Re: Determining car dimensions from photographs.
Schuyler Larrabee
One thing that goes along with Rob's methods is that at some point along the
side of the car, if you've got these different size wheels in the photo, the vertical dimensions of the image in the car will be "to scale." I'm not going to indulge in the math to figure this out, but if the inboard wheels are, say measuring with a scale rule one half inch off, one larger, one smaller, then the midpoint between the axles will give you a point at which the vertical dimensions are to scale. Realize, please, that I don't necessarily mean HO scale, but rather some other recognized scale, like 3/8" = 1'-0" or something. At that point you can use the scale that works to measure off directly. Another thing is that if you do have a square-on photo, and it's inconveniently not to scale, and you don't have a way to make it so, you can establish an angle along which you can measure to get the dimensions to read right. So if your photo measures 38' along the length, and you KNOW that the length should be 40'-6", then angle the scale you have so that the zero mark is at one end, and angle the scale so the 40'-6" mark is in line with the other end. You can then, carefully maintaining that angle, measure off dimensions that are parallel to the original length that you know for sure. As to finding drawings. A few of you know that I did drawings of the ERIE's 0-6-0 B5 and B5a steam switchers (LIST CONTENT!) which were published in the ELHS "The Diamond" magazine. I did those in CAD, many of the parts being drawn over scans of the drawings for the parts (drivers for instance) that I imported into AutoCAD, and then scaled to be the "right size." I started with a General Arrangement drawing from the NRHS group in Albany, that has the ALCO Historic Photos collection. Later I found that the California State RR Museum has the Lima Locomotive Works "Fire File," and I got MANY drawings from them. But not all that I really needed. Other drawings came to light in many different places, some by just talking to people who would say "Oh, I know someone who probably . . . ." and they would have something I wanted. One of the most difficult parts I was looking for was the tender tank. The frame I'd found, but the tank was a problem. One night, the email address for the curator for the Collection that is at a Texas University (SMU, I think) was in an email on this list. On a whim, I sent that curator an email inquiry. I am still somewhat amused that the reply came by snail mail, and she apologized that they only had one drawing. Aw, you guessed it! The tender tank! The point is that you have to be patient, and persistent and keep looking. It's out there, somewhere. Schuyler From: STMFC@yahoogroups.com [mailto:STMFC@yahoogroups.com] On Behalf Of Rob Kirkham Sent: Sunday, January 13, 2013 12:20 AM To: STMFC@yahoogroups.com Subject: Re: [STMFC] Determining car dimensions from photographs. I can't recall a particular article outlining the process of obtaining dimensions from a photo, but here is what I do: - start with photos that are as square to the object to be measured as possible (anything not at a 90 degree angle to the lens is going to involve more complex math - not my hobby) - find an object shown in the photo that has a known dimension - precisely measure its visible dimensions - so for example, imagine a broadside of a boxcar. Assume you know the wheel diameter is 33" When you measure the wheel diameter in the photo you find it is 1/4". - the ratio between the 33" wheel and its 1/4" size in the photo gives you a factor. - So (assuming everything else in the photo is to the same scale), a 1" long object in the photo is 132" long in real life; i.e. 33" divided by 1/4". - Looking at it another way, if 1" on the photo = 132 real inches, multiple any measurement on the photo by 132 to get the proto dimension. Most photos are not precisely square. Reality is that each 33" wheel on the real car may show in the photo as slightly larger or smaller than the others - so for example, one might be .235" diameter, another .24", the one you first measured .25" and the fourth .255". Each serves as the basis to convert other measurements on the drawing. so, for example, 1st wheel is .235" in the photo; that equals 33" in real life, so 1 inch on the photo is equal to 33" divided by .235, or 140.43; 2nd wheel is .24" in the photo; that equals 33" in real life, so 1 inch on the photo is equal to 33" divided by .24, or 137.5; 3rd wheel is .25" in the photo; that equals 33" in real life, so 1 inch on the photo is equal to 33" divided by .25, or 132; 4th wheel is .255" in the photo; that equals 33" in real life, so 1 inch on the photo is equal to 33" divided by .255, or 129.4; (Assuming I didn't create a typo) What you might deduce from the different wheel dimensions taken from the photo is that the factor based on a wheel that is closest to the feature you are measuring is going to provide a better basis for your conversion than a factor based on a wheel that is further away. For long measurements (e.g. side sill length), you might do well to average the factors converted for each wheel and use the average factor. When I scale a model from photos, I open an excel spread sheet and start to put in scale factors from known objects. I will then use each of those factors (in a separate column) to calculate dimensions for everything in the photo. Sometimes dimensions using one factor jump out at you. So the width of the side sill with each factor may come out at 9 3/8", 9 13/16", 10" and 10 7/16". I'd use the 10" dimension. Other times you have to make a best guess as none of the conversions results in a sensible dimension. Another tip - I import the drawing into a drawing program, enlarge it to 400% or more, and draw lines over top of the photo, following the shapes of the parts I am going to measure. My software includes a scale so I can measure the length of the lines I draw. By enlarging the photo, I draw more accurate lines and get more precise measurements off of it. At some point you'll also start to think about how many decimal places you care about. I always do over-kill and then round, but with a bit of thought I'm sure I could save myself the trouble. Rob Kirkham -------------------------------------------------- From: "Scott" repairman87@hotmail.com <mailto:repairman87%40hotmail.com> > Sent: Saturday, January 12, 2013 8:02 PM To: STMFC@yahoogroups.com <mailto:STMFC%40yahoogroups.com> > Subject: [STMFC] Determining car dimensions from photographs. Hello everybody hope your new year is going well.
