help! massive loss of feathers - is this normal??

[sus9441]

recently 2 of my hens are loosing a lot of their features!!!! IS THIS NORMALLL??
they are like 1 and a half years old

 

[Ravynscroft]

Considering all the new pinfeathers visible all over them, I'd say they're just going through a hard molt... some lose their old feathers slowly and replace them slowly, others drop them just about all at once and get their new ones quicker...