Longitudinal Strength of Great Lakes Bulk Carriers

Although little statistical information is available regarding the actual wave conditions on the Great Lakes, considerable reductions are possible in the required scantlings of the present and future Great Lakes bulk carriers. Utilizing the available knowledge about the strength of ocean-going vessels and modifying this for the Lakes, rational formulas are developed for the required midship section modulus and moment of inertia. The present Lake strength norm for the large carriers is a linear extrapolation of requirements developed almost 50 years ago and has led to a required midship section modulus considerably in access of what is necessary. The formulas developed in this paper indicate that a saving of around 15 percent in the steel weight is possible within the present state of the art. As more detailed information of the wave spectrum becomes available in the future, further savings should be possible.