Re: a second Caboose that Might Have Been.
Posted by John Greenly on Sep 15, 2017; 4:57am
URL: http://c-sng-discussion-forum.254.s1.nabble.com/the-caboose-that-never-was-tp8369p9417.html
Jim, that's a great caboose you're working on!
Well, of course Bill Uffelman had mine pegged: the photo of caboose 313 at the flood cleanup at Blackhawk. But I'm not going to number my model 313, and, at the risk of reopening a can of worms that has been analyzed closely already, I'm fascinated and befuddled by that photo. Here is the photo from Poole and Martin's NG Pict. VIII, the best reproduction of that image that I am able to make to show the undercarriage detail (no photoshopping at all, just good light and a camera taking a picture of the page):
and here is a version that has less shadow detail but shows a bit more of the righthand end of the caboose, from the Kindig et al Pictorial Supplement, p. 380:
(this is the first time I've posted images from books, please advise if this is not acceptable)
This photo has been discussed in detail, notably by Jim Courtney, in the Eight wheel caboose thread:
http://c-sng-discussion-forum.41377.n7.nabble.com/Eight-wheel-Caboose-on-C-amp-Sng-td488i80.html#a1933
Clearly, despite the addition of Westinghouse brakes, the undercarriage is not the modern version, and it is probably impossible to really figure out the details of what is under there with much confidence. But, as I was studying the image, all of a sudden I realized something that I don't think has been discussed, that really made my head spin. That is the apparent spacing of the wheels. I just could not make sense of where the wheels are under the car, compared with the 9 ft wheelbase that I believed the car to have. The wheelbase in the photo looks a lot shorter. To try to make sense of this, I've made a photo ("M") of my model, which does have a 9 ft wheelbase, from the same perspective, to compare with the second Blackhawk ("BH") image. Here it is:
I think I should explain how this was done. Mathematically, the perspective of a photo, that is, where the camera was located and how it was oriented, can be characterized exactly if you know the distances between four non-collinear points on an object in the image. So, for instance, a perspective view of a flat wall of a building can be corrected to a straight-on view if you know, for instance, the height and width of the building (the two bottom and two top corners of a rectangular surface), or the size of a window (again, four corners). In this case, I assumed that the car body dimensions in M and BH are the same.
Then all I have to do is make a photo in which the four corners of the car side are all at exactly the same points in the image M as they are in BH, and I'm guaranteed to have the same perspective view. It's quite fascinating to do this, because you discover that indeed there is exactly one unique relation of the camera to the object in all three dimensions that gives the correct positions of the four points. It's VERY sensitive to small changes in distance, height and horizontal locations. I did it by putting the BH photo on the screen of my ipad, and taping on strips of paper to coincide with the roof line and the bottom edge of the side, and then marking the corner locations on those strips. Then I aimed the camera at the model and moved it (including changing the focal length, to get the right field of view at the right distance, also a unique value) until my chosen lines coincided, and the corner positions matched. Photo M is the result. (the locomotive in M is there just for fun, it's not the right dimensions to match BH). Unfortunately I see from the preview that the two photos aren't displaying at exactly the same size as I insert them in this post (BH is larger). I'll try to figure that out and fix it, but you can check to see how they compare, just hold a straightedge on your screen along the roofline of BH and then scroll down to M and see if they are parallel, and the same with the bottom edge of the car side.
I think you will see that the positions of the wheels (look at where they bear on the railhead) are not the same in the two images. They are substantially closer together in BH than in M. Notice that the far wheel on the other side is not visible in BH, it is hidden by the right wheel on the near side. In M, on the other hand, that far wheel is clearly visible between the two wheels on the near side, because the wheels are further apart. In fact, a simple comparison with the 9 ft wheelbase in M gives that the wheelbase in BH of caboose 313 is about 6' 4"!
What is going on here? Am I somehow not seeing where the wheels are? I think the clearer version of BH from NG Pict VIII leaves no room for error: we are seeing the two wheels on the near side of the car, yes?
Am I losing my mind? Well... never mind, might be true, but irrespective of that, am I seeing this correctly? I am quite confident of the image perspective comparison, but maybe I'm just not seeing the actual wheels in the Blackhawk photo somehow? If, on the other hand, this is correct, then the original undercarriage must have been replaced with this weird thing, as an expedient for accomodating the new brakes…?
Anyway, since for sure my model caboose doesn't have the same undercarriage as 313, I'm numbering it 1010, and declaring it a second hypothetical version of my Caboose that Might Have Been, as it might have looked if it did later receive the modern undercarriage but not the body rebuild, between 1910 and 1915 when it was scrapped. If I'm right about this weird undercarriage, than maybe it would have been replaced later… I find it hard to imagine that the car could stay on the rails very well with a 6' 4" wheelbase!!
