Decks, Patios, Porches and Docks - FENCE PROBLEMS

I have the task of installing a 48 ft long x 3 ft high board fence on top of existing used railroad ties that are part of a retaining wall. I will be able use previously installed 4 x 4 posts that have been set set in concrete at each end of the 48 ft. but cannot remove the ties to set the in-between posts... Any ideas or thoughts would be appreciated.

tough scenario

I'd recommend mortising the railroad ties with a spade drill bit and chisel and then cutting tenons on the 4x4s say 1 1/2-2 inches thick by 8-12 inches long. Cut tenons on a table saw or with a circular and jig saw. Pin the tenon into the mortise with 2- 1/2 wooden dowels soaked in cuprinol preservative.

Labor intensive?-yes

All i can think of

HOpe this helps-----josh

PS if you can't get flared dowels ( i can't find them either) drill the first half of the hole pin with a 1/2 inch bit but then finish with a 3/8 to assure a tight fit :)

Hello
Install post bases on the railroad ties and set the post at each post back of railroad ties set a short post in concrete
and bolt the post together to give it extra support....you can do this with all-thread....all-thread a nut and washer
post nut and washer...space as need...nut and washer extra post nut and washer tighten every thing and it will hold it in place and is very strong and looks good if you make every thing the same hight and line all the extra post so each is the same from end to end....bolt should be about 12" to 18" up from the bottom of the post.......Good Luck