Replacing the crush blocks, again
Today the shipwrights replaced the crush blocks at the keel for the third time. (Crush blocks are sacrificial soft wood pieces set on top of hard wood keel blocks which support most of the ship’s weight. As the hull settles, the crush blocks are pinched. They are removed with a chain saw and replaced.) A little over one inch of the hog has been eliminated by the force of gravity and the hull has started to shift in other places as demonstrated by laser measurement and visual evidence of narrowing gaps among the knees and deck planking in the interior of the vessel. The shipyard’s documentation crew has developed a progress chart of the hull’s movement. As depicted, one can see both a drop in the hog and gradual movement of the hull’s overall shape.
The challenge now is for the shipwrights to control the movement of the hull. To this end they are fitting the full with a series of moulds. These consist of oak planking bent and fastened to the hull in strategic locations positioned over heavy steel “I-beams.” Shores will be placed between the I-beams and the planking. These new moulds run port to starboard or crosswise to the planking. Morgan now has multiple support features: the newly installed moulds, metal stanchions, keel blocks and vertical wooden stanchions. When the hull settles to its desired shape (ie; proper sheer, reduced hogging and elimination of “racking” especially in the starboard bow), the shipwrights will halt the movement. They can then remove rotten planking and the ceiling and replace these with new materials thereby restoring the hull’s longitudinal strength and maintaining its shape.
A special note on the ceiling: three ceiling planks have been removed and are presently at the north end of the open red shed. These items have never been replaced and are yellow pine over 168 years old.
The first section of the shrink rack cover has been installed. Target date for completion of the full cover is mid-May.
The Morgan is the United States’ second oldest national historic nautical vessel landmark. The oldest is the USS Constitution which was built in 1797. Over 119 vessels have been designated national landmarks, mostly former naval ships.