I'm going through this at the moment too. August/September are by far the busiest months in my profession, to the point where we pretty much sacrifice dinner breaks and put in a shitload of overtime. And I've got a new colleague who constantly needs babysitting to the point it's driving me insane.
We had to book in a huge delivery yesterday and I decided to do it on my own which took around 3 hours. I could've had the new guy help me but he still doesn't grasp the booking-in process which meant it would've easily taken longer with two of us on the job.
Obviously management don't see that we're much too fucking busy to be babysitting new staff as they're on the golf course all day with their head in the sand not realising we're massively behind timetable.