Simplify the following text for a Grade 7 native English-speaking person.
Original: In the early planning stages of the line an articulated type of rolling stock was considered but the idea was dropped because of difficulties in transferring the stock to Acton Works for heavy overhauls .
Simplified: At first , an articulated type of rolling stock was considered . This idea was not used because it would have been to difficult to move the stock to Acton Works for heavy overhaul .