In the discretion of the Authority any bonds issued under the provisions of this chapter may be secured by a trust agreement by and between the Authority and a corporate trustee, which may be any trust company or bank having the powers of a trust company within or without the Commonwealth. Such trust agreement or the resolution providing for the issuance of such bonds may pledge or assign the revenues to be received, but shall not convey or mortgage the port facilities or any part thereof; provided, however, the Authority may make a purchase-money agreement giving a chattel mortgage or lien on personal property or operating equipment purchased for use in its facilities. Such trust agreement or resolution providing for the issuance of such bonds may contain such provisions for protecting and enforcing the rights and remedies of the bondholders as may be reasonable and proper and not in violation of law, including covenants setting forth the duties of the Authority in relation to the acquisition of property and the construction, improvement, maintenance, repair, operation and insurance of the port facilities or the portion thereof in connection with which such bonds shall have been authorized, the rates to be charged, the custody, safeguarding and application of all moneys, and conditions or limitations with respect to the issuance of additional bonds. It shall be lawful for any bank or trust company incorporated under the laws of the Commonwealth which may act as depository of the proceeds of bonds or of revenues to furnish such indemnifying bonds or to pledge such securities as may be required by the Authority. Any such trust agreement may set forth the rights and remedies of the bondholders and of the trustee, and may restrict the individual right of action by bondholders. In addition to the foregoing, any such trust agreement or resolution may contain such other provisions as the Authority may deem reasonable and proper for the security of the bondholders. All expenses incurred in carrying out the provisions of such trust agreement or resolution may be treated as a part of the cost of the operation of the port facilities or portion thereof.