Exam Question

### (a) Description of Crankweb Slipping and its Effects
**Description:**
A large marine diesel engine crankshaft is typically of a semi-built or fully-built construction, where crankpins and journals are joined to the crankwebs using a shrink fit. This process involves heating the web to expand it, inserting the cold pin/journal, and allowing the web to cool and contract, creating an extremely strong interference fit.
**Crankweb slipping** is the catastrophic failure of this shrink fit, where the web rotates relative to the journal or crankpin. This occurs when the crankshaft is subjected to a torsional moment that exceeds the frictional grip of the shrink fit. This results in a change in the angular position of the crankpin for the affected unit relative to the rest of the crankshaft.