Jun 17, 2008 5:45 pm

Rob: I'm the one who suggested that the equipment/tracks in the North East be changed to 7.5" gauge. I suggested that so the equipment from the North East could be used on 90+% of tracks that they are not able to run on with their present configuration. I for one don't think I would ever return to the North East to run so it doesn't matter to me, just trying to suggest a method where the train guys from the North East could run on tracks throughout the rest of the US and not be limited to a small portion of the available tracks. Why I suggested the equipment/tracks in the North East be changed? It is a question of numbers, change less than 10% of the tracks versis 90+%. Those of us with 7.5" gauge currently have 90+% percent of the total US tracks to run on and I don't see me headed to the North East to run, too costly from Nevada. Bill

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