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Re: Determining car dimensions from photographs.
Jack Burgess
Others have provided the general idea and it applies not only to freight
cars but buildings, etc. I wrote an article on developing plans from photos for the February 2012 issue of Model Railroad Hobbyist which is still available free online from their website. In the article, I start with a simple building (could be a freight car) and work from there. Another trick that I don't think anyone mentioned is board counting. If you know one dimension, such as wheel diameter, you can get the grab iron width and from that, the board width. With the board width, you can determine other things. Jack Burgess Newark, CA
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Re: Determining car dimensions from photographs.
Robert kirkham
I guess another observation is worth mentioning: I do the actual drawing in Google Sketchup. That allows me to create a 3 dimensional view, and rotate it to the same angle or view as any photo in my collection. And it will throw pseudo shadows on the part. What I have found is that by looking at a drawing from the perspective of the various photos I am working from, I will notice if some part isn't looking right. The software often provides the 3d perspective necessary to identify a measurement that is out of proportion to the rest. Of course it is only as good as your photos . . .
Rob -------------------------------------------------- From: "midrly" <midrly@yahoo.ca> Sent: Sunday, January 13, 2013 9:45 AM To: <STMFC@yahoogroups.com> Subject: [STMFC] Re: Determining car dimensions from photographs. The May, 1996 Railroad Model Craftsman has the article "Plans from pictures" by James Tangney, It's an essential read to understand the process, regardless of whether you are using a computer programme or manual methods. Not only does it cover the (easy) math involved, but also has some hints as to derive true dimensions from such things as shadowed rivets in photos. He uses track gauge and coupler height from rails as two standards from which to obtain relative measurements.
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Re: Determining car dimensions from photographs.
Charlie Vlk
There are also "proportional dividers" which can be set to automatically
convert a photo or drawing divider setting to a larger or smaller proportion corresponding setting. Finding such old school equipment may be a challenge. But with computers I have found that it is easier to use scanned in photos that can be adjusted (even some free drawing programs have perspective tools that can flatten an image) to use as a base layer over which you can draw in separate layers. Even if the photo is slightly in perspective you can count on one vertical strip to project vertical dimensions. Truck centers and other known horizontal dimensions can be used to landmark key elements. Charlie Vlk
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Re: Determining car dimensions from photographs.
midrly <midrly@...>
The May, 1996 Railroad Model Craftsman has the article "Plans from pictures" by James Tangney, It's an essential read to understand the process, regardless of whether you are using a computer programme or manual methods. Not only does it cover the (easy) math involved, but also has some hints as to derive true dimensions from such things as shadowed rivets in photos. He uses track gauge and coupler height from rails as two standards from which to obtain relative measurements.
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Steve Lucas.
--- In STMFC@yahoogroups.com, Nelson Moyer wrote:
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Re: USRA SS boxcars with composite ends & doors
midrly <midrly@...>
Rutland 7999 was a Canadian Government Railways/CN car that the Rutland recovered from Lake Champlain after paying for the "destroyed" car. It had a wood roof, not the Hutchins roof of the Accurail model. The most accurate model of this car was made by Dennis Storzek before he started Accurail. Here's the model--
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http://oldmodelkits.com/index.php?detail=23179&page=2&newlist=1 Steve Lucas.
--- In STMFC@yahoogroups.com, "Benjamin Scanlon" wrote:
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Re: Determining car dimensions from photographs.
