Rookie Ship Design Project, Part 2

Perhaps even develop low-cost, mass-produced, spring-powered torpedo launchers in modules that can be swapped quickly for reloading too (possibly with a means of firing individual torpedoes one at a time instead of unloading the entire battery).

 

Wouldn't springs be very rust prone? It also seems to me that you would need a pretty strong/heavy mechanism to release the spring at the right time.

1/4" rods would work very well for the spring torps though.

 

The spring could easily be kept oiled to handle the occasional dunking (or be made of stainless steel) and could be kept separate from the projectile by a piston; however, from just a brief bit of playing around with the idea and running a couple numbers, it would require a relatively heavy-duty mechanism to compress but release could be triggered with something as small as a piece of nitrinol wire. I have little doubt that in some if not most cases, there would be a slight delay from triggering to the time that the projectile would be released.

 

Yeah, that would be some SERIOUS "ram" bows!!

Corrected in original post.

JM

 

I believe most, if not all, use 1/4" ball bearings.

 

I did some work once on a spring-loaded 5-tube single-shot 1/4" ball bearing torpedo launcher. I got the springs right, as far as speed/penetrating power is concerned. The biggest trouble was reloading, & it was a HUGE problem. All that force was very difficult to overcome, even on a bench version. I rigged up a 5-pinned loader with a handle, to simultaneously push the balls back until they seated behind the latch. The force needed was too much to be practical, especially on a small ship. While I could physically do it, I had to be able to apply equal or greater force in the opposite direction, or brace against some very solid object. That didn't seem very practical when mounted to a ship.

Releasing was no big trick. Each barrel had a pivoting latch, with all of them attached together with a crossbar. Here's the basic design:



JM

 

That looks like a simple yet devastating weapon. The rearm force is a major problem though. You would have to have a VERY sturdy ship.

 

There's also the option of swapping out pre-loaded assemblies or simply be able to easily disconnect the entire assembly in a safe manner for reloading.

 

I think that a quick replace for the whole unit would be quicker and easier. Make sure the trigger solenoid was attached as part of the unit and just a simple plug connector should suffice.

 

Have you considered using a large C-clamp for reloading? One end would push the ball and ramrod down the barrel, and the other end would push against the back of the cannon, to take care of your "equal and opposite" force. However, I do have a few other concerns. first, how would you "safe" the cannon? And second, how would you prevent the cannon from firing "on the upward roll"? All the torpedo-cruisers that I have seen have a noticeable down-angle on their torpedo tubes. This down-angle isn't just to score below-the-waterline hits, it's to prevent the cannon from aiming above horizontal when the ship rocks and rolls. I remember one ship built with perfectly horizontal barrels. It fired once and sent balls flying over everyone's heads. After that, the skipper bent the barrels for more down angle.

...wait a second, why are we discussing this? We're a little off topic. Last I remember, we were trying to decide which ship to model. Armament is only part of the decision to be made. Back on topic, I vote for the Le Fantasque. It's big and fast, and has single-barrel turrets. You can arm either a BC o-ring cannon or a set of torpedoes. Plus the plans are available for free online.

Has anyone seen the 1:125 Lindberg Fletcher? It's not a perfectly accurate hull. The kit designers squared off the bottom and sides. This improved stability and displacement, and actually looks pretty good. It also makes for easier baseboard-style construction. Do you think we could do similar on our own project?

 

I don't see any reason we couldn't. For a destroyer, we're already going to definitely need to add the maximum extra allowable displacement to have any reasonable hope of fitting everything in; flattening out the bottom of the hull should ease that and I'm in no hurry to repeat the intensity of the cursory resurfacing that I found to be necessary on the Emile Bertin just to be able to develop a clean blend (to say nothing of tangency) on the bottom of the hull that would allow me to safely sew the sheet body surfaces into a solid. After I get done with some basic drawings for the Emile Bertin superstructure, I should be able to get started on the hull of whichever ship we do decide upon here (assuming that I have access to the necessary drawings at that particular point in time). With the le Fantasque (or any of its class sisters for that matter), I wonder if we would be able to cram a single fast gun-style cannon (perhaps with only 25 rounds) with rotation into the hull along with two banks of twin-barrel single-shot torpedoes. If we could get anywhere remotely close to that armament option, I'd have to wholeheartedly go with the le Fantasque.

 

No, but I don't have one that I'd expect would fit. Also, it's pretty necessary to load all at once since they have a common trigger. Both issues might be solvable, though.

Definitely a valid concern. I hadn't gotten that far into it. I just wanted to see if I could make it "work" in the 1st place.

