Pig rails in the whelping box

I was just wondering how many breeders on here use 'pig rails' along the edge of their whelping box to prevent puppies getting trapped against the side of the box by the mum?

Has anyone had bad experience from not using them?

Do you think they are necessary for all sizes of schnauzer?

I never used them,and never get puppies trapped against the side of the box by the mum.
But my females are lovely mums

Don't use them, never had problems.

The same for me, i don't use it and no problem ....

Schnauzers mus be good mothers, we don't use them either and we never had any problems.

No problem here either, but I would be more concerned if I had the larger versions of schnauzers, particularly Giants.

I had problem with Too Much Caring Mum, laying with her fat po on puppy....but had luck and got puppy back to life.
I would use this rails in future.

I do feel happier having the bars in the box, even if mum does use them mostly for resting a leg on so the pups can get at the milk bar easier!