Ship calculations

This is an example of my ship calculations for four ships that fought at Lowestoft, in 1665. The Dutch measurements are all in Amsterdam feet, and are sometimes noted with a "D". The English are noted with an "E". I have found Excel spreadsheets very useful for analyzing 17th Century ship characteristics and for computing wargame factors.

 

 

Admiralty	Rotterdam	Amsterdam	Amsterdam	Amsterdam
Name	Eendracht	Amsterdam	Huis Tijdverdrijf	Huis te Kruiningen
Date	1653	1653	1655	1653
Captain	Jacob van Wassenaer	Abraham van der Hulst	Albert Claeszoon Graeff	Jacob Andrieszoon Swart
Guns	73	68	58	58
Crew	409	290	258	255
Length (M4) (Amsterdam feet)	150	140	136	140
Beam (M8) (Amsterdam feet)	38	34.5	34	34
Hold (M11) (Amsterdam feet)	15	14	14	13.5
Displacement (tons)	1035	820.8	787.7	781
Broadside Wt (lbs)	460	373	347	347
36pdr	3
24pdr	22	4	4	4
18pdr		20	20	20
16pdr
15pdr
14pdr
12pdr	6	8	4	4
10pdr
9pdr
8pdr	20	18	20	20
6pdr
5pdr
4pdr	22
3pdr		14	10	10
2pdr		4
Steenstukken/Bases
Armament Weight (lbs)	84.25	70.29	65.42	65.42
Armament percent of displ.	8.14%	8.56%	8.30%	8.38%
LWL (English) (M25) (feet)	134.12	125.18	121.60	125.18
WL (Dutch) (M18) (feet)	144.55	134.91	131.05	134.91
B (outside-D) (M9) (feet)	39.33	35.83	35.33	35.33
B (outside-E) (M10) (feet)	36.50	33.20	32.80	32.80
Mean Draft (E) (M26) (feet)	14.80	13.83	13.83	13.31
Draft Forward (M15) (feet)	15.00	14.00	14.00	13.50
Draft Aft (M16) (feet)	16.90	15.80	15.80	15.20
Lasts	394.01	311.61	298.32	296.13
Last coefficient	217.00	217.00	217.00	217.00
Jan Glete's approximation	993.87	786.03	752.51	746.97
English Length Keel (feet)	112.78	105.26	102.26	105.26
English Tonnage (tons)	799.22	617.16	585.16	602.37
Block Coefficient	0.5	0.5	0.5	0.5
Difference between methods	3.97%	4.24%	4.47%	4.36%

 

 

My assessment of Privateers Bounty is that it is too easy to damage enemy ships

I have been struggling to understand why the Dutch did better in the First Anglo-Dutch War than they do in simulations with Privateers Bounty. My latest theory is that it is too easy to inflict damage on enemy ships (generally). A counterpoint to that is that English 2nd Rates, such as the James and Triumph act as if they were super-dreadnoughts, in their ability to take Dutch fire and not take crew or hull damage.

I suspect that part of the issue could be that using the English burden as a defense factor may not actually be representative of real ship performance. Of course, I have been using a "hull value" for more than a decade, and it was based on dividing the burden by 3. So I have been doing the same thing, myself. I have used a variation of Paul Hague's detailed rules that I developed in 1990, so that I used his "firepower factor", which took the broadside weight, in pounds, and divided by 20. I calculate the "hull value" by dividing the English burden, in tons, by 3. Thus, the Mermaid (5th Rate), of 1651, would have a hull factor computed as follows:

hull factor = 286/3 = 95.

I always round the hull factor. For the "firepower", I do something different. I fix the calculation so that if a ship has a broadside weight greater than zero, then the minimum value is "1". The calculation is:

Round(0.5 + (BroadsideWt / 20)).

Namely, I add 0.5 to the result of dividing the broadside weight by 20, and round the result to the nearest integral value.

All the information in the scenarios is available

The ship definitions are all available in Word documents. I need to modify my Smalltalk code to extract the ships into separate files, based on their country (now that I understand the country codes). Still, I have most English and Dutch ships already extracted into Word documents, that I would make available, on request. The scenarios largely are documented in Word documents, as well, including the OOBs used. The OOBs are all scaled down to fit into the constraints of Privateers Bounty.

I wanted to say some more about my last post

One thing that is striking about the two lists of survivors is that the English were much more heavily damaged than the Dutch. The Dutch still had little choice but to concede, as there were so many more English ships, and they were generally more heavily armed.

A point to realize is that both the fleets started with approximately equal numbers. Of course, the Dutch fleet was much more lightly armed than the English. Even ignoring broadside weight and just counting guns, there was a great difference. The results, however, show the folly of facing ships with demi-cannon (32pdr) and culverins (18pdr) with ships mostly armed with 8pdrs and 12pdrs on the lower tier. There were a few exceptions. The East Indiaman Vogelstruis had 18pdrs on the lower tier. The Brederode had 4-36pdr, along with 24pdr and 18pdr guns. The upper tier was armed with 12pdrs, in her case.

The Dutch didn't fix their "armament problem" completely until the Third Anglo-Dutch War. In the second war, many "battleships" were armed with 18pdrs on the lower tier and faced English ships with demi-cannon. Finally, in the third war, De Ruyter's flagship had a complete lower tier of 36pdrs.