History behind scale formats?

[scubaed1911]

Is there some history behind the seemingly standard of scale boats?

1/72, 1/48. Why 1/32; was 1/30 not specific enough?

I don't usually have minutia running thru my mind at night, but this captured my attention.

What's the rationale?

Thanks in advance!

Ed

[He Who Shall Not Be Named]

I'll take a stab at this.

The 'nautical scales' of 1/192 (1/16" = 1'), 1/96 (1/8" =1'), 1/48 (1/4" = 1'; quarter-scale; admiralty scale), 1/24 (1/2" = 1'), and 1/12 (1" = 1'; doll-scale) are halves of one another and likely founded on the imperial measurement system (inches and feet). Every 'booklet of general plans', BuShips/NavSea publication are almost always in 1/96 scale.

But, before I blather on and make a complete fool of myself, I'll defer to Jim Christly, the most knowledgeable living guy on this and other related subjects. I'll bounce this very good question off him and hopefully we'll all come away much better informed as to the origins of the various scales we model-builders work to today.

David

[He Who Shall Not Be Named]

First. This guy, Jim Christley: https://fineartamerica.com/profiles/...tley?tab=about He's done quality time under and above the water. Even today he employs water to suspend his pigments.

His credentials are, in my book, SOLID! The most trusted historian I've ever had the pleasure of knowing (and I've rubbed shoulders with a few).

And now, with his permission, I copy his input on the subject of 'scale'.

Here is my understanding of the subject. With the introduction of interchangeable parts for machinery in the early 19^th century came a need for a 'language' that would enable a machine shop at “A” describe a part to a machine shop at “B”. The language was the engineering drawing. A part of that drawing was the 'scale' that showed how large the part(s) were. The drawings themselves had to be 'standardized' so draftsmen could create drawings that were of a common size and used a common method of portraying part sizes. To make reliable drawings the draftsmen used rulers that were common throughout the drafting shop.

Because of the need to portray a large object on a smaller piece of drawing paper the drawings were made in a ratio of 'drawing size' to 'world size' called the 'scale'. A ruler with the proper ratio was used by the draftsman to create the drawing in the proper scale. These morphed into the familiar ones with a triangular cross section that us old folks remember fondly. These, called scales, were of two types. The first was in English measure and had eleven rulers divided off into fractions that could be related to actual sizes in various ways. On mine these are 16 (meaning the ruled lines were in 16ths of an inch), 3, 1, 1 ½, ½, ¼, 1/8, 3/8, ¾, 3/16, 3/32. The other type scale rule was in tenths (meaning it can easily be used for metric measures). This had scales of 10, 20, 30, 40, 50 and 60. These triangular 'drafting scales' relieved the drafting table of the need to have 17 separate rulers kicking around in the tools drawer.

With these common rulers in use and themselves being standardized a large drafting shop could have many draftsmen working on multiple drawings all using a common language of size. Often a shop used a common size for all their drawings. When various governmental agencies of different countries turned to civilian (not government shipbuilders) to build their navy's ships they had to specify what size the drawings were to be and what scales were to be used. The US Navy specified what size the drawings for various functions were to be. These specifications were used by professional ship model builders as well. For example the large ship model builder Gibs and Cox in New York built nearly all their ships in ¼ inch = 1 foot scale. During the uptic in ship construction prior to WWII the US Navy wrote specifications for drawings that had to be created. These specifications were a part of the contract arrangements with each shipyard, supplier and vendor.

As we moved from paper drawings and blueprints to computer generated drawings the drafting table, and their rulers went the way of the way of the lofting floor and the slide rule. Now the computer programs have as part of their menu the drawing size setup which has a number of scale ratios available as well as the 'custom' item which allows the user to set the scale ratio.

As the model building hobby took off there were a group of standard scale ratios. Model railroading has G or garden scale, O-guage (1/4” = 1') and “half O” or HO which for some reason is 1/87” - 1'. Model ship builders use scales that reflect the size of their kitchen table or basement shop or how well they can see (1/1200 and 1/2400 scale). Different companies used scales which reflect their respective markets. Sometimes these are not common from one model to the next. A case in point was Revell which used a scale such that the model's largest parts (flight decks, hull and so on) fit in a common box size.

