The Ship Model Forum

I only mention the Barbel class as an example as I've seen the misconception before that five-bladed propellers always are unskewed. The blade shapes of skewed submarine propellers designed by BuShips during that era were all very similar whether the propellers had five blades or seven. Based on a single photo that only shows two blades, I am guessing that the Tullibee had a five-bladed skewed propeller, but I do not know for sure. Consider that the Tullibee had similar power (2,500 SHP) and speed (16 knots) as a diesel boat, and the propeller diameter (12'9") was similar to that of the Barbel (12'6").

Here's a nice photo of the Barbel propeller:

https://upload.wikimedia.org/wikipedia/commons/c/c6/SS_Blueback_Propeller.jpg

Originally the Tullibee had a five-bladed unskewed propeller, but so did the Thresher. Here's a document with some drawings of those original propellers:

https://dome.mit.edu/handle/1721.3/48952

This document has a drawing of the Sargo's skewed propeller, which gives some idea of the skewed blade shape of that era.

https://dome.mit.edu/handle/1721.3/49068?show=full

Jacob

Mike, It would look like this photo posted. This is Barbel with the 5 bladed skew back. I am 99% sure that Jacob was the one who found this photo, among others.

Sometime in the late 1970's, Tullibee suffered a serious casualty in which her propeller shaft fractured, dropping the screw. Fortunately, the break was outside the shaft seal; otherwise it is virtually certain she would have been lost to uncontrollable flooding.

CC- the drawing of Wiswesser Tullibee is way off. If you measure the length to beam ration of the drawing (I have it, so I did), it comes out to roughly 8.06. Tullibee's actual length to beam is 11.56. So the Wiswesser drawing shows the hull as either too short, or the beam too wide. Also, the original, visible PUFFS were both larger than depicted. The very large 3 PUFFS were, I believe, from a 1970's refit.

The low power S1C reactor meant her top submerged speed was under 15 knots.

Wait, what's this about a 5-blade skewback for the Tullibee? Similar to Barbel class?

Ah, the Edward Wiswesser drawings. Unfortunately his drawings only bear a vague resemblance to the real ships; he seems to have drawn his plans entirely by eye without any references below the waterline.

Jacob

Found two drawings in my index that might be helpful:





These look to have been drawn prior to the extended PUFFs array install. The overall shape is pretty simple and easy to 3D model.

c3

Tom,

The Tullibee facebook group allowed me to join because of my historical interest and there are some drydock photos which show the long-chord stern stabilizers. But since it's a private group I'm not sure that I should share them publicly. They are not particularly revealing shots anyway.

I don't remember the source of the drawing; it looks like it's from a magazine/journal or something based on the caption. A very similar drawing sans reactor is in the Welcome Aboard pamphlet on Navsource.

As for the propeller, that photo you posted is actually of the Dolphin. Someone mis-captioned that photo as being of the Tullibee a while ago. There is a photo which shows a two blades of the propeller on the facebook group and the spacing to me is suggestive of a five-bladed propeller vs. a seven-bladed one. Regardless of the number of blades it was a skewed propeller.

Jacob

Thanks, Jacob! Where is this drawing from, as well as the information confirming the long stern plane chord? Finding information on Tullibee is even harder than some other "one offs" such as Triton and Halibut. At least there are decent drawings of both of those available.

The (poor resolution) photo I posted above shows Tullibee in dry dock and she has at that point in time (unknown), a 7 bladed skewed propeller. That would make sense since the was engineered with the turbo-electric drive to ascertain if that propulsion arrangement reduced the overall acoustic signature. the skewed 7 blade would reduce the low frequency blade rate component of the sound signature.

I am not aware of any reasonable photos of Tullibee in dry dock, despite the fact that she spent a lot of time in overhaul. At one point, Tullibee's propeller shaft broke and dropped the propeller. Fortunately the break was external to the shaft seal so she wasn't lost.

Probably the best Tullibee drawing I have seen in the public sphere is this one:

https://i.imgur.com/xO4eFDI.jpeg

The bow shape should be pretty accurate. Note the extremely long chord of the stern planes (which she did have; it's not an artifact of this particular drawing). This is a feature I don't think I have seen in any model made of her. I also have a suspicion that she had a five-bladed, skewed propeller, similar to that of the Barbels, but I haven't been able to confirm that.

Tom, here's a fun trivia fact: there were actually four PUFFS hydrophones originally. Two in visible domes, one under the superstructure like you said, and one in the leading edge of the sail. The Thresher had the same BQG-1 system originally, although in her case 3/4 of the hydrophones were on retractable masts.

Jacob

Mike, The drawings look really good and I think reflect the correct bow shape for Tullibee. See the photo of Tullibee prior to launch. Tullibee pioneered the placement of the spherical sonar dome in the bow and the torpedo tubes angled out further back. I am not sure that the stern shape of the Mikromir kit is correct; I think it tapers too gradually. See poor resolution dry dock shot. The Tullibee had turbo-electric drive (as well as the only submarine with the S2C reactor) and may have needed more room aft for the big DC motor. The Glenard Lipscomb was another try at a DC turbo-electric drive and used a considerably lengthened Sturgeon hull to accommodate that set up. The concept behind turbo-electric drive was it was one potential solution to noise generation by the propulsion plant. Tullibee was slow, as the combination S2C with steam turbogenerators and DC drive yielded only 2500 SHP (in comparison, the S5W steam turbine plant was 15,000 SHP).

