From CBS today:

B.C. Ferries has cancelled 35 sailings on its busy Swartz Bay-Tsawwassen route through Sunday due to mechanical issues. The operator says there is a mechanical difficulty with the main engine’s propulsion system on the 60-year-old Queen of New Westminster, which was pulled from service Tuesday.

https://uk.news.yahoo.com/b-c-ferries-cancels-35-145834678.html

CalMac’s oldest comparable large ferry, though with bow doors to prevent flooding of the car deck, is the 41 year-old MV Isle of Arran.