Converting English To Dutch
By
Friday, April 30, 2004
Converting Between English and Dutch Dimensions
February 14, 2003
Notes:
English keel length x (305mm / 283mm) x 1.237 = Dutch length from stem to sternpost
Example:
An example would be the Westergate (Friesland Westergo):
English keel length = 86 feet
Dutch length from stem to sternpost = 86 x (305/283) x 1.237 = 112 feet (Amsterdam). This is a plausible length, as there were a number of ships built to this length:
More Examples:
|
English Name |
Dutch Name |
Date Built (where known) |
Date Captured |
English Keel Length |
Dutch Length |
Dutch to English Length Ratio |
English Beam |
Dutch Beam |
Dutch to English Beam Ratio |
|
Black Bull |
't Wapen van Edam |
1665 |
86 |
120 |
1.395 |
28.33 |
28 |
0.988 |
|
|
Black Spread Eagle |
Groningen |
1665 |
103 |
130 |
1.262 |
30 |
31 |
1.033 |
|
|
Clove Tree |
Nagelboom |
1665 |
103 |
143 |
1.388 |
33 |
34.5 |
1.045 |
|
|
Delft |
Delft |
94 |
111-3/11 |
1.184 |
24 |
27-1/11 |
1.129 |
||
|
Golden Phoenix |
Vergulde Phenix |
113 |
160 |
1.416 |
36 |
38 |
1.055 |
||
|
English Name |
Dutch Name |
Date Built (where known) |
Date Captured |
English Keel Length |
Dutch Length & probable length |
Dutch to English Length Ratio |
English Beam |
Dutch Beam |
Dutch to English Beam Ratio |
|
Guilder de Ruyter |
Ruiter van Gelder |
105 |
140 |
1.333 |
35 |
37 |
1.057 |
||
|
Helverston |
Verhildersum or Hilversum |
103 |
136 |
1.320 |
33 |
34 |
1.030 |
||
|
House of Swede |
Huis te Zwieten |
110 |
146 |
1.327 |
36.5 |
36 |
0.986 |
||
|
Matthias |
Sint Matheeus |
108 |
144 |
1.333 |
32 |
36 |
1.125 |
||
|
Seven Oaks |
Zevenwolden |
105 |
136 |
1.295 |
35 |
37 |
1.067 |
||
|
Slothany |
Slot Hooningen |
112 |
160 |
1.428 |
36 |
38 |
1.056 |
||
|
St. Paul |
Sint Paulus |
84 |
130 |
1.547 |
25.5 |
28 |
1.098 |
||
|
Young Prince |
Jonge Prins |
90 |
120 |
1.333 |
28 |
28 |
1.000 |
||
|
Zealand |
Wapen van Zeeland |
93 |
116 |
1.247 |
28.5 |
28 |
0.982 |
My assessment is that the keel length for the Delft is wrong. I would say that 84 feet is much more plausible. That gives a ratio of 1.325. Perhaps there was a copying error, sometime in the past.
I also suspect the keel length for the St. Paul. A 94 feet keel length is more plausible, as well. The ratio then is 1.383.
I can imagine that the East Indiamen could have a greater rake than warships. The Prins Willem seems to show that characteristic. A quick estimate for the rake on the Prins Willem is 1.35 (length from stem to sternpost divided by the keel length, not tread length).
I can account for the House of Swedes beam ratio being less than 1.0 by the fact that the ship was girdled. The Dutch measurement, inside the planking, doesn't account for girdling. I don't really find the Black Bull's 31-foot Dutch beam very plausible. The ships built to that charter were more like 32 feet or 34 feet. Multiplying the English 30 foot beam by something like 1.056 gives you something that you could round to 32 feet. I am very confident about the Young Prince's Dutch measurements, so the English beam seems to be too great. I would have thought the beam should be something like 26, which would be a ratio of 1.077.
The average ratio for Dutch length to English keel length (disregarding what I believe are anomalous cases) is 1.34 (rounding 1.33975). The average beam ratio between the Dutch beam to English beam ratios greater than 1.0 is 1.067. That seems rather high, and is caused by including several ratios that appear suspect. If you disregard the ratios above 1.1, then you have a 1.05 average ratio (liberally rounded). However, I suspect we will want to see a larger beam, so I will use 1.067.
|
English Name |
Dutch Name |
Date Built (where known) |
Date Captured |
English Keel Length |
Calculated Dutch Length & probable length |
Dutch to English Length Ratio |
English Beam |
Calculated Dutch Beam |
Dutch to English Beam Ratio |
|
Arms of Rotterdam |
Wapen van Rotterdam? |
119 |
159.46 & 160 |
1.34 |
39.5 |
42 |
1.067 |
||
|
Welcome |
Welkom? |
82 |
109.89 & 110 |
1.34 |
29 |
31 |
1.067 |
||
|
Bear |
Beer |
106 |
142 |
1.34 |
26.5 |
28.25 (too narrow) |
1.067 |
||
|
Elias |
Elias |
1653 |
101 |
135 |
1.34 |
27.5 |
29.33 |
1.067 |
|
|
English Name |
Dutch Name |
Date Built (where known) |
Date Captured |
English Keel Length |
Calculated Dutch Length & probable length |
Dutch to English Length Ratio |
English Beam |
Calculated Dutch Beam |
Dutch to English Beam Ratio |
|
Indian |
? |
114 |
152.76 & ? |
1.34 |
33.67 |
36 |
1.067 |
||
|
West Friezland |
Westfriesland |
102 |
137 |
1.34 |
32 |
34 |
1.067 |
||
|
Mars |
Mars |
106 |
142 |