SELF RELIANCE'S first survey

On September 5, 1993, I examined the vessel, SELF RELIANCE, owned by Dr. Dave Weisher of 14314 Pleasant View, Bowie, M.D. 20720. The examination was made at the request of Mack Horton of Beaufort, NC, acting as agent for the owner.

The vessel seen was a 1983 CT 49 cutter, built by Ta Chaio Bros. Yachts of Taiwan; documentation number: 923800
The purpose of the examination was to clarify the extent of problems associated with a serious depression under the mast.
Examination was restricted to non-invasive means. All removable items were removed as necessary to provide access for investigation examination, but no destructive removal was used.

Observations and Findings:

The mast section is appropriate. The rigging wire is of sufficient size. The mast is keel stepped. It is located in the center of the main salon at the dinnette area. It is not adjacent to a bulkhead. There is a tierod.
The sole of the cabin was noted to have deflected 2" on a 6' span; there is also indication that the entire sole panel has sunk as well. There is opening of the joints of the joinery all around the area. The deck has been pulled down by the tierod.
The stays and shrouds were noted to be particularly overly tight. The type of mast support system is not unusual: There are three floors which are bridged with wood on which the mast is stepped. There was no adjacent athwartships reinforcement.
There was no broken bulkhead tabbing. The chainplate webs looked strong and sound. There was no hull deflection of the hull when the shrouds were pulled. There is no deformity of the hull in the area of the chainplates (as observable without hauling of the vessel).
There is notable deflection at the base of the mast when shrouds are pulled.
The vessel does not look as though it has been well kept over the term of it's life. There are indications of long term leaking, water damage etc... which were not attended to. The vessel was cosmetically scruffy for her age and has indications of neglect and some abuse.

History:

The vessel is very new to this owner and there was little known of her specific prior history other than those items and indications which could be gleaned from her condition.

Conclusions:

The design and engineering of the mast support system is obviously substandard. The calculations of mast compression loads were either inappropriate, or were not done at all and the general rules used in lieu of calculations were not followed.
In non-technical terms: The rig is large and generates very large compression loads. If the design of the mast compression bearing area is slightly under the ideal, and if the vessel has been especially stressed by overly tight rigging, there must be some relief of the force. As the hull/chainplate engineering was strong, and it has not deflected inward, the force was transmitted in a purely downward direction. This will have bent the wood bridge, compressed it and possibly deflected the hull in this area (this cannot be determined within the confines of in-water, non destructive examination) as well as having compressed and deflected the deck. Furthermore, as the load was not spread beyond the immediate bearing area, the compression load was higher per square inch.

Solutions:

The object must be to reduce the compression load per square inch so that the load is not greater than the carrying ability of the bearing area.+ This will require some redesign of the bearing area rather than a "repair" (via shoring up etc...).
Without being privy to the original design calculations, including the scantlings for the hull, one can only approximate the expected loads.
The most economical approach will be to spread the compression load over a longer bearing area.
Unstep the mast Remove the wood bridge Add at least one more floor fore and one more aft of the existing floors Fashion a fiberglass web fore & aft on the centerline between the floors Install limber holes as necessary to drain the area Fashion a box section bridge: metal fabrication: treat for oxidation or corrosion as approriate: with special care to inner surfaces Realign sole support/sole Restep mast and have the rig properly tuned. Repair joinery. Refair deck (optional).

Conclusions:

Anything less than complete engineered redesign of this area will be subject to failing again under the load. The surveyor has not been asked for the engineering specifications, but these could be supplied upon request.

The under signed surveyor has no personal or financial interest in the vessel herein mentioned.

Respecfully submitted without prejudice:

Graham S. Byrnes, N.A.
Surveyor
September 12, 1993

B & B Yacht Designs
202 ElmStreet
Vandemere,North Carolina 28587
(9l9) 745-4793