mariner freighters

[Buck Beach]

I'm nosing around and comparing some of the ships in AE with information of the Internet with the motive of maybe adding a few freighters to the OOB. I am finding that the tonnage listed of the RL ships are considerably more that those in AE. I am afraid that if I use the RL numbers I will be adding to much supply in relation to other in game ships.

What formula is used to figure the game ship size and capacities.

I understand if you are too busy to address this now. In that case I will wait until after patches 1 & 2 for an answer.

[DuckofTindalos]

In the game, tonnage is standard displacement, not full load.

[JWE]

ORIGINAL: Buck Beach
What formula is used to figure the game ship size and capacities.

Two separate questions and two separate answers: capacity first. Bulk cargo ship tonnage on the internet is given either as gross register tonnage (GRT - units of 100 cubic feet) or in the case of the military, sometimes in measurement tons (MsT – units of 40 cubic feet). Great advertising copy, but doesn’t give much indication of the weight capacity. The industry calls this Net Cargo Deadweight, Net Deadweight or Cargo Deadweight, and it’s in metric tons.

Just like tankers, it’s (Tot DwT) – (all the other stuff) = NCDwT

Fortunately, there are very exact and complete design specifications on US Maritime Commission ship designs as well as the War-I USSB Emergency Fleet. So a simple plot of design DwT vs design NCDwT for every design that could be found (including data from Mitsubishi for many Japanese) gave a very smooth curve that was extendable to all vessels of all sizes. The formula is:

NCDwT = 60%-65% (Tot DwT). Age, length, and performance are factors in determining where you are on the spread, but a decent swag is about 62.5% of DwT.

Make sure you get a real DwT, though. I’ve seen a gazillion websites and 90% of them are totally confused (and usually wrong) over the terms displacement, gross tons, deadweight, capacity. For example, how many times have you seen a Liberty ship as having a 10,000 ton cargo capacity? Actually, that’s very close to her total deadweight (10,200t) and probably represents her volumetric, expressed in Measurement Tons.

To help, I’m attaching a zip file with a Word doc, listing the Allied and Japanese xAK specifications – length, Dspl(fl), DwT, NCDwT, etc.. If you wish to add a ship and can’t find it’s technical documentation, just find something that reasonably corresponds to a list entry, and mod away.

[JWE]

Second part: cargo ship tonnage. This one was even more of a bitch because, as terminus says, warship tonnage is based on “standard” tons, and we wanted the merchies to have somewhat similar characteristics. Two problems with that. First merchies don’t have armor or guns, or any of that heavy stuff, so they are much lighter (on an loa basis) but also much larger (on a Dspl basis); Second is that merchie light displacement is given in two contexts; Dspl-Navy Lt, and Dspl-Maritime Commission Lt. Both have very different measurement parameters and neither has the same parameters as a “standard” tonnage measurement.

We had to factor both the loa and the Dspl differential because of the port and shipyard constraints. Remember; a merchie that is as long as a cruiser displaces maybe twice as much loaded, displaces about half as much empty, and is about 50% larger volumetrically.

Did calculations up the freakin wazoo, mostly plots and curve fits off design technical data.

Serendipity rears her head, and the best answer is “game tonnage” is (approximately) a function of “game capacity”. It varies maybe 10% one way or the other, but it’s close enough for a swag. I think the attached chart (above) will show how the tilt works for big vs small vessels. Wish I could give a hard answer, but there isn’t one.

[Buck Beach]

Thanks for the reply. I am talking about standard tonnage displacement. Here is just one example representing numerous differences. This one relates to bulk cargo capacity.

http://www.usmm.org/victoryships.html
"Three Victory ships (Logan, Hobbs, and Canada) were sunk during World War II, all by kamikazes during the invasion of Okinawa. These Victory's carried a total of 24,000 tons of ammunition (54 million pounds or 24,000 metric tons), including the majority of 81 mm mortar available in the United States. This loss severely restricted combat during the invasion."

The game lists these three ships as Victory Class but their aggregate bulk cargo tonnage is 20,800 tons.

Again this is just one of many examples (in fact all of the numerous I checked) of numbers not comparing and what led me to believe there is a formula for game use.

