Raised Flower Beds built from Railway Sleepers, fixings?

[otgb]

I'm building some raised beds with new oak sleepers and cant seem to find a suitable fixing to hold them together, both at the corners where they meet at a 90 degree angle and when the two meet flush. Would you be able to use wall plates? or would a piece of lat or wood hold them together? All comments appreciated!

[T F McNeill]

I have raised beds, two sleepers high that a friend made for me. He hammered stakes into the ground and skew nailed the sleepers to them he also skew nailed them at the corners. This has been up for two years now and seems to be secure.
Tom