Movable Bridges e-bog

Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. For economy in the cost Of construction, Operation, and mainte nance, the time of Operation Should be made as long as feasible without inconvenience to traffic. The economic importance of allowing a rea sonable time for the operation of the bridge will be appreciated if it is remembered that the power required increases almost in inverse propor tion to the cube of the time for operation.