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Cheadle Hulme Model Railway Group |
Our Test-Track
| Purposes | Design Specs | Track Diagram | Building the Test Track|
Key Statement: To construct a cheap, easily erected and dismantled simple oval test-track in double-0, and to use this opportunity to establish the utility of the "blue foam" widely used by our trans-Atlantic cousins..
To permit the following to be done without having to erect Attam Bank:
- Program, test, and gain experience operating, DCC chipped locos.
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Field-test full length (10-coach or 36 standard wagon-length freights at least) trains, including checking that close-coupled stock will negotiate Attam Bank’s minimum main-line radius and the medium-radius cross-overs in the fiddle-yard.
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Members and visitors to test-run own locos and stock, both DCC and DC.
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Run-in new or refurbished locos, while monitoring performance.
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Members and visitors to "fun-run" older locos and stock not suitable/convertible to Attam Bank running standards (hence code 100 trackage).
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Provide an extra "facility" at public running sessions.
Possible Future Developments
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Insert graduated timber supports between baseboards and table-tops, to elevate one end of test-track to simulate 1:100 bank, for testing purposes.
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Add an N-gauge circuit in centre if need arises [now done].
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Add cheap "toy" lift-off scenic items to add child-interest during public running sessions -specially at Christmas when we hope to encourage youngsters to come and run the new locomotives they have received for Christmas.
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Use to trial methods for loading pre-prepared trains onto layout from cassette systems.
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Baseboards: |
Six 2ft by 4ft by 3in. thick (nominal) "blue foam" sheets, glued in pairs using "No More Nails", edged with protective glued-on 4mm. ply strips, to form three 4ft by 4ft "boards". Adjoining corners have 2in. by 1in. wooden inserts glued in place, to give purchase for the brass pins fixing the ply-strip ends, and for the screws holding joining clips for horizontal alignment. The outer corners have 1 in. wooden inserts to take the brass pins. Vertical and transverse alignment is by three Rural Railways brass locator pins and sockets per board join. |
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Trackage: |
Peco track; outer oval circuit of code 75 (minimum end radius 21in), inner circuit of code 100 (minimum end radius 18 in), with a train layby, programming spur and a code 75 cross-over point on outer track, to check back-to-back and flange clearances on stock proposed for Attam Bank. |
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Wiring etc.: |
Surface-wired (in grooves), with feed and (optional) metering switchable between DC and DCC operation. Power supplies and controllers plugged in as required. Point-work to be hand- operated via the wire-in-tube method.
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Materials and Costings
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"Blue Foam" [Dow Floormate 200-A, 80mm by 500mm by 1200mm [23.5/8" by 47.1/4"] purchased from Jewsons, Handforth Dean - £19.10
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Plywood casing - 4mm ply (one sheet 4' x 8') £9.93
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"No More Nails" glue, one tube (this is safe on polystyrene, and has done the job well) : £2.99
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4 pairs of Locking catches purchased from Squires [red book code = 601-970] : £7.96
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24 brass dome-head 3/4" brass screws to secure catches : £1.13
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Code 100 track and points: donated by member.
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Code 75 track: in stock - surplus from Attam Bank.
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One code 75 small radius point: in stock.
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Six pairs of brass locator pins/sockets (from Rural Railways, £1.10 pair)
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wire, brass pins, plug-sockets and meters: in stock.
- Supports: already available at clubroom.
Total: ca. £48
[Drawn by our new junior member, putting us oldies to shame!]
See Home Page for latest info.
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COMPLETED: 1/ Blue foam blocks have been stuck in pairs, making three 200cm x 200cm blocks.
2/ Corner-blocks fitted. Method: Recesses cut in foam to accept the wooden soffits (we found a razor saw the best implement for this) and the wooden soffits glued in place.
3/ Ply strips fastened to edges of foam boards. Method: Foam board stood on end, strips of ‘No More Nails’ applied to uppermost edge, including the face of the wooden insert; ply strip positioned at one end and fixed in place using 3/4" brass pins, then pressure applied from pinned end towards the unpinned end until ply firmly stuck to foam, when the far end was pinned to its block.
The ply strips were made slightly longer than the foam boards, so the excess was cut off flush using a junior hacksaw and sanded smooth. The foam baseboard was then rotated 90 degrees and the next ply strip applied as above, but overlapping the end of the previously fastened ply strip.
The ply strips used on the outer (non-mating) edges of the foam boards are mounted flush with the bottom of the foam, and project ca. 1cm. above the top edge (to stop small items rolling off).
The ply strips used between the board when mated are again mounted flush with the bottom edge of the foam, but finish some 10mm. below the upper surface of the foam (see 4a below). Before mounting these strips they were clamped together in pairs and pre-drilled with xx in. holes, giving a push-fit to the brass locator pins and sockets used to align the boards together.
4/ The locking clips have been screwed to the boards to clamp them together. Blunted short wide-head nails are dropped into the locking holes, to prevent the boards being unclamped accidentally while in use (at open days small padlocks will be used to prevent tampering by little fingers).
IN PROGRESS:
4 (a) Crossing baseboard joints: Method: Initially we intended letting in 12 in. long, 3/4 in. wide and xx in. thick wooden soffits at the edges of the foam boards where the track would cross the baseboard joint, the intention being to pin the track-ends to these for stability. However, after the first soffit had been fitted we had second thoughts.
At the baseboard joints the foam blocks are slightly (1 - 2mm.) vertically out of alignment [this is dimensional variation inherent in these building trade blocks]; we first thought we would fit the soffits level and then chamfer the boards to make them even, but in the event we found that shaving the foam was quite difficult to do with accuracy.
However, a better alternative was suggested, to use ‘drop-in’ track sections, held by sliding rail-joiners, to bridge the baseboard joins. By making these about ten inches long and allowing them to float we found vehicles crossed the uneven joints with ease - so we are proceeding with that method.
Initially we planned to arrange the joiners to slide fully onto one end of track, and slide them out when fastening the floating section - but a) this proved not at all easy, and b) it proved all too easy to damage the joiner in the process]. Therefore the rail-joiners are soldered to the track fixed on the boards, with half of the joiner projecting . To marry the boards, the floating track-sections are pushed into the joiners on one board, and then the next board is offered up, guiding the free ends of the floating track-sections into the fixed joiners on that board. The final connection is made when the board locking clips are snapped shut. Unfortunately this didn't work - fresh idea being tried, watch this space.
24th May 2007 - As you will see from our News section on the homepage, we have decided to shelve work on the test-track while we concentrate on getting trains running round in both directions on Attam Bank. The test-track will only be worked on when any member cannot usefully do anything on Attam Bank without impeding other work on the layout.
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