I have sailed with an engineer who served his time in a sewing machine factory and another who was a Blacksmith only it wasn’t in a shipyard it was a Smithy. He was a professional 3 engineer and by all accounts a good one. He would have been well over a 100 today if still alive. A Chief who I sailed with on a few ships , now dead, was a time served electrician in the shipyard another one well knowing his job. A second mate I had with me when I was mate was a shipwright by trade and had a mates cert. it was his intention to get his masters and then start again in the engine room and try and make history by having both certificates . Whether he succeeded or not I never heard . Hope he did. Cheers JS PS his name was Tom Smith from Wallsend.. JS