townsfarminstall

Installation Suggestion for the Townfarm Crossing

Approaching track

Set a level on top or your approaching roadbed (bottom of rail ties). Dig your site down to firm soil, at least 8". Compact this area, then, sculpt the soil creating low spots between the support locations and cut a channel that will drain away from the span. Spread the plastic sheeting, it should be long enough to reach the level on the ends and will be trimmed later.

With masking tape, mark support locations on the level, 23½" to the outsides of the abutments and 11¾" to center of middle support. Fill the area with 1" gravel within 6" of the level and compact. At the support locations, place a generous mound of gravel fines to within 3" of the level. Take one abutment and wiggle it into the fines staying flush with the level and on the tape mark. Check front to back with torpedo level. Repeat on the other end and center support. Backfill abutments with 1" gravel and top with fine gravel.

Bind pencils to top and non-detailed sides of beams.

Installation Suggestion for the Townfarm Crossing
The goal is support your track straight and level over the beams. You don't want the supports (abutments and center pier) to settle or shift. Here are some items that will ease the installation : 3' level, 8" torpedo level, masking tape, plastic sheeting 4' x 2', gravel-1" and 1/4", 4 pencils or dowels with 4 small rubber bands, two small stakes (2 more pencils ok), toothpick or sharpened pencil. Join the beams as shown below and set aside. First, determine the center of your approaching track and ties. Place the back edge of your level 1½" away from the center point and set a stake to hold it there leaving 3" above grade.. Do this for both ends. This will be the guide for aligning your bridge supports. The back edge of the level aligns with the back edge of the abutment platform.
	Approaching track
Set a level on top or your approaching roadbed (bottom of rail ties). Dig your site down to firm soil, at least 8". Compact this area, then, sculpt the soil creating low spots between the support locations and cut a channel that will drain away from the span. Spread the plastic sheeting, it should be long enough to reach the level on the ends and will be trimmed later.	With masking tape, mark support locations on the level, 23½" to the outsides of the abutments and 11¾" to center of middle support. Fill the area with 1" gravel within 6" of the level and compact. At the support locations, place a generous mound of gravel fines to within 3" of the level. Take one abutment and wiggle it into the fines staying flush with the level and on the tape mark. Check front to back with torpedo level. Repeat on the other end and center support. Backfill abutments with 1" gravel and top with fine gravel.
Bind pencils to top and non-detailed sides of beams.
Will your bridge will be viewed from one side or both? See below for alignments. This determines which way you will face the detailed side of the beams. Apply an exterior grade caulking to the beam intersections, enough to squeeze out in all directions and secure with pencils and rubber bands. Place beams on the supports and fine tune the supports to mate with the contact points on the beams. Remove beams and apply a generous amout of caulking to contact points and reset to the supports. When the caulking sets up- but before cure, use your toothpick to score the caulking making the excess easy to remove after curing. Because of the sealed surfaces, the caulking will have a weak bond. The intent is to create a gasket that will displace moisture and will release in the event the span takes a bump. Finally, trim your plastic sheeting, top the gravel with sand and gently water it in to lock your gravel. Set your track and ties.....Enjoy!