I made a major mistake with my original layout design.
My problem turned out to be at the grade/radius transition. I had a turnout at the bottom of my 30" radius 3½% grade transition. All my locomotives would clear the turnout at a reduced speed.
When I built my layout back in 1990 I didn't want problems so it is bolted and double screwed with lots of Elmer's Carpenters glue. To make things even worse the problem area is in a mountain so removing the old track work is going to be a real undertaking.
My plan was to totally remove a 38" section of the 30" radius track and it's support structure then replace it with a new section. The new section will be built on ¼" thick plywood cut to fit the new 24" radius of the Atlas Flex Track and add a curved turnout to make a smooth transition curve to my siding. The turnout from the mainline into my station is the culprit, I will replace it with a new turnout as well as the following turnout into that selects one of my two station/yard tracks.
December 26
I'm going to build the support structure a bit different this time. I think I have come up with a better way to make grade transitions. This will be my first attempt using this type of construction.
The bottom portion of the drawing above shows the dimensions of an angled wedge cut from a 1" x 2" x 48" pine furring strip. That will keep the grade at precisely 2%. So that the board will bend to conform to the 24" radius I'll slot the inside edge with ½' deep vertical cuts with my table saw every 3" so that the board will bend easy. I will use ½" number 6 wood screws through the plywood into the furring strip to secure them together. If every thing works as planned I'll use some Elmer's Carpenters glue for added strength.
December 30
After I worked at removing the 25 year plus old track, roadbed and support structure I was almost totally done in for the day. That was a lot more work than I expected. The demolition took 4½ hours.
After cleanup the mainline down grade into the new curve wasn't exactly what I expected so that afternoon I removed the support columns leaving the ¼" x 4" plywood roadbed for the 60" down grade. I will replace the column type supports with a contoured 1" x 4".
I worked on my CAD for several hours and came up with a new grade profile shown in the drawing below. The contour ended up at 3/16" in 24".
Next is cutting out the new support from 1" x 6".
The new curved section is almost ready to be glued in place.
It lines up perfect with the mainline and the turnout into my yard and station.
New Years Day 2015
The above picture shows the finished track work. The track is Atlas Flex held down on to Midwest Cork Roadbed with track nails.
The picture above is a view looking up the grade to the tunnel portal. Looking at the drawing of my layout earlier in this post the red mainline is the outside track in the picture above, the green mainline is the inside track leading into the new curve.
Both of the mainline tracks are on a 3% grade and enter the tunnel portal at the same level then they split directions inside the tunnel. The outside track continues up at the 3% grade to the upper level and the inside track turns into a 3% down grade back to the lower level.
January 5
To test my new curve section I ran a complement of many types of locomotives. I ran my most touchy locomotives first. I have two Bowser GS4 mechanisms with Bachmann shells, they are super touchy because of their long driver wheelbase. They ran fine so that told me all three grade transitions were on the money. Next came my Rivarossi Articulateds and they had no problems either.
I spent over 8 hours running my entire locomotive fleet, some haven't been run for many years so it was an exciting day to see them in operation again.
Watching my 9 car Daylight Passenger pulled by two Athearn SD40-2 frames with Cary E7 shells running at a constant high speed without any problems is a first. At this point I declare my new transition/curve fix a success.
There was a second benefit of lengthening the siding 20".
My Christmas present to myself turned out to be more work than I anticipated but it fixed my problem curve so it was well worth it.
1 comment:
I'm impressed by your track troubleshooting and solution - "Not so simple, but well worth the results!".
I'm very impressed by your detailing of the history of your hobby - particularly the scratch-building of the houses.
Dave Clifford
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