Diesel Set on Train 630, 5/14/04

Anybody know why this happened yesterday or is this normal equipment scheduling? I was expecting Arrows on this train. The consist was: 4130, C1 (didn't catch number), 1603, 5751, and 5111.

Ken,

I saw the same set pass Mt. Tabor while going to work. I don't know why it had a diesel set......

Sometimes they will use diesels on trains which are traditionally electric Dover-Hoboken trains or versa vice. This maybe because they are making an equipment move or they had a problem with their train and grabbed the next available one. But, my guess they were making an equipment move and thus killing two birds with one stone.