Tullibee was not particularly successful, not altogether surprising in an engineering prototype with so many new features. She spent so much time at Electric Boat that she was known as Building 597. The decision was made not to make dedicated SSKNs like Tullibee, but instead incorporate many features (bow sonar, angled torpedoes) into the more conventionally powered Thresher/Permit class. To reduce radiated noise, the 593 submarines featured rafted decks for the steam propulsion train.

The model is the Yankee ModelWorks version of Tullibee in resin. I used the "as built" smaller PUFFS on this rendition. This shows both the bow hemisphere and tapered stern, as well as the curved shape of the aft superstructure deck

Tullibee originally had 3 smaller PUFFS sonar installations, with one under the aft superstructure deck. It was later refitted with the much larger PUFFS "fins". The forward fin appears to be roughly the same height as the sail (see photos, which I have reduced in size to (maybe) fit the size limit. Last time I tried to post these the entire message disappeared. Also the second shot large PUFFS shows how close the rudder is to the rear deck, again suggesting a sharper stern taper.

I don't have an accurate set of calipers, but if someone else does, Tullibee's measurements were:
272' 9.5" length
23' 4" beam

Tom

EDIT: Geez, it posted!! The FIFTH time was the charm...

NM. Thought you were trying to get into the album I posted and that I had goofed something up.

Logged in, tried to post materials but nothing happens.

Tom

I definitely would be interested in 1 or 2 sets.
Might as well do an early and late Tullibee.

I finally started messing with the Tullibee bow shape last night. This is a pretty casual workup, I took some quick dimensions from the Mikro-Mir kit for hull diameter and for the distance between the leading edge of the bow and the split line I'm aiming for. I'll get a better number for that split distance when I actually remove the bow. Anyhow, have a look at what I've drawn up. Went off the "more spherical than elliptical" description and the leading edge is very much a sphere connected to the hull diameter very a tanget spline. But would love to hear some feedback. Also, if anyone has calipers handy, would love to see some outer diameter numbers along the extruded length of the hull. I measured 20.3 mm (with some '+' variance) last night though I think it should be 20.5 mm.

Also, anyone have any good closeups of PUFFS? Like the really big ones seen on Tullibee? Might redraw those too.

Link to album:

https://photos.app.goo.gl/3nLbaEuwDKDeAkkN7

I like trying insane stuff. You should see what I am doing to the Mikromir PAPA.

I'd still buy one off of Mike since I would likely decide that I need to move on to other projects at some point.

Dave

Mike,
Well I will certainly buy a new bow section. I was looking at the MikroMir Tullibee and wondering what to do with it. Since I finished the resin kit from YKM as the early outfitting, I would love to do the later version with larger PUFFS and 7 blades. But I was just shaking my head at the wrong shape of the bow. Sure, I could try to fix it, but it would be a real task to get it correct, and I have so many other kits waiting to be assembled.

I will send you a separate email, as I need a few more propellers as well as I want to know if you still produce the 1/350 Regulus missiles. I need a set for Halibut, and I don't particularly care for the thin photo etch wings on the ones that come with the kit.

Tom

No, no longer! Someone purchased one in August!

The time to sketch this out will be small. I looked at it some more last night as I was sanding the seam line on the hull. There's the natural scribe line for the bow on the kit and that would be my chopping point. Then it's just a matter of agreeing what the shape should be as the CAD time won't be that long. As for price point, yeah, I think I can easily hit that. Easily. As for # of buyers...no concerns there inasmuch as I'm doing it for myself first and foremost. So if anyone else wants one, great!

That’s an intricate task, getting it symmetrical and properly shaped.

Actually, the easiest fix would be a 3D printed bow replacement piece. The forward hull basically abruptly transitions to a a hemisphere shape rather than the elliptical bow taper as on the MikroMir kit. The question would be is it economically worthwhile for someone to spend the time designing it? And would individuals be willing to pay, say $15-20 for a replacement bow piece?

Keep in mind that the majority of the crazed submarine model builders are those of us on this board… The potential numbers of buyers are small

They probably kept the same diameter for the Tullibee's seven-bladed propeller. The max RPM was 200, like pretty much all submarines of that generation, so you wouldn't necessarily have the issue of blade tips being too fast. But you couldn't make the propeller boss any larger in diameter, and it might actually lead to a decrease in efficiency because you are operating more outside the wake of the very slim hull of the Tullibee.

Jacob

Am I still the only other owner of an Ula?

I have to agree that Mike's screws are awesome. I have a pile of theme for various projects. Looks beautiful on my model of my first boat... Shockingly SSN 705...

I'm probably crazy enough to try to fix at least the bow of the Mikromir Tullibee.

Dave