Wieght Conversions.

I am going to begin making an LST-542 class landing ship soon. But before I begin, I would like to know how to convert the ships wieght (1625 tons light, and 4080 tons full) into the maximum wieght allowed in a 1/144 scale IRCWCC model. Any help is welcome, and if you are one of the few gifted with true mathmatics skills, I need your help. Thank you.

 

I'll see if I can find the formula and post it to you. As a general rule of thumb, it works out to ABOUT (not exactly) 1000 tons = 1 pound. So, you'll end up in the general neighborhood of 2 pounds.

The question I'd ask, is what are you going to do with an LST?

 

thanks crzyhawk, i saw something on the site about English Tons (2240 lbs). and the LST is going to be a purely personal ship to start into the hobby. It will be simple and easy, and I hope for it to be a precursor to a larger ship (i am looking at either a Richelieu or an Alaska). It most likely wont battle, and if it does, it will be on more of an informal basis. It will be a quick, inexpensive learning experience. I will, hopefully, start as soon as Tugboat gets the plans on the file manager. And if i can, i will go with 4 lbs(full load, and i thought i heard something about a certain percentage allowance with wieght, if you know anything about that). Thank you, Boomer

 

Hey Tug, hope my emails arent bothering you. I am looking forward to those plans though, let me tell you. I got up at 5 AM too, my little brother needed babysitting.

 

I'm really having a hard time finding the post with the formula in it. I can't remember if the discussion was on this site or on the IRCWCC email list before I left it. I remember the discussion was about the weight of a Baltimore class ship's allowed displacement. Powdermonkey might remember where that discussion is better then I do.

With the displacement, full load doesn't count. Only the STANDARD displacement counts, but you get to add 10% to it. There's a formula to calculate the displacement (it may be in the IRCWCC rules, I can't remember).

As for a learning experience I understand the idea, but not really the reasoning. I'm not trying to say don't do it, just trying to say I'd give a lot of thought to the benefits of doing it the way you are, because in my opinion there really is no benefit to you.

The LST is not going to be a simple build like you think. You don't get much weight to work with, and fitting everything in is going to be a hassle. To get that small, you're probably going to need to go with very lightweight batteries such as li-po's that the airplane guys use, but they are PRICEY. You'll probably have to use higher quality motors then most of us tend to because of the batteries...that's going to raise cost as well. Micro servos are more expensive then the regular sized servos most people use. If you get everything to fit in there, then you have the prospect of never being able to BATTLE with it, because you can't decide to add guns later, you simply start over with another ship. Since the IRCWCC very rarely does convoy battles (once per year or so), I believe there's just not much value to you, and the ship will be a difficult and expensive build for basically no gain.

Something else to think about is the wind effect. At 34 seconds and with almost no draft, you'll get blown around a lot if the wind gets up a little bit.

That's why I'd highly recommend doing a warship of some variety first; even an un-armed one. Most warships are significantly heavier (I'd recommend against things like Destroyers for the same weight reasons) which gives new guys a little room for error. Plus, you have the added value of being able to add weapons to it at a later time and get some enjoyment out of it.

That being said, if I were you and looking for something small, I'd give some thought to the Atlanta from BC. She's got a simple hull shape which will make sheeting easy, and off the top of my head has about 8-9 pounds to work with. You can build her unarmed at first, and still run around the pond at 23 seconds and be faster then everything else out there. The LST would be 34 seconds and be SLOWER then everything else out there...even the dreadnoughts would easily be able to chase you down and pound you...and you wont have a pump. As you get more time, you can always add a gun to the Atlanta (or whatever warship you built) so there is some room for growth with your first project.

So in conclusion, I'd like to say I'm not trying to talk you out of the LST. I look at it as my duty to try and point out some of the potential pitfalls with any given course of action so you can make the best informed decision possible. It would really suck for you or anyone else to build something, then end up saying "man, I wish I would have thought of before I built this thing." when someone could have warned you in advance.

 

I have been warned, many times. i know. But for me, the cost of a larger ship is too much right now, and i dont have a ton of room. I might look into the Atlanta classor even (GASP!) the Cleveland class. Im not 100% sure right now, but im hoping to make it simple. Thanks

 

Oh I don't blame you for wanting to stay small and cheap. I was 15 once too, and this hobby is well beyond anything I could afford. Hidden costs that you wouldn't expect are out there though. Take for example batteries. With your LST, you'd need to look at going as light as possible...and right now that's li-Po. I'm familiar with them because I have some friends who are into RC planes at the moment, and they just dropped 75 bucks per battery for 8 minutes of flight time. I kid you not, here is a link to some comparable batteries:

http://www.hobby-lobby.com/kokam.htm

Now say you go with a Cleveland, you now have like 12 pounds to work with and can start to think about a 7 amp hour SLA battery. At 3 pounds it won't fit in your LST, but will fit easily into a Cleveland.

http://www.batterymart.com/p-6v-7ah-sealed-lead-acid-battery.html

At $12.95 it's a LOT more cost efficient for you, and will last you a longer on the water.

