English to Russian Tech/Engineering Engineering: Industrial piling

Помогите, пожалуйста, с переводом: fresh heading

As test piles are required, the production pile lengths shown in the contract documents are for estimating purposes only and the actual lengths to be furnished for production piles shall be confirmed by the OWNER after the test piles have been driven and tested.
The lengths given in the order list provided by the OWNER shall include only the lengths anticipated for use in the completed structure.
The CONSTRUCTION CONTRACTIOR shall increase the lengths shown or ordered to provide for the fresh heading and for such additional length as may be necessary to suit the method of operation, without added compensation.

Заранее спасибо.