The Sint Jan and Sint Joris

The Zeeland hired ships Sint Jan and Sint Joris were both armed to a similar plan. The Sint Jan was the ship commanded by kapitein Laurens Lispensier and the Sint Joris was a Scots frigate commanded by Jacob Wolphertszoon. They both had 2-9pdr guns and a main battery of 6pdr guns. They both also had 4-4pdr and 2 or 4-3pdr guns. By my standards, they were both lightly armed. The Sint Jan was assigned to Michiel De Ruyter's fleet in the summer of 1652 and fought in the Battle of Plymouth. The Sint Joris operated with Tromp's fleet and made the voyage to the Shetlands in July and August. I was amazed to see just how many Dutch ships in 1652 and 1653 relied primarily on a lower tier of 6pdr guns. From the published literature, I would have thought that they all had a lower tier of 12pdr guns, which was still lighter than the typical English ship, which was said to have at least some 18pdr culverins on the lower tier.