1946 Chris Craft Brightside U22 Weak Bottom Frame Design Remedy

Yes, another update on the Brightside Chris-Craft U22’s bottom framing.

The bottom is framed with a combination of main and intermediate members. The main frames land on the main topside frames and are fastened with a plywood gusset in addition to the #10 x 3” wood screw through the chine frame.

These frames are spaced 28.5” on center, save for the final three, which are spaced 26.5”, 25.5” and 25” on center.

The intermediate frames a screwed to the chine frame and joined beneath the keel with a cross tie plank that is screwed through and into the face of each frame member.

John announced yesterday that all new frames were installed and positioned so that the keel just lands on every pair from bow to stern, “But we seem to have a problem. There are no intermediate frames in the three bays lying beneath and aft of the engine and transmission.”

Sure enough, as you see in the clip, these three bays, bays which must withstand the torque of the engine and slamming against the water at speed, are bereft of intermediate frames.

Inspecting the replaced chine framing indicated that Chris-Craft simply omitted these frame members from the design, a contention that was confirmed when RJ inspected the whit-side 1946 U22 we have in storage.

We contacted the owner, who agreed with our contention that fabricating and installing three pair of intermediate frames beneath and aft of the engine/transmission only makes good sense. So we will.

Doing so will significantly increase the stiffness and strength of the bottom and the hull, which should translate into more of the engine’s torque powering the prop, rather than tweaking the hull.

Yes, we will repeat this process with the white-side U22 when we get to her preservation.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.