with the conditions in which we would expect a 7,000-horsepower tug to be able to hold a large tanker.

It is important to note that the wave drift forces increase dramatically up to a 33-to 39-foot (10- to 12-meter) sea state. In these conditions the relative dynamic motions of the tug and tanker would preclude the tug from towing regardless of its horsepower. Even the largest oceangoing tugs cannot continue to tow in major storm conditions.


1. OCIMF. 1981. OCIMF Recommendations on Equipment for the Towing of Disabled Tankers. London: Witherby and Company.

2. Hancox, David. 1987. Reed's Commercial Salvage Practice. Sunderland, England: Thomas Reed Publications Limited.

3. Noel, John V. 1977. Knight's Modern Seamanship, Sixteenth Edition. New York: Van Nostrand Reinhold Company.

4. Hogben, N. et al. 1986. Global Wave Statistics. England: Unwin Brothers Limited.

5. OCIMF. 1992. Users Guide OCMOTA. Maritime Research Institute Netherlands

6. OCIMF. 1977. Prediction of Wind and Current Loads on VLCCs. London: Witherby and Company.

7. Dai, Richard Y. T. et al. 1981. Offshore construction barge performance in towage operations. Proceedings 1981 Offshore Technology Conference. OTC 4164.

8. Blight, Graham J. et al. 1978. Resistance of offshore barges and required tug horsepower. Proceedings 1978 Offshore Technology Conference. OTC 3320.

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