Scott,
1) Get a pair of "drafting dividers" ... they are a high quality "compass" but both ends are metal points. Very good for transfering measurements - and you will find new ways to use them for a long time. 2) If you don't have one of the very affordable digital calipers get one. You want one that allows you to switch between metric and english at the push of a button (I haven't seen one that doesn't but it is a key feature). 3) If the picture(s) you are working from aren't fairly square you are going to have to carefully work everything out. However - it is rare these days to need to use photos for dimensional data ... for subjects in our interest range. If you have a pic and you want 'plans' for it ... usually it is as close as a Google search. Another great resource is "old hobby mags". A third way is to ask questions on this list ... often there is someone who has already done that car! Many kits include plans - if the car in question has ever been produced ... If you are working on a car that is earlier than about 1930 you are more likely to have to develop your own measurements ... - Jim P.S. I know, I know ... you already have a usable pic so why go do the research? You may find that when doing the research you will learn other stuff you didn't know and end up with a better model! Besides when doing the research you are likely to find your self "humming a happy tune" ...
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Re: Determining car dimensions from photographs.
Nelson Moyer <ku0a@...>
Rob's photo/line method is especially useful using Google SketchUp, which calculates length of lines in prospective drawings from a single known dimension. I used it to determine the dimensions of pin-connected through truss bridge from a three-quarter view photo using track gauge as the known dimension.
Nelson On Jan 12, 2013, at 9:19 PM, "Rob Kirkham" <rdkirkham@live.ca> wrote: I can't recall a particular article outlining the process of obtaining [Non-text portions of this message have been removed]
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Re: New Haven 38' gondolas
cinderandeight@...
Don,
If you want to buy resin coated paper locally I agree it is getting darn hard to find. I have a store 20 miles away that still carries paper and supplies. I usually have no problem getting it online from Valley Litho Supply at a reasonable price. Rich Burg
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Re: Resin tank car kits
Clark Propst
The only tank cars I will now consider buying are those that could have hauled Packing House Products PHP. Lard, tallow, etc. Mainly GATC cars. This SC&F kits I'm ready to decal is a plain 8K GATX 6 radial course car.
I have the SC&F 1638 for my only oil jobber, might be tempted to buy a new three dome for them too. Looks like I'll stay away from Sunshine. How about the newer F&C offerings? Clark Propst
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Re: Determining car dimensions from photographs.
Richard Brennan <brennan8@...>
The late Jim Tangney - MMR#65, had a handout describing the manual method... using drafting techniques.
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I'm not sure where my paper copy is... (box #n of many) The newer way is to use a software program: http://en.wikipedia.org/wiki/Photogrammetry -------------------- Richard Brennan - San Leandro CA --------------------
At 08:02 PM 1/12/2013, Scott wrote:
I saw in one of the historical society magazineshad an article on determining car dimensions from photographs.
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Re: Determining car dimensions from photographs.
Robert kirkham
I can't recall a particular article outlining the process of obtaining dimensions from a photo, but here is what I do:
- start with photos that are as square to the object to be measured as possible (anything not at a 90 degree angle to the lens is going to involve more complex math - not my hobby) - find an object shown in the photo that has a known dimension - precisely measure its visible dimensions - so for example, imagine a broadside of a boxcar. Assume you know the wheel diameter is 33" When you measure the wheel diameter in the photo you find it is 1/4". - the ratio between the 33" wheel and its 1/4" size in the photo gives you a factor. - So (assuming everything else in the photo is to the same scale), a 1" long object in the photo is 132" long in real life; i.e. 33" divided by 1/4". - Looking at it another way, if 1" on the photo = 132 real inches, multiple any measurement on the photo by 132 to get the proto dimension. Most photos are not precisely square. Reality is that each 33" wheel on the real car may show in the photo as slightly larger or smaller than the others - so for example, one might be .235" diameter, another .24", the one you first measured .25" and the fourth .255". Each serves as the basis to convert other measurements on the drawing. so, for example, 1st wheel is .235" in the photo; that equals 33" in real life, so 1 inch on the photo is equal to 33" divided by .235, or 140.43; 2nd wheel is .24" in the photo; that equals 33" in real life, so 1 inch on the photo is equal to 33" divided by .24, or 137.5; 3rd wheel is .25" in the photo; that equals 33" in real life, so 1 inch on the photo is equal to 33" divided by .25, or 132; 4th wheel is .255" in the photo; that equals 33" in real life, so 1 inch on the photo is equal to 33" divided by .255, or 129.4; (Assuming I didn't create a typo) What you might deduce from the different wheel dimensions taken from the photo is that the factor based on a wheel that is closest to the feature you are measuring is going to provide a better basis for your conversion than a factor based on a wheel that is further away. For long measurements (e.g. side sill length), you might do well to average the factors converted for each wheel and use the average factor. When I scale a model from photos, I open an excel spread sheet and start to put in scale factors from known objects. I will then use each of those factors (in a separate column) to calculate dimensions for everything in the photo. Sometimes dimensions using one factor jump out at you. So the width of the side sill with each factor may come out at 9 3/8", 9 13/16", 10" and 10 7/16". I'd use the 10" dimension. Other times you have to make a best guess as none of the conversions results in a sensible dimension. Another tip - I import the drawing into a drawing program, enlarge it to 400% or more, and draw lines over top of the photo, following the shapes of the parts I am going to measure. My software includes a scale so I can measure the length of the lines I draw. By enlarging the photo, I draw more accurate lines and get more precise measurements off of it. At some point you'll also start to think about how many decimal places you care about. I always do over-kill and then round, but with a bit of thought I'm sure I could save myself the trouble. Rob Kirkham -------------------------------------------------- From: "Scott" <repairman87@hotmail.com> Sent: Saturday, January 12, 2013 8:02 PM To: <STMFC@yahoogroups.com> Subject: [STMFC] Determining car dimensions from photographs. Hello everybody hope your new year is going well.
