The State of California's GO bonds are full faith and credit bonds, to which the state's general fund, rather than any particular tax revenue, is pledged. A sinking fund is a fund containing money set aside or saved to pay off a debt or bond.A company that issues debt will need to pay that debt off in the future. Bonds may be serial bonds or sinking fund bonds with such maturities as the board may determine. The Union Pacific Railroad Company filed its petition in the Page 99 US 701 Court of Claims against the United States. The court found the following facts. The trustee must act quickly to secure any collateral, if the defaulted issue is secured. Case opinion for US Supreme Court IN RE SINKING FUND CASES. Read the Court's full decision on FindLaw. Bankruptcy Lawyer in California: Understanding Secured and Unsecured Debt.