Thanks Chase, it looks like it was a good time! Some very cool pics. Do you know who owns the I-400? I have a question for him. J
I actually have some pictures of Frank's I400 I can post to. I talked to him about his sub on the last day, and got a lot of good ideas for my own sub hulls whenever I plan to actually work on them. I would really like to build my Surcouf for convoy next year.
Very cool, i will keep a copy of those pics for when i build mine, gonna have a different balast system though. I would love to talk to him but maybe one day i'll get to a Nats and see this stuff for myself J
I plan to partition the hull forward and aft and have a ballast tank at both ends. I will need to determine how big they need to be, gonna shot for neutral bouyant at about 2 ft, 3 at the most. It should be an interresting project. J
I was the sub's first target! Frank mezmerized me with the coolness, then SPUT! I had a hole. I was still in awe of the coolness after I was hit; good thing I-400 only has one gun!
There is a lot of info on the different ways to ballast your RC sub online in fact there are even companies who sell the entire systems now. (probably not small enough though) It shouldnt be to hard to find some info or ppl with expertise on how to make it work with being armed for any format of RC combat. They even have actual torpedos!!! its almost as cool as this obsession.
I don't think most of the traditional ways of balasting a sub will work in our scale. Those prefab tubes you see online that a lot of people use won't fit. We also can't use torpedoes in small gun (MWC, IRC & Treaty?). Frank's way of ballasting was pretty much how I was thinking it should be, though I hadn't thought of his way of doing the deck. I look forward to seeing J's sub build (as I believe, he actually served on one IIRC).
It all depends on which style of sub diving you want to use. There is Dynamic and Static. Dynamic means you ballast the sub so that the bow plans are below the surface already then the speed of the sub forces it under were static uses actual ballast tanks of some sort and there are a few different ways to do that the tubes being one of them. Im a big gunner and we use 1/4" cannons to simulate torpedos at close range. Does fast gun simulate at all or just ignore torpedos? No matter what you do a sub can be complex at all scales. Just build your stuffing tubes correctly. (i failed to build a good reliable one and it failed catastrophically. sub went down like a brick :/)
I think the conventional wisdom was that our subs can't go fast enough to use the dynamic method, but we probably won't know unless somebody who has tried it (if anybody) speaks up. I realise tubes are a method of sub construction, however I am saying that none of the ones currently produced would fit a 1/144 sub (yes, I'ved looked). Fast gun doesn't use torpedoes at all.
Spurt guns are supposed to simulate torpedoes. I have seen 2 other fast gun subs in person, both used dynamic diving, neither had a cannon. I think the diving planes were oversized, and there was a lot of problem with controlling the attitude of the sub underwater with the dynamic method. They tended to go nose down when diving and continue until they hit the bottom. Frank's diving method with a ballast tank is definitely superior, and he didn't have much trouble controlling it underwater. He did lose track of its position underwater at least once. I think if I did one I would probably put the access hatch on the bottom of the hull though, no deck rim to worry about or flex in the solid area there, and any leak might be less damaging. Ron Hunt
All the big gun subs that I have seen dive use dynamic diving. As I recall, they used oversize diving planes (twice the area shown on the plans, as per WWCC rules). I'm told that the earlier ones had to go over speed to dive as well, 33 knots I think (34 sec). The last one I saw dive used oversize planes, but was running at the allowed 25 knots (45 sec), and struggled to dive. I recall them running fairly stable about a foot below the surface at full speed, without "porpoising." I don't know how they managed that, since they weren't aware of, and didn't have space for, the electronics developed and offered for subs by places like Subtech. They had various numbers of single shot 1/4 inch "torpedo" cannons. Two had 2 forward tubes (I-400 and Type VIIC), one had 2 forward and 2 stern tubes (Surcouf, I never saw the stern tubes used), one had 4 forward tubes (I-401), and one had a single forward tube firing 4 balls (I-402). I-400, I-401, the Type VIIC, and Surcouf had a plunger mounted on the bow that would fire the cannons by bumping the target. A rubber disc was mounted on the plunger to spread the force over a larger area and prevent ram damage, so the only damage would be caused by the torpedoes themselves. I-402 is the only one able to remotely fire the cannon.
Yeah, I took the dimensions of some of those tubes and tried to make it fit into my I-400 hull, no go unless I decided to go without a gun, and either a receiver and a servo OR batteries. If one wanted to use those, a nice 1/72 scale model, like Ralph Coles ' Surcouf would be perfect. I think using tanks is the best way to go becuase with a dynamic diver, when speed is lost, the boat rises and speed is generally lost during a turn. My plan is a multiple shot spurt gun, Bob Pottle's idea, to simulate torpedoes. I actually served on 5 different subs, sailed on three, of two different designs J
