Carroll’s arrival was in time for him to make his debut against Fulham on Saturday.
Speaking to WHUFC.com Carroll admitted the lure of first-team football was one the main reasons for his move.
“It’s great to be here at West Ham and all signed up - I just can’t wait to get started now,” Carroll said. “I want to be playing games and obviously hoping to score some goals. I know the manager well and some of the lads, so it is nice for me to come to a place where I know people.
“I’m hoping to add a lot of goals and create a few chances. I know Sam from Newcastle and he was a massive reason for me coming. When I worked with him at Newcastle it was great so it was a no-brainer really.”