Dictionar Webster :
slab [1] (slab) n., v. <slabbed, slab-bing>
n.
1. a broad, flat, somewhat thick piece of
stone, wood, or other solid material.
2. a thick slice of anything: a slab of bread.
3. a rough outside piece cut from a log, as
when sawing one into boards.
v.t.
4. to make into a slab or slabs.
5. to cover or lay with slabs.
6. to cut the slabs or outside pieces from
(a log).
7. to put on in slabs or layers; apply


In dictionarul marinaresc pentru "slab" am gasit placuta dublanta, de rigidizare. Sensul este acelasi in in Webster, dupa cum se vede la pct 1,2 .
Desi sunt niste placute de rigidizare pentru sina de cale ferata.