The above is from the fading memory of an old guy who lived through the transition from 'box size scale' and Coker Craft parts through to today's 1/350 and 1/700 size international scales and photo etched parts. I still have my standard text on mechanical drawing (French's), drafting pens, scales and last but not least my father's and my slide rules. I use them to create 'eye rolls' from my grandsons. This explanation is sure to cause 'eye rolls' from the young 'whippersnappers' who read the whole thing.

Jim

Jim has, through the decades, published several books of his own as well as having contributed to the outstanding Norman Friedman Submarine Books. Here are some outfits that sell Jim's works:

https://www.bing.com/shop?q=jim+christley+books&FORM=SHOPPA&originIGUID=93D7946A27334C2AAF44E8520210790B

https://ospreypublishing.com/jim-christley

https://www.amazon.com/Jim-Christley/s?k=Jim+Christley

https://www.goodreads.com/author/show/334736.Jim_Christley

David

[roedj]

Merriman wrote:
Model railroading has G or garden scale, O-guage (1/4” = 1') and “half O” or HO which for some reason is 1/87” - 1'.

I hate to be 'that' guy but here's the actual skinny on these two scales - not that it matters much to nautical types.

1) The "G" in LGB or garden scale comes from the German word GROSS meaning large. LGB being Lehman Gross Bahn.

2) 'O' scale or more correctly "ZERO' scale was originally specified as 7mm = 1 foot (Leave it to the English to use a mixed scale like that) which figures out to about 1:43.5. The Continental types - mainly the Germans - said, "That's not close enough for the track used. We want the scale to be 1:45." When the scale came to America - mainly due to Lionel - the thinking was that there's no way the Americans are ever going to understand - 7mm=1 foot - so they went for the closest scale in Imperial measure which was 1/4inch = 1 foot or 1:48.

When smaller scales got started the first thought was lets make it one-half of 'O' scale - so 3.5mm = 1 foot - which today is called HO (half 'O') and figures out to be about 1:87.1 I have a German Type II sub in HO which - someday- will get used on one of our European modules for our modular European train layout.

I apologize for being 'that' guy.

Captain Crabby

[He Who Shall Not Be Named]

Merriman wrote:
Model railroading has G or garden scale, O-guage (1/4” = 1') and “half O” or HO which for some reason is 1/87” - 1'.

I hate to be 'that' guy but here's the actual skinny on these two scales - not that it matters much to nautical types.

1) The "G" in LGB or garden scale comes from the German word GROSS meaning large. LGB being Lehman Gross Bahn.

2) 'O' scale or more correctly "ZERO' scale was originally specified as 7mm = 1 foot (Leave it to the English to use a mixed scale like that) which figures out to about 1:43.5. The Continental types - mainly the Germans - said, "That's not close enough for the track used. We want the scale to be 1:45." When the scale came to America - mainly due to Lionel - the thinking was that there's no way the Americans are ever going to understand - 7mm=1 foot - so they went for the closest scale in Imperial measure which was 1/4inch = 1 foot or 1:48.

When smaller scales got started the first thought was lets make it one-half of 'O' scale - so 3.5mm = 1 foot - which today is called HO (half 'O') and figures out to be about 1:87.1 I have a German Type II sub in HO which - someday- will get used on one of our European modules for our modular European train layout.

I apologize for being 'that' guy.

Captain Crabby

Honest to god correction-amplification-addition to any topic of interest is most welcome here. You add to the knowledge base -- always a good thing. The O and HO scales have always been a mystery to me. Now I have a foundation as to the reason why. Good stuff, sir.

Great topic. May Revell rot in hell for their pragmatic approach to scale 'selection'.

David
Student

[trout]

I hate to be that 'THAT' guy.....but your math was slightly off.

Merriman wrote:
Model railroading has G or garden scale, O-guage (1/4” = 1') and “half O” or HO which for some reason is 1/87” - 1'.


2) 'O' scale or more correctly "ZERO' scale was originally specified as 7mm = 1 foot (Leave it to the English to use a mixed scale like that) which figures out to about 1:43.5.

When smaller scales got started the first thought was lets make it one-half of 'O' scale - so 3.5mm = 1 foot - which today is called HO (half 'O') and figures out to be about 1:87.1

1:43.5 = to HO is 1:87 (drop the .1)
Thank you everyone for the explanation! I learned a lot.

