Ship Terminology and Nautical Archaeology: A Comprehensive Guide

Posted on Oct 8, 2024 in Geology

FORWARD and BACKWARD Positions on a Ship

FORWARD OF indicates a relative position equivalent to “in front of” or “before.” BACKWARD OF indicates a relative position equivalent to “behind” or “aft of.”

Regarding ship positions:

  • The forecastle is situated FORWARD (fore end of the ship).
  • The superstructure is usually situated AFT (after end of the ship).

ABOARD means in or on the ship (synonymous with “on board”).

The Nanhai No. 1: An 800-Year-Old Treasure

An 800-year-old merchant ship, the Nanhai No. 1 (or South China Sea No. 1), was raised from the bottom of the South China Sea. Loaded with gold, silver, and porcelain trading goods, this 30-meter wooden vessel may confirm the existence of an ancient maritime trade route linking China and the West.

Discovered in 1967 off the coast of Guangdong Province, the ship was buried under two meters of silt at a depth of 30 meters. It was hoisted by a barge in a steel basket, as high as a three-story building. The ship will be housed in a museum in Guangdong, within a tank called the “Crystal Palace,” which will maintain the same water temperature and pressure as the seabed. Visitors can view the ship through the tank’s sides.

The Marine Silk Road

The Nanhai No. 1 could provide evidence of a “Marine Silk Road” connecting China’s Guangdong and Fujian provinces to Southeast Asia, Africa, and Europe, similar to the overland Silk Road that extended to Central Asia and Europe. Like its overland counterpart, the Marine Silk Road served as a bridge between Eastern and Western cultures.

Rudder Types and Propulsion

  • A rudder with its entire area aft of the rudder post.
  • A flap rudder has a small portion that moves at a greater angle than the main rudder to increase maneuverability.
  • A semi-balanced rudder has part of its area forward of the rudderstock to reduce torsional stress.
  • The boss is the central part of a propeller where blades attach and the driving shaft fits.
  • The leading edge of a propeller blade opens the way through the water.
  • In twin-screw ships: the starboard propeller is usually right-handed (clockwise), the port propeller is left-handed (anti-clockwise). This outward-turning configuration reduces cavitation.
  • Jet propulsion draws water into the ship and thrusts it out at high pressure using a pump.

IMO Conference and Corrosion Prevention

The first IMO conference in 1960 addressed safety matters. A 1948 international convention on the safety of life at sea, organized by the UK, required updating. Corrosion prevention involves providing and maintaining a protective coating for a ship’s steel structure. Secondly, preventing electrochemical wastage, known as cathodic protection, is crucial. Two types of cathodic protection are commonly used: the sacrificial type and the impressed current type.

Historical Engine Development

Following Nicolaus A…’s work, the internal combustion engine became practical in the 1960s. Before the chief engineer’s involvement, the engine was being overhauled by the engineers. Since our departure, fuel consumption has increased abnormally, and the cause is still unknown.

Ship Construction Terminology

  1. Frames: Transverse members forming the rib-like skeleton of a ship, extending from keel to deck.
  2. Fore peak bulkhead: Vertical piece rising from the fore end of the keel, forming the topmost point of the forward sides.
  3. Beams: Transverse structural members supporting the deck plating, running athwartships.
  4. Bulkheads: Vertical partitions dividing the vessel into compartments.
  5. After peak: Large casting supporting the rudder and propeller shaft, attached to the after end of the keel.
  6. Hull: Plates forming the outer side and bottom skin of the vessel.
  7. Floor: Vertical plates between the outer and inner bottom, running at right angles to the fore-and-aft line from bilge to bilge, often with lightening holes.
  8. Rider plate: The strake adjacent to the keel (also known as strake A).
  9. Bilge keel: Longitudinal projection attached to the hull at the turn of the bilge, reducing rolling.
  10. Openings in a deck for passing between levels.