Oak Island Yard work?

Everyday I come into Newark over Oak Island Yard on Rt21, and I notice some work going on at the start of the yard. Any ideas?

The peice of track that connects the Lehigh Line to the P&H Branch is known as the Back Leader. (CP-Valley to CP-Stock). It's only about 25-30 car lenghts long. The Back Leader is being double tracked to help the flow of traffic, this is what your seeing everyday.