【Safety】 If hull and upper frame separate on a single scull?

Hi there !

To all loving rowing and sculling.

I experienced very rare case on a single scull.
In these days, single sculls of monocock structure are popular for competitors.
In our club, members gather every Saturday and enjoy rowing or sculling.
Our single scull is conventional structure and is composed of wooden frame and composite material of hull.

This story is about what happened if frame and hull are separated, broken adhesive part.

I sculled one of single scull（called S7）of my club for 2 days consecutive.
While sculling this skiff, I feel fear of starboard blade to deepen after catch and rolling movement toward starboard side.

On 2nd day, my colleague found separation between upper deck with splash guard and lateral hull on starboard side, when I reached dock and I remained on this single scull S7.

Please refer to the photo in the following subscription about where and how the breakage, that is starboard lateral hull separates from upper frame with splash guard.

https://1xer-novice.blogspot.com/2019/05/blog-post_54.html

I have just got assumption that breakage, separation of upper deck and lateral hull is cause to deepen starboard blade at catch.

Weak stiffness due to shell breakage

The reason why bendig deformation gets greater is sectional moment of inertia of separated section reduces very much as you can find.

Some colleague denied this breakage is cause of deepen blade, and he measured row lock pin inclination. And he confirmed inclination was normal.

It took 6 weeks to repair this separation completely. After repair, that is bonding upper frame and lateral hull, I have to try repaired single scull S7.

As I expected, I can not feel any fear of deeping starboard oar blade nor any rolling. While I tried sculling S7 for 10km after repair, I could not feel any deeping of oar blade.

Conclusion:

If lateral hull separates from upper frame with splush guard, single scull shell is bending due to weak stiffness. This bending inclines rowlock pin foward, then it brings deeping oar blade.

Fortunately my colleague found this separation. But no one could find it and we cotinue to use the single scull, how long will separation increase and what will happen to the scull finally?

Today almost single scull are monocock structure, but many single sculls of conventional structure, composite hull and wooden frame are bonded with adhesive.
After long usage, repeated load of rowing breaks this bonded section, especially the part with fore splash guard.

This breakage is proven while it is on water and crew is sitting on it.

I hope my this rare experience will be useful to someone.

Over
1xer-novice