MO gave yeoman service on the GM ships. Trust a Dutchman to come up with good Dutch references. JWE sent me a link to where the Dutch GM, KPM, etc.. were discussed back in the beginning. Harald Velemans provided valuable input. The discussion has some concept explanations.
tm.asp?m=2179183&mpage=32&key=?
An interesting read. With a list presented like that you can easily see that the Dutch merchant marine wasn't having a great time during 1942.
Got full specs on almost all the Gouvernements Marine. You are right about the art. JWE used Castor as the basis, but should have used Merel for Sm GM, which is similar to Gemma/Eridanus Med GM but smaller.
Okay, that explains it.
Some (listed Bellatrix and ABC class) had 37mm. Strangely, those might well be AAC 37mm. MO is strongly inclined to agree with Hans Heesakkers on this.
I was aware of the 37 mm AAC gun but I didn't know any of the larger ships were outfitted with them during the war. Because of the accounts I've read about the lack of AA weapons on the GM ships I had assumed that the 3.7 cm guns would be some old vintage weapons. Not exactly uncommon that old turn of the century equipment was still in use during WW2 after all.
Revisiting everybody’s calculations. Most are good, some oddballs. Fixing quite a few. Working the auxiliaries, and have the finals for the Dutch. This is full/econ speed and maneuver fur the ships cardas wanted.
A bit suprised that they ended up which so much lower maneuver values than I'd anticipated. That's what I get for calculating the maneuver value with a more simplistic formula that has lower granularity I guess.
It does bring into mind as to whether the current maneuver value for the Chimo ACM (817) and Chimo YMS (818) is correct in that case. They are about the same size as the Sm GM but have a maneuver value of 48. The same with USAMP Bell (816). It might be worth taking a look at these classes anyway as the older USAMP Bell is given the same durability as Chimo despite having a 550 ton lighter tonnage value in the database.
Either way getting reasonable cruise speeds on these Dutch auxiliaries will be a welcome change. The slow cruise speed made them mostly useless within the context of the game.
Fuel and endurance are mutually dependent complicated by diesel/recip/turbine and oil/coal. SNAME has the fuel rates (lbs/hp/hr) for diesel/reciprocating/turbine engines for 1929 through 1946. Has Admiralty coefficients for the same period so an easy calculation to fill in the holes, assuming a relative relationship between IHP/SHP and kW. Relationships are known between oil and coal and diesel, so everything is expressed in equivalent metric tons of “fuel”, i.e., oil. The number relates bunkerage to mileage. So if you know bunkerage, you can get mileage and vice versa. If both are unknown, just pick a reasonable one and the other plops out. Maybe not perfectly accurate, but always consistent.
A very reasonable approach. I do the same for my fantasy mod, but of course I'm not held to your standards so my calculations are rather rough and primitive.
It does remind me of some fuel oddities I hadn't mentioned; the Bird (705, 706) and Bird AVP (779, 780) class to start with. Old ships with reciprocating engines having 6500 endurance at 12 knots with 200 fuel. I assume they ran on coal? Probably shouldn't have such high endurance at that speed.
Le Fantasque (774, 775) should probably have less endurance. France seems to have had some trouble getting decent range at slower cruising speeds. Interestingly they
might actually start beating the US destroyers in fuel efficiency at 30+ knot speeds despite being so far behind at lower speeds. Too bad that's not something you can model in the game.
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Also I'm afraid I forgot to respond to this last time, but...
MO began life as Dutch. He likes this stuff. His recent email -
Dutch guns have model numbers of their own. 6, 7, 8, 9, 10, are for different mounts and different sources but ballistically the same gun . Krupp built some, Bofors built some Krupp under license, Bofors built their own designs, HIH Siderius and Wilton-Fijenoord built Bofors under license. A Bofors 12cm/L50 Model 1924 became a Ducth 12cm/50 W-F No.6 or a 12cm/50 No.4 if it was early from Sweden and like that. I say the hell with the numbers just call them Bofors, or whatever they were. That is what I will do and run the ballistics. You want all the Dutch naval guns right? 75, 120, 150? The 8.8cm is our friend Siderius/Rheinmetall built by W-F from acquired parts after S went belly up. Or do you want the Bofors naval 88?
We’ll clean up the Dutch 150mm guns. MO has already run the ballistics based on the Bofors 15.2cm/L55 Model 1930, assuming Bofors ogival, propellant, shell and body weight are the same in Netherlands service. We’ll check the others as well.
How related the Swedish guns are to the Dutch ones seems like a very a tricky subject. The Swedish 12cm M24 guns used on the Ehrensköld -> Visby series of destroyers are often claimed to be of the same type as the ones on the Dutch Admiralen destroyers. However what little I know about them has me questioning whether that's actually true. A the very least the Swedish destroyer might have had a L/45 gun rather than a L/50.
Same story with the 15 cm guns. There's an old thread with photographs of the breeches of several of the Dutch 15 cm guns here:
http://www.network54.com/Forum/330333/thread/1127665400
Looks quite different to the Swedish 15.2 cm gun ogival screw breech to me.
As always my knowledge about these things are ultimately limited so I'll accept your word on it one way or another.