Then there's servos. The micro servos you'd need for your LST are costing my buddies $15.00 each for their airplanes. The servos I run in my ships are $10 each. An unarmed LST will probably need 2 servos; one for throttle, one for the rudder (a MAG throttle will cost you less money to make then will an ESC) An unarmed Cleveland will have the same two servos...but at 5 dollars less per servo, you can afford 1 more for the same price (to eventually drive guns!).

Given that price is an issue, I think that a Cleveland (or one of the plethora of Brooklyn derivatives) would be better to look at then an Atlanta, because of the weight. With an Atlanta you'd probably have to look at using lighter batteries, and the only real reason to build that over another ship is the extra speed it gets as a class 2 ship.

You could always look at scratch building the hull as well to save a few bucks, if you don't want to just order from BC. It (the Cleveland/Brooklyn/Wichita/St.Louis/Fargo hull...the USN got a lot of mileage out of that basic design!) is a pretty simple design with relatively slab sides and a fairly flat bottom which should be one of the easier scratch build warship hulls out there.

 

The more you talk about it, the more i like the sound of a cleveland. This might make monk angry[}]. ha ha

 

The conversion is LT/1333=lb.
Max allowable weight for IRCWCC and MWC is the heavy weight + 10%. For class 2 and below, it is +25% or an extra 1 lb. whichever is more. This does lead to the unusual circumstance where the max scale weight of Yamato in 59lb. while Shinano is 74lb. Maybe I'll fix that next year.

 

I don't think you'll need to add much of any weight to it to get it to waterline I have a friend who built one for Big Guns... and he had to use lots of weight saving tips.

I think the LST's are on the large side of the "really small" transports. Should be a fun challenge

Mike

 

Thanks for the formula. That puts the LST at 1.22 lbs for regular wieght, and at 3.06 lbs for maximum wieght.

 

Mark, quick question. Under IRCWCC rules, it states the Cleveland as a heavy cruiser, but many other sources state it to be a light cruiser. Because of its size, the units dont change, but it would be 1 second faster as a light cruiser. Any idea about whats up with that?

*****(EDIT*- the ircwcc lists the cleveland as having 12 6" guns. And if you look at the light cruiser page in wikipedia, it states that the 1930 London Naval treaty defined light cruisers as "cruisers having guns of 6.1 inch (155 mm) or smaller, with heavy cruisers defined as cruisers having guns of up to 8 inch (203 mm)"). see my issue? Thanks for any help regarding this mess.*)*****

 

This link is more help to those of the Big Gun variety (since IRCWCC and MWC have it in a hard coded table), but it is a formula to calculate the weight of the model to get it approximately to the waterline:
http://rcwarships.org/rcwarships/nwc_new/?category_id=27&menuaction=phpbrain.uikb.view_article&art_id=41

Cheers
Jeff

 

For legal purposes in the treaty era (one of the London treaties actually, the Washington treaty simply limited cruiser caliber to 8 inches or less), a heavy cruiser was designated as a ship bearing guns of greater then 6.1 inches (155mm) and a light cruiser one with guns of 6.1 inches or less.

This is shown in the ORIGINAL designation of the American treaty cruisers (Pensacola and Northampton classes) which carried 8 inch guns and were labeled as light cruisers and carried CL designations. When the first London treaty came along and created a distinction between heavies and lights, these 8 inch cruisers were re-designated as Heavy Cruisers and given a CA designation.

The original intent of the treaty was to cap the number of 8 inch cruisers, and force the signatory nations to build more, smaller cruisers. At least that's what the Brits wanted, and laid down their Leander class ships with 8 6-inch guns. What the British failed to do however is cap the displacement of these light cruisers (a lesson they learned for Second London), and the US and Japan built up to the 10k ton limit with their Brooklyn and Mogami class ships each with 15 6-inch and 6.1 inch guns respectively. Obviously the British ships were outclassed and they laid down the 10k ton Town class with 12 6-inch guns.

Heavy and Light crusiers was the official USN designation of 8 and 6 inch armed ships. The British called them simply 8-inch cruisers and 6-inch cruisers. The Japanese called them Class A cruisers and class B cruisers. The big, 10k ton CLs were light cruisers in name only; they were every bit the equal and often the superior of the "heavy cruisers".

What's all that mean to you? basically, don't follow the "official" designation. What's important is the units. For IRCWCC purposes displacement determines units, and thus "class". A class 3 cruiser is 24 seconds (regardless of it's main battery caliber) and a class 2 cruiser is 23 seconds.