URL: http://c-sng-discussion-forum.254.s1.nabble.com/the-caboose-that-never-was-tp8369p9417.html
Jim, that's a great caboose you're working on!
Well, of course Bill Uffelman had mine pegged: the photo of caboose 313 at the flood cleanup at Blackhawk. But I'm not going to number my model 313, and, at the risk of reopening a can of worms that has been analyzed closely already, I'm fascinated and befuddled by that photo. Here is the photo from Poole and Martin's NG Pict. VIII, the best reproduction of that image that I am able to make to show the undercarriage detail (no photoshopping at all, just good light and a camera taking a picture of the page):
and here is a version that has less shadow detail but shows a bit more of the righthand end of the caboose, from the Kindig et al Pictorial Supplement, p. 380:
(this is the first time I've posted images from books, please advise if this is not acceptable)
This photo has been discussed in detail, notably by Jim Courtney, in the Eight wheel caboose thread:
http://c-sng-discussion-forum.41377.n7.nabble.com/Eight-wheel-Caboose-on-C-amp-Sng-td488i80.html#a1933
Clearly, despite the addition of Westinghouse brakes, the undercarriage is not the modern version, and it is probably impossible to really figure out the details of what is under there with much confidence. But, as I was studying the image, all of a sudden I realized something that I don't think has been discussed, that really made my head spin. That is the apparent spacing of the wheels. I just could not make sense of where the wheels are under the car, compared with the 9 ft wheelbase that I believed the car to have. The wheelbase in the photo looks a lot shorter. To try to make sense of this, I've made a photo ("M") of my model, which does have a 9 ft wheelbase, from the same perspective, to compare with the second Blackhawk ("BH") image. Here it is:
I think I should explain how this was done. Mathematically, the perspective of a photo, that is, where the camera was located and how it was oriented, can be characterized exactly if you know the distances between four non-collinear points on an object in the image. So, for instance, a perspective view of a flat wall of a building can be corrected to a straight-on view if you know, for instance, the height and width of the building (the two bottom and two top corners of a rectangular surface), or the size of a window (again, four corners). In this case, I assumed that the car body dimensions in M and BH are the same.
Then all I have to do is make a photo in which the four corners of the car side are all at exactly the same points in the image M as they are in BH, and I'm guaranteed to have the same perspective view. It's quite fascinating to do this, because you discover that indeed there is exactly one unique relation of the camera to the object in all three dimensions that gives the correct positions of the four points. It's VERY sensitive to small changes in distance, height and horizontal locations. I did it by putting the BH photo on the screen of my ipad, and taping on strips of paper to coincide with the roof line and the bottom edge of the side, and then marking the corner locations on those strips. Then I aimed the camera at the model and moved it (including changing the focal length, to get the right field of view at the right distance, also a unique value) until my chosen lines coincided, and the corner positions matched. Photo M is the result. (the locomotive in M is there just for fun, it's not the right dimensions to match BH). Unfortunately I see from the preview that the two photos aren't displaying at exactly the same size as I insert them in this post (BH is larger). I'll try to figure that out and fix it, but you can check to see how they compare, just hold a straightedge on your screen along the roofline of BH and then scroll down to M and see if they are parallel, and the same with the bottom edge of the car side.
I think you will see that the positions of the wheels (look at where they bear on the railhead) are not the same in the two images. They are substantially closer together in BH than in M. Notice that the far wheel on the other side is not visible in BH, it is hidden by the right wheel on the near side. In M, on the other hand, that far wheel is clearly visible between the two wheels on the near side, because the wheels are further apart. In fact, a simple comparison with the 9 ft wheelbase in M gives that the wheelbase in BH of caboose 313 is about 6' 4"!
What is going on here? Am I somehow not seeing where the wheels are? I think the clearer version of BH from NG Pict VIII leaves no room for error: we are seeing the two wheels on the near side of the car, yes?
Am I losing my mind? Well... never mind, might be true, but irrespective of that, am I seeing this correctly? I am quite confident of the image perspective comparison, but maybe I'm just not seeing the actual wheels in the Blackhawk photo somehow? If, on the other hand, this is correct, then the original undercarriage must have been replaced with this weird thing, as an expedient for accomodating the new brakes…?
Anyway, since for sure my model caboose doesn't have the same undercarriage as 313, I'm numbering it 1010, and declaring it a second hypothetical version of my Caboose that Might Have Been, as it might have looked if it did later receive the modern undercarriage but not the body rebuild, between 1910 and 1915 when it was scrapped. If I'm right about this weird undercarriage, than maybe it would have been replaced later… I find it hard to imagine that the car could stay on the rails very well with a 6' 4" wheelbase!!
John Greenly
Lansing, NY
Lansing, NY
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