40 U.S.C.chpater 37, Contract Work Hours and Safety Standards, requires that certain contracts (see 22.305) contain a clause (see 52.222-4) specifying that no laborer or mechanic doing any part of the work contemplated by the contract shall be required or permitted to work more than 40 hours in any workweek unless paid for all additional hours at not less than 1 1/2 times the basic rate of pay (see 22.301).