1713. A Weld-Stud/Stud-Pad Method for Foundationing Lightweight Shipboard Equipment

Paper

Abstract

The introduction of new and advanced equipment, and the growth of supporting systems such as cooling water and ventilation aboard ship, provide today’s weight engineer with a constant challenge to develop means to control and reduce ship displacement. The sheer volume of equipment installed on a modern ship dictates that efficient, cost effective means be employed when foundationing this equipment. Standardization of foundations for similar items is not only desirable, but is necessary in order to maintain efficiency and control weight. Standardization of foundations, however, can lead to a situation where the support system is designed to suit a range of equipment sizes and weights. This results in foundations which are adequate at the high end of equipment weight, but overdesigned and excessively heavy at the low end of equipment weight. This paper describes the development of a lightweight foundationing system, developed by Ingalls Shipbuilding, Division of Litton in Pascagoula, which utilizes weld-studs and stud-pads in a wide range of applications for equipment weighing up to l00 pounds. Although weld-studs and stud-pads have been used in the shipbuilding industry for many years, the problem which has existed has been the lack of data providing direction on the load carrying capacity of these systems. Varying conditions caused by equipment stand-off from the mounting surface, equipment weight, center-of-gravity location, fastener size and type of material, have raised many questions as to the adequacy of stud-type foundations aboard ship. 1ack of data has resulted in the ripout of some installations because insufficient information was available to prove the adequacy of the stud/pad foundation. The system developed by Ingalls provides the user with a pre-engineered set of tables which contain load-carrying capacities for a wide variety of equipment in a broad range of mounting conditions.