I have documents that show most Amsterdam Directors' ships that were in use in 1652 and 1653. The only ship that seems to be missing is the Sint Matheeus that was captured by the English at the Battle of the Gabbard. I do have a number of documents that show the "other" Sint Matheeus, the one that was not captured. She was a somewhat smaller vessel.
The captured ship was called the Matthias in English service. The only reason we know some of her dimensions is because Dr. Weber published them in his book about the Four Days Battle. They were: 144ft x 36ft, with an unknown depth in hold (in Amsterdam feet). Her dimensions as measured by the English are well known. They were: 108ft x 32ft x 15ft. The length is that on the keel and the beam is that outside the planking. The Dutch dimensions are the length from stem to sternpost and the beam is that inside the planking. The English and Dutch depths also differ. The English depth is from the keel to the underside of the deck planking on the main deck, at the center. The Dutch "hold" is measured to where the deck meets the side, from the keel.
My "system" for converting between Dutch and English dimensions only "sort of works". I use factors derived from example ships where we know both the English and Dutch dimensions. You need to be perpared to round liberally, as well.
Factors:
- Converting English LK to Dutch L: 1.33
- Converting English B to Dutch B: 1.13
Depths are a problem, because unlike the other dimensions, there seems to be no consistency. Even with length and beam, we can find examples that fail this system. Still, it is a way to estimate Dutch dimensions where we only have English dimensions preserved.
In some cases, English D to Dutch D (Hold) works with 0.92 as a factor. Sadly, there are other cases where 1.07 works. In the case of the Clovetree (ex-Nagelboom), the depth conversion factor is something like 1.18. In other cases, a figure in between these works. The problem seems to be with the English measurements. The Dutch dimensions are generally "well known". In the case of Dr. Weber's book, however, there are so many typographical errors that one needs to be cautious. For example, the Dutch beam for the Ruiter van Gelder (VOC) is shown to be 29ft while the English beam is 35ft. If you multiply the English beam by the factor 1.12, you get a Dutch beam of 39ft, which is reasonable. That would mean that the 29ft is a typo, and should be 39ft.