[He Who Shall Not Be Named]

what a bunch of anal-retentive ****s we are!!!!!!

[He Who Shall Not Be Named]

And I just got this invite from Jim:

I forgot to mention but if anyone wants to discuss the scale thing further or calls into question my profound and obviously entirely genius answer it is ok to publish my email oldsubs@hotmail.com.
Jim

[trout]

what a bunch of anal-retentive ****s we are!!!!!!

It's me, I resemble that remark.
I have copied and pasted this information so I can recall it later. Seriously good information!

[roedj]

I hate to be that 'THAT' guy.....but your math was slightly off.



1:43.5 = to HO is 1:87 (drop the .1)
Thank you everyone for the explanation! I learned a lot.

OK - I'll be 'that' guy once again:

My math is correct because the scales of 'O' and HO are not based on ratios like 1:43.5 or 1:87.1 but are based on the definitions - mixed Imperial with Metric.
1) "O" scale is 7mm - 1 foot (Original English definition - the Germans wanted a more accurate ratio for the 32mm wide track used or 1:45 - no other definition)
2) Thus HO- or one half 'O' -was defined as 3.5mm = 1 foot (which just happens to work out to 1:87.1.

Captain Correcting

[He Who Shall Not Be Named]

… and the gloves are tossed to the ice!

"DING!!!!"

[scubaed1911]

Thanks! You guys are amazing, and thanks for all the replies. Interesting and informative.

Ed

[trout]

I am persisting on this because maybe I am missing something......normally I would just walk away and make some remark like "New math", but I may be missing something.......
1/43.5 x 1/2 or the denominator times 2 or 43.5 x 2 or

43.5 + 43.5

43.5
43.5 +
--------

.5 + .5 is carried over to the ones column

01
43
43 +
-------

We add the ones column 1+3+3 = 7 (no carry over)
We add the tens column 4+4 = 8

I get 87

or 1/87

Captain, where is your .1 coming from? Is it a rounded up number from the 43.5 (like 43.53)?

Peace,
Tom

[roedj]

I am persisting on this because maybe I am missing something......normally I would just walk away and make some remark like "New math", but I may be missing something.......
1/43.5 x 1/2 or the denominator times 2 or 43.5 x 2 or

43.5 + 43.5

43.5
43.5 +
--------

.5 + .5 is carried over to the ones column

01
43
43 +
-------

We add the ones column 1+3+3 = 7 (no carry over)
We add the tens column 4+4 = 8

I get 87

or 1/87

Captain, where is your .1 coming from? Is it a rounded up number from the 43.5 (like 43.53)?

Peace,
Tom

Your mistake, Sir, is in thinking that the scales are defined by a ratio like 1:43.5 or 1:87.1. They are not.

1) 'O' scale (in the UK( is/was defined by this formula --> 7mm = 1 foot. If we scale that up to the prototype we get (12 inches times 25.4 mm/inch) divided by 7mm = 43.5429 - let's call it 43.5 which is close enough. Now you know the scale ratio but you would never build to that measure - you would use 7mm - 1 foot for precise modelling. All of this is designed to run on 32mm track. If we use 7mm - 1 foot as our guide the models are just a tad too big for the 32mm track to represent prototypical Standard Gauge track which is 56.5 inches or 1435 mm.

The Germans said, "Nein, es ist nicht gut genug." We want a true scale to build so they did some calculations and for 32 mm track to represent 56.5 inches the scale ratio has to be 1:45 with no mention of any 7mm = 1 foot nonsense..

So UK uses 7mm = 1 foot which is approximately 1:43.5 approximately. Did II mention that 1:43.5 is only an approximation. The Germans (and most of Europe) use a ratio 1:45 which is much more accurate.

2) So HO or one half of 'O' is defined as 3.5mm - 1 foot. That's it - no other definition. If we do the math we get (12 inches times 25.4 mm/inch) divided by 3.5 mm we get 87.08 - let's call it 87.1 for s**ts and giggles. Again it's just an approximation.

Captain Concerned

[trout]

Captain C,
Thank you! That makes sense for this old. I appreciate your extra explanation.!
Peace,
Tom