ANALYSIS: CRUISE SHIP LIFEBOAT ACCIDENT. WHAT WENT WRONG. HOW TO PREVENT FUTURE ACCIDENTS
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| The Last Life Boat Launched From The TITANIC |
We don't want to appear like we are rushing to judgement since to the layman a sudden failure of a cable or hook used to raise and lower a life boat looks like an inexplicable event. That wasn't the view of the forensic examiners of the American Admiralty Bureau, investigators and causation analyst of such events for two decades and publishers of the American Admiralty Bureau COMMENTATORS which we are re-publishing gradually in our AUTHORITATIVE LITERATURE SECTION. The Bureau addressed "rigging failures" in AMERICAN ADMIRALTY BUREAU COMMENTATOR VOLUME 3 , COMMENT NO.4 (Cite as AAB COM. NO1, VOL3 (1996) ISBN 1-879778-59-9). Where they noted ,in part:
Life boat "falls" are a species of "running rigging", that is wire or cordage rove through blocks, tackles, pulleys, around "buttons", or through "chocks" to achieve "mechanical advantage" when handling heavy weights. Mechanical advantage can can be rather precisely calculated mathematically in advance of handling any heavy load. Likewise, the breaking strain and safe working load of the wire or cordage itself used in the running rigging may be precisely calculated. The prudent boatswain or deck officer then selects from his cordage or wire supplies a diameter and "lay" of the cordage or wire to achieve the recommended "safety factor". For example in any application where human beings may be suspended with the load as is the case with life boat falls many authorities recommend a safety factor of 7, that is 7 times the breaking strain of line or wire that needed at a minimum to handle the weight. Typical safe working loads are often five times the calculated breaking strength of the line even for inert loads. So there is a lot more to the selection of a wire for use in a boat fall than just simply assuring that the breaking strain is basically stronger than the load. Maintaining the mandated wide margin of safety is a function of regular inspection, generally weekly.
Adequate inspection involves more than just a visual look over for "fish hooks" in wire, or color changes or diminished over all diameter in cordage. In the case of wire boat falls, cargo whips and similar wire running rigging some precise data is needed. When the ship was first designed the naval architect, or the designer of any off the shelf boat davits or cargo booms or cranes professionally computed the breaking strain, safe working load, and safety factors for the rigging and placed a wire or cordage specification into the documents delivered with the equipment. In times past, astute ship's officers and boatswains on a newly commissioned ship not only took pains to safe guard such documents but also transferred all such specifications into a hand written, hard cover, bound ledger type book called "The Original ship's Allowance List".
Unfortunately you don't find many of those around any more. The Chief Officer on a merchant ship assisted by the boatswain, or the "First Lieutenant" assisted by his senior boatswain's mate on a naval vessel, inspected the running rigging at least once a week when in use, not only by looking over the rigging visually for signs of wear but by taking a caliber to the strands and checking for diminished diameter of percentage of the strands, not just diminished overall diameter of the wire. Wires were replaced when a certain percentage of the individual strands showed diminished diameter based on manufacturer's recommendations as described in the Original Ship's Allowance List. Wire will show diminished strength on this type of test long before the entire wire shows measurable diminished diameter. Wire would also be lubricated during these weekly inspection cycles.
Often wire ( "Wire rope") has a fiber core that holds lubricant. When the wire is under strain it literally squeezes lubricant out. On weekly inspections a dry core to a wire used in a boat fall or cargo whip was cause for grave concern. How long had it been dry? How much had the wire been damaged by dry operation?
Unfortunately you don't find many of those around any more. The Chief Officer on a merchant ship assisted by the boatswain, or the "First Lieutenant" assisted by his senior boatswain's mate on a naval vessel, inspected the running rigging at least once a week when in use, not only by looking over the rigging visually for signs of wear but by taking a caliber to the strands and checking for diminished diameter of percentage of the strands, not just diminished overall diameter of the wire. Wires were replaced when a certain percentage of the individual strands showed diminished diameter based on manufacturer's recommendations as described in the Original Ship's Allowance List. Wire will show diminished strength on this type of test long before the entire wire shows measurable diminished diameter. Wire would also be lubricated during these weekly inspection cycles.
Often wire ( "Wire rope") has a fiber core that holds lubricant. When the wire is under strain it literally squeezes lubricant out. On weekly inspections a dry core to a wire used in a boat fall or cargo whip was cause for grave concern. How long had it been dry? How much had the wire been damaged by dry operation?
You see "wire rope" as used in boat falls, cargo whips and other running rigging is actually a machine full of moving parts and if not maintained and inspected is prone to failure supposedly without warning. Modern shipping companies are notoriously lax on inspection and maintenance of running rigging. Most shipping now is under "Flags of Convenience" or "Open Registries" for the express purpose of hiring the cheapest available officers and seamen possible on the world labor market. Crews have been reduced to the minimum needed to stand the navigation watches and handle the lines in and out of port. Much of the maintenance is done by contracted shore gangs only when there is visible wear and tear. There has been a lot of technological progress on coatings and electronic navigation that facilitates some labor force reduction. But wire rope is still wire rope and subject to all the ills that it was heir to 50 years ago. If you don't inspect and maintain it, it simply parts at an inopportune moment often with fatal results.
Hooks also have a set weight under which they will open and safe working loads, and safety factors designed to keep particular loads under control and avoid hook failure. Hooks are subject to wear and tear as well as wire rope is. If you don't inspect and maintain them, they fail.
While the cerw size of cruise ships is impressive in terms of the total number of crew, most are involved in the hotel services aboard. Generally cruise ship crews are minimally manned in terms of actual mariner crew members. The numbers of able seamen carried on a cruise ship usually reflect the number needed to properly man the life boats, not for inspection and maintenance of the physical condition of the vessel.
Admiralty lawyers engaged in rigging failure cases should carefully consider that the general standard of care for running rigging is weekly inspection against the equivalent specifications that were once found in the "Original Ship's Allowance List" but might be found in the manuals for the lifeboat falls, or cargo and line handling gear. Today it is more probable than not that this general standard of care is not observed. In cases where the general standard of care is more or less observed the accuracy of the specifications checked against should be checked. The Authoritative literature that should be consulted is complex. There are general references on marlinespike seamanship and rigging and then there is usually a need to consult with actual manufacturers manuals and end user literature. To just assume that a rigging failure is unpredictable is a lack of due diligence for an attorney. But to assume that hidden defect doesn't occasionally occur can lead to the case killing error of the empty chair defense. Be very careful in hiring expert witnesses for such cases. Make sure you hire someone who will tell you the truth and not what you want to hear. Remember even in the case of a manufacturer's defect, it is almost impossible to prove that it would never have been discovered even if the standard of care for maintenance and inspection were observed. Better a partial judgement from one party than to have your client turned away from the bench because of "the missing chair". Below are some links to relevant authoritative literature:
General:
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