Sheepscot Turntable - Official Work Thread

[Gordon Cook]

Wayne, it's way more fun when we remember things the way they should have been instead of the way they actually were.

[Stephen Piwowarski]

It has occurred to me that because of the importance of the center bearing and inner ring in carrying the load, this design must have a pretty beefy foundation under those two components.
That being said, I am curious about the calculations regarding dynamic and static load, soil type, and moisture content. I don't even know if all of those things figure in to the design process, but I am interested in knowing how you decide how big/deep the foundation must be to adequately support the load.

Steve

[Mark Spremulli]

Been following this topic since its inception. I have one question about the table. What will the purpose be in regular operations besides just turning the locomotives to go into the future roundhouse. Has anyone worked out what the turntable's roll would be?

[Ken Fleming]

One thing about the turntable is that if its long enough to turn the rolling stock for even weathering.  Of course turning engines for different views works also.

[Rick Rowlands]

Do you know what the load bearing capacity of the soil is at the turntable location?  When we built our museum building here in Ohio we had a drill rig come out to take core samples, but if you just estimate the bearing capacity based upon the soil type that you have and build a large spread footing then you shouldn't have any problems.   Unless you are blessed with bedrock near the surface to build off of.

[Bill Fortier]

Going by the data on this site and the size of the ring rail, some back-of-the-envelope figuring comes up with a bearing capacity in the low-rent neighborhood of 150-170 tons. That's assuming a one-piece slab accommodating the center pivot and ring rail. Seems more than adequate.

[Wayne Laepple]

I noticed in the picture posted on Facebook today that the ring rail at Wiscasset did not circle the entire turntable pit.

[Harold Downey]

And if you look closely, you can also make out the lantern hooks on each end - near side on the near end and far side on the far end.

[Wayne Laepple]

Yes, and I believe I can see the turning pole on this end, right at the very bottom of the photo. And is that it on the other end, that skinny white thing I see?

[Philip Marshall]

I see the lantern hooks but I don't see a turning pole. Where exactly do you mean, Wayne?

There are a lot of other interesting non-turntable details in the picture as well: the cab roof of a Portland Forney hiding behind boxcar 561, the wooden-railed handcar jigger track and what looks like the bed of a milling machine (with two men sitting on it?) in front of the combine, and the rarely photographed caboose 301.

[Mike Fox]

Steve P., the soil that far down is going to be virgin blue clay. Very solid stuff

[Harold Downey]

I don't see the turning poles either.  The socket on the near end would be just out of the photo. You can see the track lock mechanism on this end -- a bar that is flipped back in the unlocked position in the photo.

[Wayne Laepple]

Well, I guess I was seeing things, or seeing something and reaching the wrong conclusion. I seem to do a lot of that these days. Anyway, right at the very bottom of the photo, if you drop straight down from the number 501 on the boxcar, I see a slightly angled object that I apparently mistook for the turning pole.

[john d Stone]

Right behind Waldo

[Joe Fox]

For what its worth, I think its best to replicate the roundhouse and table, to the best of our ability, build both structures like the prototype. A solid pit all the way around like the original would be very nice for 2 reasons, its makes the entire ring solid, and because the roundhouse and table will be the focal point of hundreds of pictures and it would follow better follow the museums historic goal.