Need help with the U1 limbe holes (slits)

[DrSchmidt]

I have question. It's about the limber holes in the deck structure of the U1. I've attached three photos for illustration. It seems that the limber holes were thin long horizontal cuts where the radius, that makes
the transition from the horizontal part of the saddle tanks to the vertical deck structure, ends. At the conning tower the cut is lower, due to the conning tower being so wide. I've marked the cuts in one photo with red lines.



Do you have an idea how to reproduce this with reasonable effort? Just making those cuts wold weaken the deck structure immensely. A series of bulkheads might help, but you'd need allot and it would be a ton of work.

[He Who Shall Not Be Named]

I have question. It's about the limber holes in the deck structure of the U1. I've attached three photos for illustration. It seems that the limber holes were thin long horizontal cuts where the radius, that makes
the transition from the horizontal part of the saddle tanks to the vertical deck structure, ends. At the conning tower the cut is lower, due to the conning tower being so wide. I've marked the cuts in one photo with red lines.



Do you have an idea how to reproduce this with reasonable effort? Just making those cuts wold weaken the deck structure immensely. A series of bulkheads might help, but you'd need allot and it would be a ton of work.

First, shave the inside of the hull under the eventual limber holes to render a wall thickness close to scale.





Then punch out the limber holes with drill and purpose modified jeweler's files.












Then strengthen between the closely space limber holes cords of carbon fiber thread CA'ed to the inside of the hull.

Done.

Sing my praises.

David

[DrSchmidt]

My concern is not the cutting...that I can accomplish. But the limber holes are not holes but slits that go along nearly the whole length of the deck. When I cut those, Ill disconnect the upper from the lower deck structure making everything very unstable. I can put in bulkheads to connect upper and lower halves, but the question was, if there is and easier way.

[He Who Shall Not Be Named]

My concern is not the cutting...that I can accomplish. But the limber holes are not holes but slits that go along nearly the whole length of the deck. When I cut those, Ill disconnect the upper from the lower deck structure making everything very unstable. I can put in bulkheads to connect upper and lower halves, but the question was, if there is and easier way.

The pictures were not illustrative of the geometry to me, can you sketch the geometry and placement of these slits and their proximity to one another? And by deck do you mean the horizontal 'main deck' one walks along, and lower deck the sides of the 'superstructure' supporting the deck?

Is the access break at deck level?

David

[DrSchmidt]

In the first attached picture of my initia post there are red lines....

I've also marked them in the second picture and attached it to this post.

[He Who Shall Not Be Named]

In the first attached picture of my initia post there are red lines....

I've also marked them in the second picture and attached it to this post.

Oh!... I see now. Longitudinal breaks (limber holes) that basically bisect the sides of the superstructure from the deck. Ouch!

Simple solution. layup a U-sectioned piece of channel, and bond it to the inside of the superstructure before you cut those long breaks (limber holes). That will maintain the structural integrity between deck and sides of the superstructure without need of transverse bulkheads or frames.

[DrSchmidt]

That's a good idea....nevertheless the slits will be challenging. On the photos (which have a bad resolution) they are very narrow, a few centimeters wide. Let's say they made it 5 cm wide - at 1/48 that leaves me with a 1 mm wide cut. I'll have to figure out how to make this accurately as well.

[He Who Shall Not Be Named]

That's a good idea....nevertheless the slits will be challenging. On the photos (which have a bad resolution) they are very narrow, a few centimeters wide. Let's say they made it 5 cm wide - at 1/48 that leaves me with a 1 mm wide cut. I'll have to figure out how to make this accurately as well.

Adjust the kerf width by layering thin Carbide cutting discs till the kerf equals the width of the limber hole. Use of a Machinist's gauge mounted rotary tool will insure a cut of uniform height and fidelity of line.

Install the U-section channels within the hull, then secure the hull to a flat surface, and run the cutting disc along the flat surface so that the Carbide wheel makes the desired cuts into the sides of the superstructure.

[redboat219]

Maybe you could try David's technique of replicating the missile break on a 1/96 Ohio class SSBN
https://youtu.be/2dDewXvqGWs?si=iglAp3ivhkWu1LQF

[DrSchmidt]

That's a good idea. Such a jig should be a quick fix...

[He Who Shall Not Be Named]

Maybe you could try David's technique of replicating the missile break on a 1/96 Ohio class SSBN
https://youtu.be/2dDewXvqGWs?si=iglAp3ivhkWu1LQF

Good catch, Romel. I almost forgot about those old, awful quality videos.

David

[redboat219]

Good catch, Romel. I almost forgot about those old, awful quality videos.

David

There are 5 more videos discussing this technique.