Site Network: Main Site | Mail Access | Site Map

Shipbuilding:

Hopper Engineering Associates has been active in the shipbuilding industry since the mid 1990's. Our clientele includes small and large shipyards as well as independent vessel owners and operators. The company offers a diverse project history and team of experienced engineers.

Shipbuilding Industry In Depth:

Hopper Engineering Associates provides multidisciplinary civil, structural and mechanical engineering support to the shipbuilding industry. Our expertise is in extending the service life of aging facilities as well as upgrading facilities to accommodate larger vessels. Further, HEA is experienced in analyzing shipboard structure and components subject to unique operational sea state environments.

The following project examples summarize our experience, however, are in no way comprehensive of our expertise. Please direct specific questions regarding project experience to David Hopper, Managing Principal.

Featured Projects:

Shipbuilding ProjectsA large container ship was to be erected in a dock, which was designed for construction of a much lighter ship. HEA designed a spreader beam to distribute the ship's weight across sixty locations on the dock slab. The beams allowed for very large loads to be transferred from the ship's stern to the dock slab without damage to either the ship or the slab. Our calculations considered soil, slab, beam and ship stiffness.

Shipbuilding ProjectsHEA designed an adjustable spreader to be used with a shipyard's 300-ton cranes. The spreader employs a self-contained ratcheting system, which allows easy adjustments to accommodate different-sized loads. The spreaders are in service, where they have proven their utility in streamlining shipyard operations.

Shipbuilding ProjectsThe flow from a fireboat foam pump system was not adequate. HEA evaluated the system and found the cause of the poor flow to be a pressure drop in the system. HEA recommended enlarging the foam feed piping from 1.5 inch diameter to 2 inch diameter and replacing the existing pressure relief valve with a pressure sustaining valve.

Shipbuilding ProjectsHEA performed a structural evaluation of the T-AKE vessel bulwark and its adjacent ship structure under the 26" lizard line cleat design load and sea state 5 loading conditions. A finite element model of the bulwark and adjacent ship structure was modified to reflect critical changes to the design. Results of the analysis showed that the stresses in the bulwark and adjacent ship structure were within the allowable stress.

Shipbuilding ProjectsDeck plate thickness wastage was observed in a shipyard floating dry dock. HEA evaluated the admissible floater deck plate wastage. Stress and buckling limits were established. The existing deck plate thickness wastage was deemed acceptable.

Shipbuilding ProjectsAdjustable connections for several bolt sizes are required for mounting shipboard equipment in a vibratory environment. HEA designed adjustment plugs that allow for connection of bolt holes with poor alignment and provide slip resistant vibration mounting integrity. Finite element design optimization was used. The adjustment plugs are in use for equipment mounting as well as ship assembly.

Shipbuilding ProjectsIt was desired to extend the length of a carriage way to accommodate hauling larger barges. HEA designed an extension of the existing rail system, which integrated fully with the existing rail. HEA also designed an upgraded winch and pulley system to accommodate the larger barge loads.

Shipbuilding ProjectsIt was thought that waves generated by launching large vessels damaged a pier. HEA performed a detailed failure evaluation of the pier and demonstrated the damage was not attributable to launches. The damage was found to be caused by dry dock mooring loads during years of inappropriate service use. HEA recommended repair schemes for the pier.

Shipbuilding ProjectsThe admissible air draft for a ship passing beneath the bridges of the Carquinez Strait was not known. HEA established minimum air draft requirements for passing in and out of the Carquinez Strait during any one week. This information enabled the shipbuilder to add one meter of air draft to the vessel.

Shipbuilding ProjectsAn AOE-10 rejection notice was written on shipboard bleed air and auxiliary steam piping systems because pipe supports did not comply with established Navy shock mounting requirements. HEA performed detailed dynamic shock analyses (DDAM) for both piping systems. These systems were proven to be acceptable for shock and shipboard use with minor modifications.


Additional Spotlight Projects:

Below you will find additional Shipbuilding related projects we have worked on.