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Subroadbed, Roadbed and Track

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  • Let's see 20 puts me at 94 (maybe) 30, I don't think so. I have stopped jumping out of planes, so that should help.



    • You never know; A passenger terminal for which I built most of the track and turnouts is still in service at MIT's Tech Model RR club, 39 years later. My Rowley module will pass its 29th anniversary some time this coming winter.


      • I took some photos of some moderately complicated handlaid track in HO. I thought it might be useful to show how I break a job like this down into steps:

        I decided to start with the more sharply curved track through the diamond. I polished the weathering off the railhead to mark where to notch for points and clean the underside for frogs and guardrails.

        Here I'm laying the first rail for the rightmost turnout frog. Initially, I only drive enough spikes to hold the rail roughly in gauge, usually on alternate sides of the rail. When I need to, I can wiggle or snake the rail out for filing, cleaning, cutting etc.

        Here I've got two turnout frogs filed and located. To work on the leftmost (distant) turnout, I'm carrying its rails over the diamond's other track. I'm trying out Tim Warris' "notch the rails" approach for the first time. My previous diamonds have been built from many little bits of rail, with much filing.

        Turnout frogs located, one point notch still needs to be cut. Next will be the diamond's frogs. The T-pins are holding the 'flying' rails roughly in gauge.

        Once everything is located, I'll cut the two loose rails to length and insert the joiners (none of the rails have been permanently spiked or soldered to yet).

        I've learned that this is not a good example of workholding for applying a guardrail out-of-place. If I'm to try this again, the best idea I've had yet is to spike the rails down on a throwaway piece of Homasote.

        And here I've learned that rotary tool cutting disks are very much not a milling machine. It was way too easy to go too deep once I got through the head and into the web, and impossible to hold the tool well while my eyes were near track level. But almost all the awful is hidden by the solder I flowed in.

        Note that I didn't flow the solder in till I'd securely spiked all the rails involved on every tie, checking gauge and flangeway as I went.

        Flangeways have been cut with the rotary tool, now I'm trying to do a better job on the other 'top' rail's guard.

        The masking tape did a much better job of marking cut boundaries than the razor saw nicks I made on the first pair of frogs.

        Better than the first pair, but cutting disk followed by filing is still very much not a milling machine. And weights on an asbestos cement board aren't a purpose-built jig.

        Test fit reveals more filing is needed. Layout fluid (blue dye) would have showed the high points, but could I have gotten it out of the ties and ballast?

        Most of the hard work is done - filling in the closure rails and points of the turnout is routine, even if you've only worked with jig-built turnouts before. It will get a lot uglier when I cut the required gaps; While I can buy a .010 thick slitting saw, I would be weeks building the tool that could safely apply it to Code 70 rail in situ.

        My takeaway on Tim's 'notch the rails' method:

        1. A good deal less filing than 'many bits of rail', and no sore fingers from holding them while I file. And so, probably faster.

        2. Only one rail is noticeably out of position (RH rail of the sharply curved track, between its two frogs). And it isn't far enough out to bother .088 wheels. I'd have to fill the flangeway with solder and make it flange-bearing for Proto87, though.

        3. It is easy to create subassemblies with a 100W soldering gun that can only be taken apart with a torch. Luckily, that torch was 75 feet away and I hadn't built the subassembly into the layout yet. :erm:

        4. It is easy to over-notch with hand tools. Once you've done it, you either re-do the part or you hide it by flowing solder in.

        Notching the rails with hand tools is not precise enough for me (at least) to create the pretty reproduction of an antique bolted light duty diamond I was originally thinking of.
        Last edited by jbvb; 09-07-2021, 09:44 AM.


        • [:-dopey]JBVB, very nice presentation! Thanks for all the great photos and explicit explanation'..Nice work'.id="Comic Sans MS">



          • Very interesting, James. Thanks for posting all the details of your work on the crossing. I'm adding the "notch the rails" technique to my gotta try list.

            The sky is not my limit, it's my playground.


            • James,

              Thank you for the detailed how-to.


              Not everything that is faced can be changed, but nothing can be changed until it is faced. James Baldwin


              • In the past, I've posted pictures of the 'heel thrown point' turnout construction I'm using on my B&M Eastern Route. The turnout work shown above required two minor modifications to it:

                First, the fascia is low in this area because the edge of the layout is in the (model) Merrimack River. I handled this by using 2.75" point rods, only threading the lower .625" 3-48.

                Second, the simple form of the plexiglass coupler/insulator shown here only has one longitudinal hole. Normally, this places the block between the fascia and the slide switch. But here I had a choice: Thread several inches of the .0625" brass rod 1-72 vs. attach wood blocks to the bottom of the roadbed to support the DPDT switches.

                Extra threading seemed cleaner, but after turning the die more than 1,000 times to make all 3 rods, next time I'd order 1-72 threaded rod from Special Shapes instead.


                • My hand-throw handlaid turnouts all use a slide switch to change polarity to the points while locking them in one position or the other. I usually use DPDT instead of SPDT so contacts are available for signals. But sometimes I want more contacts:

                  I have quite a few 'swing blocks' on my layout (Paul Mallery called them 'X sections'). They're sections of track where the power comes from other tracks depending on turnout position. Here I'm doing this using a 3PDT slide switch. I'm using a Digi-Key SW-121-ND, which conveniently has the same mounting hole spacing as their SW-116-ND DPDT. The 3PDT is about 3/32" wider, which is easy to file out of my aluminum angle brackets.