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Re: Determining car dimensions from photographs.
Bill Daniels <billinsf@...>
Damn...Algebra. Don't tell my wife...
Bill Daniels San Francisco, CA ________________________________ From: Bruce F. Smith <smithbf@auburn.edu> To: "STMFC@yahoogroups.com" <STMFC@yahoogroups.com> Sent: Saturday, January 12, 2013 9:14 PM Subject: RE: [STMFC] Determining car dimensions from photographs. Scott, I'm not sure what you're looking for, but the math is simple rations You need to divide the measure something on the photo by the known dimension of that item. That is then set equal to another measured item on the photo, divided by "X" (the real measure of the item) For example, if a 33" wheel measures 1" on the photo and the height of the carbody measures 10" on the photo, then 1"/33" = 10"/X Solve for X (cross multiply) and X = 330" Regards Bruce Smith Auburn, AL ________________________________________ From: STMFC@yahoogroups.com [STMFC@yahoogroups.com] on behalf of Scott [repairman87@hotmail.com] Sent: Saturday, January 12, 2013 10:02 PM To: STMFC@yahoogroups.com Subject: [STMFC] Determining car dimensions from photographs. Hello everybody hope your new year is going well. I saw in one of the historical society magazineshad an article on determining car dimensions from photographs. It included the various math needed to figure out sizes from photographs. I thought I had bookmarked it but I guess not. I understand I can get overall outside dimensions from the ORER but need to figure out all the detail stuff. Anybody remember seeing it or know the mathmatical equations to use? Thank you, Scott McDonald ------------------------------------ Yahoo! Groups Links http://docs.yahoo.com/info/terms/ [Non-text portions of this message have been removed]
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Re: Determining car dimensions from photographs.
Scott,
I'm not sure what you're looking for, but the math is simple rations You need to divide the measure something on the photo by the known dimension of that item. That is then set equal to another measured item on the photo, divided by "X" (the real measure of the item) For example, if a 33" wheel measures 1" on the photo and the height of the carbody measures 10" on the photo, then 1"/33" = 10"/X Solve for X (cross multiply) and X = 330" Regards Bruce Smith Auburn, AL ________________________________________ From: STMFC@yahoogroups.com [STMFC@yahoogroups.com] on behalf of Scott [repairman87@hotmail.com] Sent: Saturday, January 12, 2013 10:02 PM To: STMFC@yahoogroups.com Subject: [STMFC] Determining car dimensions from photographs. Hello everybody hope your new year is going well. I saw in one of the historical society magazineshad an article on determining car dimensions from photographs. It included the various math needed to figure out sizes from photographs. I thought I had bookmarked it but I guess not. I understand I can get overall outside dimensions from the ORER but need to figure out all the detail stuff. Anybody remember seeing it or know the mathmatical equations to use? Thank you, Scott McDonald ------------------------------------ Yahoo! Groups Links http://docs.yahoo.com/info/terms/
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Determining car dimensions from photographs.
Scott
Hello everybody hope your new year is going well.
