Marine Surveyors Lexicon


Please report any issues with this site to Lexicon Webmaster.

Wood Hull Plan Submittal

  1. Introduction

    This chapter is intended as a general reference and guide for submitting the plans for a proposed vessel to the Coast Guard. It is not a complete text on naval architecture or a commentary on classification society rules. Plans should be submitted in accordance with the appropriate regulations to the Marine Safety Center (MSC) in triplicate.

  2. Plan Review
    1. Plans for small passenger vessels of wooden construction are generally reviewed by the local Officer in Charge, Marine Inspection (OCMI). For vessels over 65 feet in length and/or vessels incorporating novel designs or specifications not entirely addressed by acceptable Classification Society Rules, plan review will be conducted by the (MSC).
    2. Lloyd's Rules and Regulations for the Classification of Yachts and Small Craft should be used as a reference for designs as well as application to existing vessels.
  3. Other Classification Society Rules And Standards
    1. Direct reference to Lloyd's Rules is based on the familiarity that Coast Guard inspectors and technical personnel have with reviewing a vessel designed to those standards. This does not prevent a design from being based on the rules of another classification society or on some other standard. The burden of proof rests with the designer to show, with thorough engineering documentation and logic, that a proposed vessel meets a level of safety at least equivalent to that prescribed by Lloyd's Rules.
    2. Another useful "historical" reference that may be used as a plan review guide is "Merchant Marine Safety Instruction 14-60" dated 14 April 1960. This instruction contains scantling tables for 500 wooden T-Boats up to 60 feet in length, which have been approved for routes ranging from rivers to oceans. The scantlings in this reference are from a sampling of vessels certificated based on years of satisfactory service similar to the present "Five Year Rule" noted below.
  4. The Five Year Rule
    1. Definition. The "Five Year Rule" is defined as: "When scantlings differ from such standards and it can be demonstrated that craft approximating the same size, power and displacement, have been built to such scantlings and have been in satisfactory service insofar as structural adequacy is concerned for a period of at least 5 years, such scantlings may be approved. A detailed structural analysis may be required for specialized types or integral parts thereof." Determinations for meeting this rule are made for each case on individual basis by the OCMI.
    2. Burden Of Proof . The burden is upon the designer or owner to show the similarities between the proposed vessel and an existing vessel. The Coast Guard approving authority may need documentation showing the similarities in size, power, displacement and scantlings, and may conduct a survey and/or underway check of the similar vessel's performance in the anticipated operating area. Scantlings can vary greatly for similar sized wooden vessels depending on materials used.
    3. Satisfactory Service. The service life of small passenger vessels vary greatly depending on location, maintenance, and use. An inner harbor tour boat experiences a vastly different service environment than does a deep sea party fishing vessel, and is normally designed quite differently. An existing vessel used as a basis for a proposed new vessel should have experienced at least the same operating environment planned for the new vessel for five years, showing satisfactory service. A similar relationship of experienced service to expected service should be presented to the OCMI for an existing vessel changing service into Coast Guard certification.

Excerpted from Wood Hull Inspection Guidance (NVIC 7-95)