Section H.1: What is hogging?
The terms “hogging”, “hogged” and “hog” refer to the sagging of the bow and sterm of a ship relative to its midships section. A ship that has experienced hogging is said to be hogged. Instead of showing a flat, level hull line, a hogged ship is “curved”, with the bow and stern lower than the center of the ship. Hogging is generally found in older wooden vessels, due to the natural weaknesses in their structure. However, a small degree of hog is not unheard of in iron and steel ships. Hogging occurs because the bow and stern of the ship, while carrying a considerable amount of heavy equipment, posses relatively little buoyancy. The center of the ship, on the other hand, possesses a great deal of bouyancy and may be quite light-weight if the ship is not loaded with heavy cargo or ballast. This unequal distribution of forces, with great weights but little buoyancy fore and aft, and little weight but great buoyancy amidships, leads to deformation of the hull.