I am not trying to nit pick the database and definitely not looking for corrections. I again want to just use consistent compassions for my own inclusions into the data.

[JWE]

ORIGINAL: Buck Beach
Thanks for the reply. I am talking about standard tonnage displacement. Here is just one example representing numerous differences. This one relates to bulk cargo capacity.

"Three Victory ships (Logan, Hobbs, and Canada) were sunk during World War II, all by kamikazes during the invasion of Okinawa. These Victory's carried a total of 24,000 tons of ammunition (54 million pounds or 24,000 metric tons), including the majority of 81 mm mortar available in the United States. This loss severely restricted combat during the invasion."

The game lists these three ships as Victory Class but their aggregate bulk cargo tonnage is 20,800 tons.

Again this is just one of many examples (in fact all of the numerous I checked) of numbers not comparing and what led me to believe there is a formula for game use.

I am not trying to nit pick the database and definitely not looking for corrections. I again want to just use consistent compassions for my own inclusions into the data.

I understand exactly where you are coming from Buck. I ran into much the same thing when initiating this project.

You must understand that cargo capacity is reported in many, many, different ways, and the term “tonnage” has many, many, different definitions. The usmm website is pretty good, but it uses the capacity numbers that it extracts from somewhere else, without regard to capacity definition. The usmm website, and others, report data received from other places without much regard as to the physical meaning of the numbers – but that is not really their purpose, so why should they. Most websites are like this and don’t have a clue.

In your example, Logan, Hobbs, and Canada, had capacity defined, by the USN, in terms of Measurement tons, not metric, and the usmm website just picked up on the number, without regard to the measurement rule. It does not say 24,000 tons metric, it says 24,000 tons. These 24,000 tons are likely USN Measurement Tons, which is a volumetric and way less than what you really get.

I think the general Internet is the most horrid and utterly useless database in this regard. Once some site says “9”, then it gets replicated, ad infinitum, without regard to what “9” actually means.

I think we are a bit more intelligent than that, and hope you will be so, also.

[RyanCrierie]

Question. I have Norman Friedman's US Amphibious Ships, and it reports the Artemis (S4-SE) type as having a troop capacity of 252 men; yet in the game, 2240 S4 Artemis has 0 Troop Capacity.

What was the determinant for the game in adding "troop capacity"?

[Buck Beach]

ORIGINAL: JWE

ORIGINAL: Buck Beach
Thanks for the reply. I am talking about standard tonnage displacement. Here is just one example representing numerous differences. This one relates to bulk cargo capacity.

"Three Victory ships (Logan, Hobbs, and Canada) were sunk during World War II, all by kamikazes during the invasion of Okinawa. These Victory's carried a total of 24,000 tons of ammunition (54 million pounds or 24,000 metric tons), including the majority of 81 mm mortar available in the United States. This loss severely restricted combat during the invasion."

The game lists these three ships as Victory Class but their aggregate bulk cargo tonnage is 20,800 tons.

Again this is just one of many examples (in fact all of the numerous I checked) of numbers not comparing and what led me to believe there is a formula for game use.

I am not trying to nit pick the database and definitely not looking for corrections. I again want to just use consistent compassions for my own inclusions into the data.

I understand exactly where you are coming from Buck. I ran into much the same thing when initiating this project.

You must understand that cargo capacity is reported in many, many, different ways, and the term “tonnage” has many, many, different definitions. The usmm website is pretty good, but it uses the capacity numbers that it extracts from somewhere else, without regard to capacity definition. The usmm website, and others, report data received from other places without much regard as to the physical meaning of the numbers – but that is not really their purpose, so why should they. Most websites are like this and don’t have a clue.

In your example, Logan, Hobbs, and Canada, had capacity defined, by the USN, in terms of Measurement tons, not metric, and the usmm website just picked up on the number, without regard to the measurement rule. It does not say 24,000 tons metric, it says 24,000 tons. These 24,000 tons are likely USN Measurement Tons, which is a volumetric and way less than what you really get.

I think the general Internet is the most horrid and utterly useless database in this regard. Once some site says “9”, then it gets replicated, ad infinitum, without regard to what “9” actually means.

I think we are a bit more intelligent than that, and hope you will be so, also.

Then what can we, and what did you, use?

