Samuel Halpern
Member
A new article of mine dealing with the turning characteristics of Olympic and Titanic was posted in PDF format on the Titanic Research & Modeling Association (TRMA) website. It is called: She Turned Two Points in 37 Seconds. Based on data presented by H&W's naval architect Edward Wilding, we were able to recreate the turning circle of these ships with the helm put hard over at full speed ahead. We also were able to determine the performance during several zig-zag maneuvers where the helm is ordered shifted to the opposite side at a specified time following an initial helm order.
We also looked at the classic story of Titanic’s encounter with the iceberg and found that some of the conclusions in the British Wreck Commission report were not entirely consistent with information given by both lookout Frederick Fleet and QM Robert Hichens. We also show that QM Hichens’ claim that the ship had turned two points just as she struck the iceberg is inconsistent with his claim that he just managed to get the wheel hard over just as she struck. We also considered the claims of Fourth Officer Joseph Boxhall and QM Alfred Olliver, and how they fit into the overall picture.
We also looked into the dynamics of the initial impact with the iceberg and quantified the initial loss of energy that resulted from damage to the ship's structure. Furthermore, we showed that once the ship’s underwater hull form widened out to the full breadth of the ship, any remaining side contact with the iceberg would not be enough to cause any deformity in the shell plate, but would allow ice to be deposited through open port holes and onto windows as was observed in different parts of the ship.
Several appendices are included with show the details behind the various curves and data that is presented. Included in the appendices are the estimated hydrodynamic force acting on the ship's rudder when put hard over at full speed, the angle of heal of the ship during a full speed turn with hard over helm, the loss of speed due to added hydrodynamic drag as a function of drift angle during a turn, and what would be the expected force of the berg against the ship's side assuming the rudder is kept in a position to keep ship's hull pinned against the berg during an allision event.
Despite the length and technical detail of this article, I hope you will find the information that is presented to be interesting and informative.
We also looked at the classic story of Titanic’s encounter with the iceberg and found that some of the conclusions in the British Wreck Commission report were not entirely consistent with information given by both lookout Frederick Fleet and QM Robert Hichens. We also show that QM Hichens’ claim that the ship had turned two points just as she struck the iceberg is inconsistent with his claim that he just managed to get the wheel hard over just as she struck. We also considered the claims of Fourth Officer Joseph Boxhall and QM Alfred Olliver, and how they fit into the overall picture.
We also looked into the dynamics of the initial impact with the iceberg and quantified the initial loss of energy that resulted from damage to the ship's structure. Furthermore, we showed that once the ship’s underwater hull form widened out to the full breadth of the ship, any remaining side contact with the iceberg would not be enough to cause any deformity in the shell plate, but would allow ice to be deposited through open port holes and onto windows as was observed in different parts of the ship.
Several appendices are included with show the details behind the various curves and data that is presented. Included in the appendices are the estimated hydrodynamic force acting on the ship's rudder when put hard over at full speed, the angle of heal of the ship during a full speed turn with hard over helm, the loss of speed due to added hydrodynamic drag as a function of drift angle during a turn, and what would be the expected force of the berg against the ship's side assuming the rudder is kept in a position to keep ship's hull pinned against the berg during an allision event.
Despite the length and technical detail of this article, I hope you will find the information that is presented to be interesting and informative.