55 Pa. Stat. § 697.13
The Commonwealth does hereby pledge to and agree with any person or the Federal Government subscribing to or acquiring the bonds to be issued by the authority for the construction, extension, improvement or enlargement of any port facility, port-related project or property of the authority, or part thereof, that the Commonwealth will not limit or alter the rights hereby vested in the authority, until all bonds, at any time issued, together with the interest thereon, are fully met and discharged. The Commonwealth does further pledge to, and agree with the Federal Government, that in the event that the Federal Government shall construct or contribute any funds for the construction, extension, improvement or enlargement of any port facility, port-related project or property of the authority, or portion thereof, the Commonwealth will not alter or limit the rights and powers of the authority in any manner which would be inconsistent with the continued maintenance and operation of the port facility, port-related project or property of the authority, or the improvement thereof, or which would be inconsistent with the due performance of any agreements between the authority and the Federal Government, and the authority shall continue to have and may exercise all powers herein granted, so long as the same may be necessary or desirable for the carrying out of the purposes of this act and the purposes of the Federal Government and the construction or improvement or enlargement of the port facility, port-related project or property of the authority or such portion thereof.
55 P.S. § 697.13