Fastenings

In 1894 Effie M. Morrissey was fastened with trunnels and iron. Iron and wood served again when Ernestina was prepared for her return to Massachusetts in 1982.

The center of this piece of African hardwood has been degraded by a rusting iron fastening but the peg carved of the same wood is still sound.

The current rehabilitation of Ernestina-Morrissey is using the traditional locust trunnels and corrosion resistant silicon-bronze fastenings.  In previous posts we have described the use of trunnels as the frame came together.

Now that the sheer-strake and bullwarks are in place and the tops of the double-sawn frames have been cut to level, some cuts have exposed the trunnels used to fasten the futtocks together.

trunnel remnants in futtock

trunnel remnants in futtock

The hull frame is nearly done and drilling holes and bolting the sheer-shelf to the frame is one of the last steps.

Dave gives the scale of the timbers of the frames, bulwarks and the substantial horizontal sheer-shelf which provides stability to the hull and will support the aft deck beams. And is a handy shelf for the crew as they work.

Here's a different perspective of the port sheer-shelf.

Meanwhile Chris drills a very long hole through the sheer-shelf and frame on the starboard side.

The crew developed this ingenious jig to guide the drill bit true.

It is important that the hole be straight to accept the silicon-bronze rod and to be centered to the end through the frame and sheer-strake so that the bolt holding the structure together will be secure.  This short video shows how long the bit is and how the jig is adjusted.

Trunnels for fastening the 3 inch planking, note the slit in the right end which accepts a wedge to tighten the trunnel in the hole.

On the left you can see one wedged trunnel and two silicon-bronze screws, on the right two more screws and two wedged trunnels.

Project Manager David Short explained that trunnels will be used to fasten the planks to all the frames as this photo shows. The screws will be used at the butts and the setts.

Silicon-bronze screw for planking.

Tapered drill bit cuts tapered screw holes

As Julius said this summer, “We are getting a superior ship” thanks to the shipwrights at Bristol Marine’s Shipyard in Boothbay Harbor.

  |