Why is 'had had' used?

[Tan Elaine]

We learnt the next day he had had to hand in his uniform and get off the job as fast as he could.

Would it be correct if 'had' is used instead of 'had had'?

Thanks.

[5jj]

It is the past perfect of 'have to', and is fine. The past perfect suggests that the having to hand in the uniform and the handing in happened before we heard about it. The simple past, 'had to' could be used if the handing in had not taken place when we heard about it.