At 10k tons standard, a Cleveland is a class 3 cruiser with 3.0 units. That makes it 24 seconds, regardless of it's main battery caliber.

 

thanks for clearing that up for me mike. I understand better now. Im still interested in the cleveland, im thinking that, spread out over time, i can afford it.

 

That's the way to do it man, regardless of what ship you build. You don't need to be able to do the whole thing at once to do make progress.

For example, once you get the hull (regardless of whether it's a LST or a Yamato class BB) you can sand it, and cut the windows without spending any more money. If you have plans, you can cut the holes for the shafts and drill a hole for the rudder.

That's a lot before you have to spend another dime. Then, when you get some more money, you can get some wood and epoxy and start working on things like the subdeck, main deck and water channel, perhaps the super structure.

Using that as a plan you can spend bits of money here and there, and spread the cost of the ship over the amount of time it takes you to get the work done.

As far as total cost, I firmly believe that a class 3 cruiser is about as cheap as it gets in the long run, mainly due to size. It's about the simplest type of ship you can build and still use full size servos, SLA batteries, and simpler CO2 system with fewer guns. Anything smaller then that, and you really have to start looking at NiHM or Li-Po batteries which are much more expensive due to weight.

Something else to think about, is that the basic Cleveland hull can also be used to build Brooklyn, St Louis, Wichita and Fargo class ships as well. So if you don't like the way the Cleveland looks, or perhaps the battle histories (if you're into that kind of thing) or names, perhaps one of the other classes which use the same hull would be good options.

My favorite use of that hull would be the USS Helena, a St Louis class cruiser which was very active in the early Solomon campaign. I'm really into the histories of the ships.

Wichita is actually a 8-inch heavy cruiser and very cool looking. If you just care about looking cool, check out the Fargo class ships. They're probably the coolest looking cruisers ever built IMHO (read it and weep, Prinz Eugen fans)

 

For this, im (most likely) going to buy most of my stuff from BC, thats why the cleveland, but i know i can change it to others on the same hull, but i really do like clevelands. And you have to sand a fiberglass hull? With what grit? And i know about cutting the windows, but how much do you have to leave on top of the hull intact (like when you go to put on the tape to mark up the windows, the bottom is the 1 inch, then 45 degree rule, and i know about the ribs only 3/8 inch and 1 inch between, but what about the top? And im thinking of buying the Hull kit, the deck kit and maybe the hardware kit at first, then waiting for more money for the rest. I cant wait to get started now. but the build will begin about a month after my birthday in mid-august(big influx of money then, due to a large family [], so then ill order it, and then wait). So, well see how that goes.

 

Yes, you'll have to sand it down, inside and out. As for grit, I used fairly fine sandpaper on my invincible; I am not sure that was the best way to go. The bottom line is, you want to sand until all the shiny areas are gone. If you don't the adhesives you'll use won't stick properly.

As for cutting the windows, IIRC, (you'll have to check the rules because I don't know off the top of my head) the window has to go to the bottom of the subdeck (so something like 3/8 of an inch from the top of the hull).

Some guys cut windows first, others like to wait until they have laid everything out so they float the ship, mark the waterline, and cut their windows based on their actual waterline. Otherguys use the scale waterline and measure down one inch from there, then try to make sure they float at the scale waterline.

As for the ribs, the MAX size they can be is 3/8", and the MINIMUM spacing is 1". You'll probably have more then 1 inch between ribs. Some guys use 1/4" ribs. The difference is you can have MORE 1/4" ribs then 3/8" ribs. The bottom line is, you have to get to 85% penetrable after your bow and stern hard areas. On my Invincible, I have a combination of 3/8 and 1/4 ribs, alternating.

One of the guys in the IRCWCC used to have a rib calculator program that you put some information in, and it would spit out the number of ribs. I may still have a copy that he sent me at home; if I remember tonight I'll plug Cleveland numbers into it and post the number of ribs/size etc for you.

Have you decided which of the Cleveland class ships you wish to build? Some of them have pretty interesting histories. My personal favorite of the class is the USS Columbia.

 

Awww, i like shiny[V]. Ok, that doesnt sound too bad, and i get the premise of the sanding. I dont know which way is better, but i think, because of the amount of time between purchases, that ill be cutting out the windows in the beginning. Yea, if you have it, i would love to find out, it would be a huge help, im getting excited, even though i know its a bit off in the future. Im not going on history for this one, because the name USS Biloxi is available as a name. I went to biloxi this spring and helped rebuild one man's house from the (still exist and wide spread) hurricane/flood damage. It was extremely rewarding, I love the city, and the ship was every where in the pacific theater and even survived a kamikaze. So i like the history, but its the name that does it for me.