greetings! just wondering if there is a right or wrong way to lay a plate girder bridge with connecting track over Chooch abutments and piers? I looked for some photos and it seemed like when the track transitions from the cordbed to the abutment it simply rests/glued on the “stone” surface of each Chooch piece. Is this acceptable?
Thanks
The bridge shoes should sit on the shelf (notched or top of abutment)
Most all of my abutments are fabricated. The base of these abutments is the wood riser that gets veneered w/ 1/4-3/8" plaster castings. The top or the riser has the notch for the bridge shoes. Where you mention a transition, the edge of the riser/ abutment has stripwood that acts as a gravel stop. This tends to fill in the void at the transition between the flex or handlaid ties to the bridge ties, and helps hold the ballast back.
These castings are just placed in this pic, need to be rough shaped, glued and final fit.
These shoes are actually hanging past the sub abutment as to sit on the top of the casting.
I don’t have a pic that shows the switch tie/ stripwood gravel stop.
Sometimes I can use a facing of the notched shoe shelf that will extend up to under the track to face the notch and act as the stop. This is styrene or wood and have even carved the stone look into it.
Another issue not to overlook, is the use of Micro Engineering’s bridge flex track. This would fit where you have an open deck for the bridge. MEs track has prototypical bridge ties. You just adjust the abutment shoe height to compensate. For
If you mean will it acceptably keep the track up, yes that will work but the prototype would not have the steel rest on the stone. there would be bridge shoes (or rollers) in part to handle the expansion and contraction of the metal during temperature changes. It would wear down the stone if it just rested on stone.
I recommend the book on bridges by Paul Mallery (carstens publishes it) that has been in print for probably close to 50 years.
There are some excellent castings of bridge shoes in HO but here is a picture of the prototype:
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The pic came from this very interesting website which has a wealth of photos for the heavy industry modeler
: http://www.jsw.co.jp/en/product/material/steel/steel_mp_indst_e.html
Dave Nelson
The shoes in the above post are correct for one end only. they are on the fixed end. the other end has to be able to expand and contract with the weather and consists of a couple of rollers. Typically they look like two or three pipes that have been cut in half and the haves reversed so the rounds are touching. the movement isn’t much but it needs to be taken into account when building a bridge.
I went for more of a “feel” for my abutments since I don’t think anyone will look too close.[:-^]For this 2 track set I used a chunk of 2"by4" and laminated a piece of 1/2"masonite to it then painted it a concrete color.Hope it helps!
Terry
