Large Scale Central

Turntable pit - ideas needed

Track and Trestles
#1

Well, inspired by the turntable that Richard Smith made, I decided to make one of my own. I used the EBT Orbisonia pit for design ideas, but made mine a tad smaller in height and width.

Mine is 3 feet in diameter and about 3" high. So, it scales to just about 60’ in length. Now, I’ve made the table itself and got a good start on the pit.

What I want now is to have the sides of the pit be sloped towards the center. The center, about 12" in diameter will be flat with some drain holes. Thus, the slope will start about 6" from the center and run to the edges where the rail is. I just can’t figure out the best way to do this. --I’ve thought about concrete (since that’s what many used), but I’m not sure how I’d pour a slope all the way around. --I could use styrene sheet, but that would be difficult to get smooth joints - and figuring the shape could be problematic as well. --I could use my ballast and build it up to the right shape and fix it in place. So, has anyone done anything similar? Any ideas?

#2

Welp…I’m using a plywood deck to surround mine…which will be painted a concrete color and then hidden under ballast anyways,But then again…my turntable is elevated 40" too…

#3

What some folks have done is to use an upside down plastic, round garbage can lid for the pit. Drill a hole in the center for drainage…

#4

My turntable will be a solid deck i.e. the pit will be completely covered. Since I built several of these in HOm I’ll use the same method enlarged for 2m and with non-corroding/non-rotting materials wherever possible.

All of the turntables on the prototype are/were built like that - solid deck - no fun clearing snow out of the pit. :wink:

#5

I like the idea of a garbage can lid… I wonder if it couldnt be used as a mold for concrete, to get a thin, 1/2" or so, base. Insert 1/4" hardware cloth when its poured…Hrm…

#6

Bruce,

You could build it out of fiberglass cloth and resin. You would build the mold much like you’ve done, maybe a shade bigger and then lay cloth and resin in to achieve the hardshell. 3 layers would achieve a thickness that would hold its shape and then maybe add some strength on the under side. 6 layers would be a totally independent structure that needed no support. Keep it painted to protect from the UV and you’ve got a basic boat.

#7
Bob McCown said:
I like the idea of a garbage can lid... I wonder if it couldnt be used as a mold for concrete, to get a thin, 1/2" or so, base. Insert 1/4" hardware cloth when its poured..Hrm...
A plastic can lid could be cut off the concrete quite easily if the mold release didn't work. Don't know how sturdy you could get a 1/2 inch of concrete to be, even reinforced.

Ric’s idea of laying up in fiberglass is cheap and easy. You will need professional mold release but the balance of the materials can be bought at any auto parts store or marina. I like the fiberglass mat for building up thickness quickly. Sandwich it between to layers of cloth and you have a very rigid structure.

JR

#8

It may take a large garbage can to get a lid big enough! Well, I guess I should have thought about this BEFORE I got this far. [:D] Anyway, thanks for all the ideas! On an easier note, I found this picture.

It sure looks like they just piled up some ballast, doesn’t it? I think I’ll go with that look.

#9

Hi Bruce - Here’s some detail if you like. For a larger image right click the picture and select Open Link in New Window. These pictures were taken in October 2006. The deck was rebuilt and the steel painted this spring. [url=jon.barnbeckplace.com/ebt-tt1-1024.jpg]

[/url] [url=jon.barnbeckplace.com/ebt-tt2-1024.jpg]

[/url] [url=jon.barnbeckplace.com/ebt-tt3-1024.jpg]

[/url] I counted the rivets, but I couldn’t find a paper to write the number on. JR

#10

Jon, Hey, very nice pics! Thanks! I didn’t know the builder’s plate was white lettering when I did mine…but it still looks kind of cool.