Oops, I see other posts of yours above after mine. I'll read them now and maybe it will clear things up for me.

Ok the just one more question then I will find a way to get a Kentucky windage comparable for any additions I might make. Where did you get the specs from that you have on the chart?

[JWE]

ORIGINAL: Buck Beach
Then what can we, and what did you, use?

Oops, I see other posts of yours above after mine. I'll read them now and maybe it will clear things up for me.

Ok the just one more question then I will find a way to get a Kentucky windage comparable for any additions I might make. Where did you get the specs from that you have on the chart?

Specs came from naval architects calculations, shipyard construction and measurement data, shipping company acceptance tests, some Navy measurements, all available, nicely bound and organized, with detailed construction plans, at:

Records of the US Maritime Commission Construction Division; Record Group 178, National Archives.

Records of the US Shipping Board Ship Construction Division; Record Group 32, National Archives.

There is a nice Regional Archive in Laguna Niguel, CA, just a few miles from my house. It has everything (or can get it in 2 days). People are very nice and helpful too.

[Buck Beach]

ORIGINAL: JWE

ORIGINAL: Buck Beach
Then what can we, and what did you, use?

Oops, I see other posts of yours above after mine. I'll read them now and maybe it will clear things up for me.

Ok the just one more question then I will find a way to get a Kentucky windage comparable for any additions I might make. Where did you get the specs from that you have on the chart?

Specs came from naval architects calculations, shipyard construction and measurement data, shipping company acceptance tests, some Navy measurements, all available, nicely bound and organized, with detailed construction plans, at:

Records of the US Maritime Commission Construction Division; Record Group 178, National Archives.

Records of the US Shipping Board Ship Construction Division; Record Group 32, National Archives.

There is a nice Regional Archive in Laguna Niguel, CA, just a few miles from my house. It has everything (or can get it in 2 days). People are very nice and helpful too.

Thanks a bunch. I know that facility. I've used it for some genealogy work. It's about 40 miles for me of pure LA/Orange County traffic, but I just might mosey on down there one things settle a bit with patches. IIRC, one of the problems I had there is getting microfilm reader time but sense these are books that would be irrelevant.

Buck

[JWE]

ORIGINAL: Buck Beach
Thanks a bunch. I know that facility. I've used it for some genealogy work. It's about 40 miles for me of pure LA/Orange County traffic, but I just might mosey on down there one things settle a bit with patches. IIRC, one of the problems I had there is getting microfilm reader time but sense these are books that would be irrelevant.

Buck

I'm sorry Buck, I guess I gave you a wrong impression. I was speaking hyperbolically when I wrote 'bound' and just meant to say everything is well organized. Didn't mean to imply books; it's on 'fiche'. They are working to put as much as they can on CD-ROM, but don't know how far along they are. Once again, apologies for causing confusion.

There is also a website, run by a German fellow, Frank Gerhardt, that goes into detail about the USMC from 1936 to 1950. He used to have extensive specs, by USMC Contract #, the link to which, I believe, is now broken. However, he is a very enthusiastic fellow who absolutely loves this stuff, and who I'm sure has the old data lurking somewhere. Shoot him a request and I'll bet he'll overwhelm your inbox.
http://www.usmaritimecommission.de/ is the site.
info@usmaritimecommission.de is for Frank.

Another good place is, of course, The Colton Company’s auxiliary site; http://www.shipbuildinghistory.com/ Tim Colton is another enthusiast who can direct you to where you need to go.

Norm Friedman’s book, US Amphib Ships and Craft, is also good. He, too, knows the difference between gross, measurement, displacement, and deadweight, tonnage. Small caveat, Navalized vessels had different specs after conversion, and Navy measurement of light displacement was different from commercial measure.

Last, but not least, since you are in California, SDSU has all of the late Dr. Alvin Coox’s personal papers in their library, including his complete, annotated, copy of Senshi Sosho, as well as all of the Monographs. If you have any Japanese at all, this is your Holy Grail.

