Sow's Ear Part Six: Trackwork Travails.

The old layout is a mix of old Atlas brass sectional track, Atlas and AHM switch machines, and some even older legacy track in nickel silver from my wife's uncle Dick Fager who had a big layout back in the day. The bench is a single sheet of 4x8 plywood, cut with a sabre saw into the basic shape and screwed down onto a 1x4 frame. Roadbed is cork. It worked well enough when new, particularly on short trains and short engines. But if you introduce 6 wheel truck diesels and longer trains with longer cars, the fact that there are tight radius curves and inclines over most of the route, and turnouts immediately before and after curves, and on inclines can mean lots of frustration and frequent use of "the big hook".

A few assumptions, and guiding principles:

- Preserve the original 4x8 layout as much as possible, in track plan and structure, while updating its operation and appearance. This is a restomod, not a resto or a replacement. 

- Approach reliable full hands off operation,  upgrading and replacing components as necessary to achieve this.

A few repetitive improvements need to be made in many places. 

- ensure near perfect track section to section alignment, horizontally and vertically

- superelevate the outside of curves slightly to ensure wheels stay in, particulary near and in turnouts

- remove all flex from all track. If it can move, it will always move in a way that enables derailment. 

This is all probably obvious and natural to mature, experienced builders. It was not so for my teenage self ;-)

- If track is replaced, replace with nickel silver. I have to stick with Code 100 due to some legacy power, and to Atlas turnouts due to the constraints of the original design.

- All new components to be dcc compatible or dcc ready.

Here is a glimpse of the "before" from overhead:

It was a "cookie cutter" layout design from a Kalmbach plans book of the 70s. Here we have (nearly) all structures removed to allow for a deep vacuuming. You can also see a trace of the saw line from south to north through the left-of-center that allowed it to be moved to its current location. The scenery is largely tinted plaster over steel screen, draped over cardboard forms, decorated with colored "sawdust" and lichen bushes and trees. Before too much scenery improvement is made, all track must be mechanically and electrically sound. All fiber tie track will be replaced, and as much brass as necessary to ensure long term good operation. Sectional track will be replaced with continuous flax track, and where joints are needed, solder. All connectors and new rail will be code 100 NS. I intend to use all my legacy locomotives, so moving to code 83 is not possible due to wheel flange dimensions.

-Challenges-

1. There a few truly level spots. Almost the entire layout is curves on a grade. 

2. All mainline entrances and exits into turnouts are curves.

3. Many of my locomotives have 6 wheel trucks - SD-45, Alco PA, EMD E-3. These will be the most difficult to move flawlessly around the curves due to the side stresses on the wheel flanges on an 18 inch radius.

4. All legacy track is either brass sectional track, Atlas code 100, or even older nickel silver on fibre tie flex track.

5. Roadbed is cork over plywood. In many places, the track is canted outboard, the opposite of superelevated. 

6. In decades past, before new roof, soffit, and fascia were installed, the attic was visited by birds, whose discharge corroded some track.

-Process-

Run the long locos around, looking for mechanical (derailment) issues. Run shorty locos around looking for electrical issues.

Rather than a blow-by-blow, here are the patters of failures and the corrective actions taken.

Electrical - Eliminate brass sectional with Nickel silver track. Use only new NS joiners where needed, and solder all joints not leading into /out of turnouts. Replace track power feeders with heavier gauge wire.

Abrasively (bright boy) followed by chemically clean (acetone) all track until clean. If necessary, replace turnouts if good contact is not longer possible. Points, and the rivets holding them were problematic, particularly where rail had gone green from Avian Issues. 

Proceed one track block at a time, and test repeatedly.

Mechanical - Every switch and rail joint was witnessed in motion under bright light (you'll need a helper to drive while you watch) at close range, in both directions, repeatedly, to see where wheels leave the rails. This is tested with a single loco, working your way up to a full A-B-A lashup in the case of the PA, as they perform differently under load.

Critical improvement areas - 

1. Superelevation. Using a small level, ensure the outside rail is at least level, and if necessary, slightly superelevated on curves. Shim as needed.

2. Alignment - joints in track need to have the rails as close to absolutely parallel as can be achieved, else long trucks will hop over the misalignment under load. No rail end gaps. Use extra nails near joints, as stress from flex track can slowly moved it out of square.

3. Turnout points. File the points to a feather edge if needed. I have seen a wheel climb out an OOB turnout point like going up a stair step when under load.

4. No ballast until no problems. Once you have ~ repeatable flawless operation, ballast away (see below), not before, or your repair efforts will be 3x harder. It will lock in your success or failure in rock and glue ;-).