Railway sleeper raised bed for wheelchair access - ADVICE plz
 

I am after making a Railway sleeper raised bed for wheelchair access,
approx 8ft sq and 2ft high.

The old type of sleepers are creosoted, so thus I cannot use where
skin contact is likely, so I will have to use new ones.

But I have a few query's

1 - Are the old creosoted ones and the new tanalised ones, detremental
to plants ??

2 - I intend to overlap the sleepers at the corners, but how do i fix
them ??? together

3 - is there any need to fix into the ground, if so how ??

TIA