Ciao. John

[JWE]

Hi Buck, Okay, just had my head reoriented by Brother Frank. Things are reorganized (damn, why didn’t I think of that). What ya do is go to the bottom of the opening page, to the “Special Sections” and click on “Drawings”. You’ll see all the designs, so click on maybe “The C2-Design” and scroll on down. You will see some of the different C2s built at various yards with a blue “Technical Specifications” bootawn. Click that and Hey!! Presto!! Some pretty serious tech specs!!

Frank thinks much like I do and gives specs on a specific design based on a building yard and a shipping company, depending on what he thinks is pretty. So a C2-S will have Bethlehem, Sparrows Point, as built for Robin Lines, numbers. Likewise, you have C3-Cs built by Federal, for Lykes, and C3-Cs built by Sun, for Moore-McCormack. He also has specs for some of the more pervasive Navalization conversions, and darn near all the C3-P & C As and Deltas.

Gotta be careful, because some ships have reefer capacity. This takes up much bale capacity and adds deadweight. I would suggest just passing reefer ships by.

Lots of holes, still, but he’s cranking along. Biggest hole is tankers, but I think the T2 Tanker page, and Auke Visser’s tanker page makes up for any deficiencies.

Hope this helps. If you have any further questions, I would be pleased to give you my best guess. Ciao. John

[Buck Beach]

ORIGINAL: JWE

Hi Buck, Okay, just had my head reoriented by Brother Frank. Things are reorganized (damn, why didn’t I think of that). What ya do is go to the bottom of the opening page, to the “Special Sections” and click on “Drawings”. You’ll see all the designs, so click on maybe “The C2-Design” and scroll on down. You will see some of the different C2s built at various yards with a blue “Technical Specifications” bootawn. Click that and Hey!! Presto!! Some pretty serious tech specs!!

Frank thinks much like I do and gives specs on a specific design based on a building yard and a shipping company, depending on what he thinks is pretty. So a C2-S will have Bethlehem, Sparrows Point, as built for Robin Lines, numbers. Likewise, you have C3-Cs built by Federal, for Lykes, and C3-Cs built by Sun, for Moore-McCormack. He also has specs for some of the more pervasive Navalization conversions, and darn near all the C3-P & C As and Deltas.

Gotta be careful, because some ships have reefer capacity. This takes up much bale capacity and adds deadweight. I would suggest just passing reefer ships by.

Lots of holes, still, but he’s cranking along. Biggest hole is tankers, but I think the T2 Tanker page, and Auke Visser’s tanker page makes up for any deficiencies.

Hope this helps. If you have any further questions, I would be pleased to give you my best guess. Ciao. John

John, What do you think about Thomas Wildenberg's book "Gray Steel and Black Oil-Fast Tankers and Replenishment at Sea in the U.S. Navy 1912-1992?

The entire book is at HyperWar: http://www.ibiblio.org/hyperwar/USN/GSBO/index.html.

I am really quite the novice here and I believe anything I read, hear or see. This sure looks like it has a tremendous amount of good information to build upon.

Buck

[JWE]

ORIGINAL: Buck Beach
John, What do you think about Thomas Wildenberg's book "Gray Steel and Black Oil-Fast Tankers and Replenishment at Sea in the U.S. Navy 1912-1992?

The entire book is at HyperWar: http://www.ibiblio.org/hyperwar/USN/GSBO/index.html.

I am really quite the novice here and I believe anything I read, hear or see. This sure looks like it has a tremendous amount of good information to build upon.

Buck

This is the first time I have looked at it. Thank you for the link, btw. I looked through it and the fellow seems to know what he's about. Some good stuff in there on T2s and T3s. Nice find. [:)]

[Buck Beach]

ORIGINAL: JWE

ORIGINAL: Buck Beach
John, What do you think about Thomas Wildenberg's book "Gray Steel and Black Oil-Fast Tankers and Replenishment at Sea in the U.S. Navy 1912-1992?

The entire book is at HyperWar: http://www.ibiblio.org/hyperwar/USN/GSBO/index.html.

I am really quite the novice here and I believe anything I read, hear or see. This sure looks like it has a tremendous amount of good information to build upon.

Buck

This is the first time I have looked at it. Thank you for the link, btw. I looked through it and the fellow seems to know what he's about. Some good stuff in there on T2s and T3s. Nice find. [:)]

Can't take the credit, some other fellow here on the board found it (relating to Chapter 17)/

Buck