Propulsion Shaftline Bearing and Gear Teeth Failure Investigation on the "C" Class British Columbia Ferries
Bibliographic record
Abstract
British Columbia Ferry Services Inc. operates five "C" class passenger-car ferries that were delivered in 1976 (3 ships) and 1981 (2 ships). The vessels have a service speed of 19.0 knots, are 457 ft. long, and have a gross tonnage of 6,550 tons. They have a capacity of about 360 cars and 1,500 passengers. Their route varies from Vancouver-Vancouver Island-Sunshine Coast, with up to 9 round trips per day. The vessels have a double-ended single screw propeller configuration. Each of the controllable pitch propellers are driven by one or two diesel engines rated at 5,930 HP, through single reduction gearboxes. The two gearboxes are connected via quill shafts that are concentric with the pinion shafts. The pinion shafts are engaged via clutches at the end of each of the quill shafts. This arrangement enables one or both of the diesel engines to drive either one or both of the propellers. In 1998 a catastrophic failure occurred to the bull wheel on one vessel. The bull gear teeth broke off taking out both pinions. In 1999 the bull gear on another vessel was replaced as a result of fractured gear teeth, found during an inspection. In addition, a number of failures have occurred to both the lineshaft and pinion shaft bearings. An investigation was conducted to determine the source of the failures and the most prudent and economical course of action. To accomplish these objectives a review of the system design and maintenance/failure history was conducted, as well as theoretical modeling and alignment and vibration measurements. It was found that the failures occurred due to misalignment. A realignment program has been undertaken, with the first realignment completed in February 2002. This paper describes the failure investigation and the results of the realignment work conducted.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.004 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".