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NUMBER TWENTY NINE

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Turnout Construction
Part 1 of 2

By Carl Baskin (ccvstmrearthlink.net)
Illinois Live Steamers
7.5” Track Committee Chairmen

(reprinted by permission from the ILS web site)

Introduction: Perhaps the title would be better served if it read instead…”Turnout Assembly”. This article describes how the ILS (Illinois Live Steamers) “assemble” a turnout on a table jig and not how to “design” the turnout. Two “well coordinated” members, can assemble a complete 7.5” gauge, #8.5 turnout in as little as 2 hours. ASSEMBLY time does NOT include the several hours of PREPARATION time needed to cut ties and machine the various parts, points and frog castings. Don’t let that scare you from building turnouts. Sooner or later, you’re going to want some switching choices on your own railroad. For efficiency sake, once machines are set up for a particular operation, several sets of parts are prepared at a time. The ILS usually keeps machined parts “in stock”.

Criteria: A considerable amount of time went into advance planning for designing and building turnouts. Guidelines were first established regarding the turnout design. Turnout design evolved with improvements made regarding the use materials where possible, simplify machine set up and lastly, simplify assembly. Various considerations have trade-offs. As such, the ground rules established for the ILS 7.5” turnouts were as follows:

  1. Turnout design will make use of standardized parts

  2. Material waste should be minimized

  3. Quick assembly requiring few special tools

  4. Functionality will take precedence over appearance and finally (but most importantly…)

  5. Turnouts must be reliable AND require little or no maintenance while eliminating lubrication!

Readers will note there has been no mention of cost, yet. While the club tries to minimize the cost of each turnout, cost was one of the previously mentioned trade-offs. Assuming all materials had to be purchased outright, a complete turnout (including switch throw mechanism) would probably cost in the $150-175 range. Members are extremely resourceful when the call goes out for supplies. Much of the materials used to fabricate turnouts came out of home/work shops as a donation as long as material sizes were acceptable. As a result of volume purchases, discounted materials and donations, the actual cost of the turnouts to the ILS has been much less.

Pre-Machined Parts: Starting with parts preparation, photos 10 and 11 show a machined frog (ILS pattern for mainline frogs are #8.5). The casting draft has been cleaned off where the closure rails and heel extension rails will be attached. The pattern for these frogs was redesigned to provide a heavier mounting flange, proper flange throat clearances and full height tabs on frog ends to attach closure and frog heel extension rails.  The trade-off, mating rail parts require that the rail foot be removed to mate with the frog casting. #10 clearance bolt holes have been drill for rail connections. #8 bolts with nylok nuts are used for the final connection. The oversized holes provide a loose fit for the bolts. This makes future bolt removal easier.

(click photos or links for larger view)

Photo 10    Photo 11

Points: Photo 12 shows the switch point ends. ILS points are made of 1” stainless steel angle (see criteria 4 & 5). This material doesn’t rust, needs no lubrication and lets Mother Nature clean when it rains. Some club members were concerned about wheel contact area on the narrow edge of the angle. The distance a wheel travels on the angle edge alone is very short. The backside of each point is tapered to “nest” in the stock rail. After milling, the tip of the point is about .062” thick (half original material thickness). This is enough material for wear without machining a knife-edge that can crack or break off. Throw bar mounting hole(s) are drilled and de-burred. The closure rail connecting bolt hole is drilled during the turnout assembly process.

Photo 12

Stock Rail Notching: Photo 13 shows fixture used to machine the “notch” in the stock rails (left and right). These are the mating notches for the switch points. This notch is a taper as well. The fixture holds the rails in place at a slight angle on the machine bed during the milling process. In time, the notch in the stock rail will be worn down by the passing of wheel flanges. Photo 14 shows the stocks rails after this step of the machining process.

Photo 13    Photo 14

Heel Block Mounting: Photos 15 & 16 show the location where the stock rail is machined for the heel block(s). The heel block holds the stock rail and adjacent closure rail together at the proper distance. The stock rail and closure rail heel block mounting holes will be drilled during the turnout assembly process. Photos 17 & 18 show how the point end of the closure rail is machined for the heel block and eventual attachment of the switch point. The closure rail end taper provides extra clearance for the back of wheel flanges as they pass over the heel blocks.

Photo 15   Photo 16   Photo 17

Photo 18

Frog Rails: Photo 19 shows how the frog end of the closure rails and frog extension rails are machined. If you recall, the frog casting does not allow the foot of the rail to be located under the casting. This extra step in the machining process ensures the strongest possible frog casting.  Once again, the trade-off is a little extra work on the frog mating rail components. Rail end bolt holes will be punched during the turnout assembly process.

Photo 19

Tie Material: Club members will sometimes visit local lumberyards at the end of the season to “clean up” treated lumber that was cracked or checked. This sometimes yields a stack of lumber that can be purchased for 50 cents on the dollar or better! In necessary, the club will purchase a “bunk” of 2x6 boards (64 total) at one time. The ILS uses (4) 8-foot long, 2x6 boards for each turnout. After the boards are cut to their various lengths, they are ripped in half to make the ties needed.

Tie Spacing Jig: Building anything in a “controlled environment” is easier than building something on the ground. The ILS has a special tie spacing jig for turnouts. This jig was built with a 27 ties per 10 feet of track as opposed to the club’s regular track building jig that is built for 25 ties per 10 feet of track. After determining whether a left hand or right hand turnout will be built, the ties are arranged in the tie spacing jig accordingly (see photo 20).

Photo 20

Hole Drilling: Screw mounting holes are pre-drilled in the ties for the straight stock rail. Ties located in the point area and guardrail area, are NOT drilled at this time. Photos 21 and 22 show a simple fixture used to pre-drill pilot screw holes in the tie. Pilot holes are drilled for one rail ONLY using a staggered hole pattern. The other rail screw holes will be drilled during assembly. One of the fixture tie stops is adjustable to allow for rails with different rail foot widths. ILS has several different rail sizes and profiles. During the turnout assembly, the foot of the rail will be drilled in the point and guardrail areas. #10x1” hex head sheet metal screws hold the rails to the ties. These are driven with a hex head driver or better yet, a 3/8” Allen cap head bolt that had the threads removed. The cap head bolts can be heated and dropped in oil to harden. Without hardening, the bolt heads will wear after driving several hundred screws. A grinding wheel can be used to remove the worn part of bolt head to expose “fresh” edges.

Photo 21

Photo 22

     continued, click to read more

 

 

Article by Carl Baskin (ccvstmrearthlink.net)

(reprinted by permission of  the ILS web site)

 

the end

 

 


 

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