The Contractor agrees not to create or suffer to be created any mortgage, lien, pledge or other encumbrance upon any of the increased facilities, materials, supplies or other property for which the Government under the terms of this contract shall reimburse the Contractor, and which is in the possession of the Contractor, and further agrees not to permit or suffer any attachments, mechanics' liens or other liens or encumbrances to attach to such property or the articles, and in the event that any such attachment, lien or encumbrance is created, agrees to pay or discharge the same, to the end that all property which shall have been paid for by the Government, shall be and remain the free and unencumbered property of the Government, provided that nothing in this article contained shall require the Contractor to make any such payments so long as it shall in good faith contest the validity of the claim or claims therefor, and so long as the delivery of the articles is not interfered with, and provided further, that the Contractor shall give bond for the claim asserted.

The Contractor shall give due notice that all property which shall have been paid for by the Government, belongs to the Government.