I know how you feel Tim – years ago, when I first laid eyes on my Accucraft 1:20.3 #60, I was disturbed at the seeming narrowness of the tender cistern.
But see: Mulina, Tim, Colorado & Southern B-4C Class Locomotive #60, Quick Pic Book Series, BHI/Rail Systems, 2003, which depicts narrow tender cistern, at least as it would have looked in end times, when the C&S gave it to Idaho Springs.
I looked through my collection of vintage #60 photos and found little to prove the earlier-narrow-tender-cistern point one way or the other, except possibly this 1936 Otto Perry shot: http://digital.denverlibrary.org/cdm/singleitem/collection/p15330coll22/id/42512/rec/2
... which I had blown up, in pertinent part, so ...
The pile of cinders on the tender deck suggests narrow tender cistern to me, compatible with my own #60. I am at peace with my #60 tender, at least until someone here bursts my bubble …
Greetings, I have recently completed finishing my On3 PSC #60, despite being aware of issues regarding the tender frame. I've had this engine for a couple of years, and decided to go ahead and finish it, willing to revisit the tender frame sometime in the not too distant future. This week, I was prodded by a friend, who reminded me that the model was thought to have a tender deck that was 12" too wide.
I remembered this thread, and decided to go back and see if I could come up with anything to clarify the discussion, and decided to post the following.
I return occasionally to comments of days back in the 80's when Todd Hackett and I scrounged up information for Overland Model C&S projects, I believe the last one referenced #60's snowplow, which turned out to be the basis of the tall plows used on the Moguls.
The other link to the Moguls, which is very prominent on #60 is the tender cistern, which appears to be dimensionally identical to that from #6. I don't believe it was #6's cistern because I think this was used behind #60 during at least the later years of it's career as the Leadville switcher when #6 was still in service.
Regarding measurements provided above from Doug and the Schwedler guys from Coronado, both confirm that PSC got the cistern dimensions just right, at 6' wide, and 17' long. The Schwedlers have the width at 6' 2", and it may be at the rear or somewhere, but Doug is spot on with the water legs at 18" with a 36" bunker. At least this was the "targeted" intent. The Schwedlers have the C Channel sills at 6' wide and that is important as you will see shortly.
After reviewing photos from 1936, 1937, and 1940, it is clear that the decking was no wider than 6', as the 1X2 trim sat right under the sides of the cistern. We know that the decking and beams were recently replaced in Idaho Springs, and that is what has been measured here. But the original deck and sills were 6'.
With that in mind, the model's 7' 6" wide deck is actually 18" too wide from what it should be, but only 7" too wide based on what the measurements would be if the 1X2 trim was added to the ends of the decking present today. As the model was produced in 1981, it was obviously a simple mistake, like the square and only approximately placed hose reel cover on the cab roof. As they used to say in Vaudeville, "Well, that's just Show Biz!"
After checking a few things, including a pic sent by Keith, I now believe there is a very narrow ledge below the cistern, but certainly no more than a couple of inches at most, and that the decking was only replaced the one time, in the last few years. When we moved it in the mid 80's, there seems to have been considerable decay to the decking, but it seems to have been original to the 30's.
Also, I referenced the truck castings as being not very well done, but dang if they don't look a lot like #60's. The journal boxes are not as deep as other C&S tender castings, which makes me wonder if they were made this way because of the narrow sills. So PSC may have made this casting for #60. Another thing they got right is the overall frame length as provided by Doug Heitkamp. He said 248 1/2", and sure enough, PSC's total length including the beams is 20' 9". Close enough.
Final note, I've decided to go ahead and do this now. I'll post pics when it is done. It could be later this week.