I saw in one of the historical society magazineshad an article on determining car dimensions from photographs. It included the various math needed to figure out sizes from photographs. I thought I had bookmarked it but I guess not. I understand I can get overall outside dimensions from the ORER but need to figure out all the detail stuff. Anybody remember seeing it or know the mathmatical equations to use? Thank you, Scott McDonald
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Re: USRA SS boxcars with composite ends & doors
Benjamin Scanlon
--- In STMFC@yahoogroups.com, "Benjamin Scanlon" wrote:
(i should like to retract this as i believe from an article i have dug up that the accurail kit has Z and NOT L bracing. just to make that clear. especially to dennis s who i believe did the kit! ben)
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Re: USRA SS boxcars with composite ends & doors
Benjamin Scanlon
i now have the 'RailTT' boxcar which is apparently based on a canadian version of a USRA SS design car.
i have tried to upload a photo but it needs moderator approval and hasn't appeared,; if it does, it will be in an album called 'ben scanlon'. the finish on the TT car is sort of a random looking horizontal 'wood grain', rather than evenly slatted timbers. similar to this shot of an accurail model of the CN car that went to the rutland: http://www.steamerafreightcars.com/modeling/models/buchwald/r7999main.html is this finish typical on wood sheathed boxcars? it does look a touch unusual ... to me at least. i suspect the TT car may be inspired by the accurail one in some respects. the TT car comes with 'L' bracing rather than the 'hat section' bracing described as being standard for USRA cars or the 'Z' bracing used on later cars developed from the design. these are the only types of bracing i've seen mentioned for these cars, but would L bracing be appropriate? the accurail car appears to have L bracing. also the railTT car has ten fairly beefy ribs on the roof with dimpled ends, and single very thin ribs between each larger one. was this typical of the canadian cars, or other USRA cars? the accurail car appears to have somewhat finer ribs from the shot above. sorry for all the questions, but i'm trying to get an idea of what i can use, or adapt, the car for. regards ben
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Decker lettering
Everyone, Clover House has produced new Dry Transfer Lettering for Decker
reefers. (Decker & Sons meat packing plant of Mason City IA). This is for the 4th and final lettering scheme, used on 36' wood Decker reefers from 1935-1941/2. An image is visible on their website. The Transfers are available in O S HO & N. Clover House also offers lettering for the 2nd lettering scheme used by Deckers, the Iowana scheme. I believe Deckers was the largest shipper on the M&StL so these Dry Transfers could be of interest to a number of folks. Contact them at: Clover House PO Box 215 Veradale WA 99037-0215 tom@cloverhouse.com http://cloverhouse.com/Store/ Doug Harding www.iowacentralrr.org
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Re: Resin tank car kits
Bill Welch
I have built two of Sunshine's 8K insulated AC&F Type 27 tank cars, Warren and Cities Service. I did find myself re-engineering as I went. A BIG frustration was no guidance about how to figure out the location of centerline of the bottom of the car (to sort locating it squarely on the u/f) and the top of the car (to sort out positioning the tank's dome). This turned out to be one of those pesky problem solving opportunities that when I did figure it out I went around for a week patting myself on the back and saying I can build anything. A biggy for me was figuring our how to draw a straight line along a cylinder!
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One thing I sorted out in building these two, about two years apart, was that using long screws to secure the tank as well as the trucks makes perfect sense and I now build all my tank cars, styrene and resin, with long truck screws. doing this creates a sounder attachment for the tank to the underframe but also allow one to leave attaching the tank as one of the last steps, while allowing one to constantly have the tank on or off the underframe while building the model. I have ready to paint Sunshine's Type 30 General American. This has been a wrestling match and I finally sorted out that I needed to shortened all for of the Bolster parts to get the one-piece running board to sit correctly and squarely on the u/f. In the process I decided to convert it to a car for Union Starch and have gone overboard adding bits and pieces. I have built two of Sunshines UTLX X-3s with three more to build and two X-5s. These are time consuming because of the many steps and care required but are beautiful models. SC&F kits are well engineered. I have his first five kits all at the stage where the tank is secured to the u/f with long screws and the running board systems for all five has been dry fit. But Jon does not include a line scored on the bottom sheet indicating where the centerline is, again leaving this up to the modeler. Very frustrating. I purchased Jon's two new kits here at Cocoa Beach (and two for Dan Smith), and he is sold out for now. I find building tank cars, whether they are styrene or resin, time consuming, an invitation to re-engineer/add little details and rewarding. Bill Welch
--- In STMFC@yahoogroups.com, wrote:
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New file uploaded to STMFC
Dave Sarther
Bruce,
Thanks for sharing this information about weathering on-line for those who are unable to attend the meet in Cocoa Beach. Dave S. Tucson, AZ
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