No reason it couldn't be aimed downward.

Right, it really ought to be in "Weapons".

JM

 

Tugboat, you've got a good point about having ships from different navies. Perhaps we should start with the smallest 1.5-unit DD, and develop a standard "guts" package to go with it. Then draw up the hulls for the other ships. With that in mind, I don't think the Le fantasque is the best choice. Maybe a Z-boat? How do the 1.5-unit destroyers compare?

As for armament, I think we need to define a few terms about torpedoes and cannons. I know Fast Gunners are used to single-shot vs spurt cannons, but for Big Gun there are additional terms you need to know.
1) reloading vs non-reloading: A reloading torpedo cannon is a torpedo cannon that automatically reloads, just like any other cannon. This requires an onboard magazine and an onboard air source. A non-reloading torpedo cannon is a torpedo cannon which must be manually reloaded by the skipper, on shore. This generally means no onboard magazine and no onboard air.
2) single-tap vs double-tap: A single-tap torpedo fires one ball per barrel, just like any other cannon. A double-tap torpedo fires two balls per barrel. As they say in the British navy, "double-tap and fire on the downward roll!"

With this in mind, Webwookie, when you say "single-shot", are you hoping for single-tap (but still reloading) torpedoes, or non-reloading torpedoes?

 

I hadn't thought of it at the time, but I'd say single-tap, non-reloading torpedoes and a single fast-gun (interrupter piston type) cannon would make for a good design goal. I figure the standard guts (for a weapons package) could be divided into gas system, bb cannon, and torpedo cannon "modules" that can be interchanged between destroyer classes.

 

I just looked at the MWC shiplist, to see which 1.5-unit destroyer is the smallest. Apparently, it's the Gearing, at 2.61 lbs scale weight. Then comes two small frenchies, Z-35, and a "Narvik" Z-boat, followed by the Shimakaze, The Akizuke and Le Fantasque, Mogador, and Tashkent. If you consider Abdiel to be a destroyer instead of a minelayer, then it comes in between Le Fantasque and Mogador.

With that in mind, I would suggest that we start with the Gearing. After that we can do the Z-boat, Shimakaze, Le Fantasque, Mogador, Abdiel, and Tashkent. I am figuring it's easier to start with the smallest first, and then add extra features as we gain additional displacement. Armament-wise, I'm thinking it would be great if we could do two 1/2-unit cannons, with the option of torpedoes. The reason I suggest two 1/2-unit cannons instead of one 1-unit cannon is because it's (relatively) easy to switch from two cannons to one, if you so desire, but not so easy to switch from one cannon to two. And that way you have the choice of a one-unit cannon forward or aft, two 1/2-unit cannons split forward and aft, or two 1/2-unit cannons paired forward or aft.

After the primary cannons are taken care of, we can think about adding in torpedoes and other weaponry. Personally, I wouldn't hope too much for both cannons AND torpedoes in a Gearing. It's worth a shot, but by no means guaranteed. We're much more likely to succeed with some of the larger destroyers, though.

 

Starting with the smallest and moving up is a perfectly valid strategy. (It'll also open up the field with some non-French ships.) By figuring out how to make it feasible to mount a pair of fast-gun cannon, it might be motivation for some rule sets to permit split units on 1/1.5 unit combat ships to further encourage their use.

I figure that for the Gearing, it may be an either/or with regards to arming cannon and torpedoes but the idea of at least seeing if we can arm two cannon in a Gearing (fixed or otherwise) is definitely a goal worth pursuing.

I think that we should have main cannons designed first, followed by torpedoes (since the former is compatible across formats). Kotori, any idea on how light we might be able to get a bb or piston-interrupter cannon with a 25-rd magazine with COTS parts (modified of course)?

Other thoughts?

 

I'm not sure how light we could make a piston-interrupter cannon. I was mostly assuming that we would go with standard BC cannons. I figured that since we're designing rookie ships, we might as well try to get quality cannons for rookies. Torpedo cannons would have to be custom-made, but I see no reason why we can't use standard cannons for the primaries. Besides, I've seen some people cram in some very overkill stuff (KIPS solenoids, SLA batteries, geared 500-size motors, etc) into their itty-bitty destroyers. I'd bet that if we just pick our components and materials more intelligently, we could save a lot of weight right there.

I've scanned a set of plans for the Gearing, that are pretty nice. The superstructure is a bit off, but the hull and cross-sections are great. Send me a PM and I'll email it to you. Also, I've spent some time studying the squared-off hull of the Lindberg fletcher, and figuring out how they did it. I can write up a description of how to square off each of the ribs, if you're interested.