Naval History & Heritage Command Detachment Boston ship restorers have been hard at work since the ship entered dry dock in May 2015. Here is an update on current projects.
USS Constitution is covered below the waterline with 3,200 copper sheets. A major part of the current restoration is to remove the copper that was installed in August and September 1995 during the last dry docking. Each sheet is 14 inches x 48 inches and weighs 6 pounds and is held in place with up to 150 copper nails. Behind the copper is “Irish felt,” a type of roofing felt that helps to protect the white oak hull planking. Each piece of felt is held in place with several dozen copper tacks.
Copper removal is difficult and tedious work. Hammers, crowbars, and pliers are all employed in peeling away the overlapping sheets. At the waterline, where the ship’s hull planking is not constantly submerged, the wood softens overtime and is prone to rot. The softer wood makes copper removal easier. Below the waterline, where the wood is constantly wet, the hull planking is better preserved. This stronger wood grips the copper nails, making removal more difficult.
Removing the hull planking is a multi-step process. The white oak planks are held in place with galvanized spikes. To remove the spikes, ship restorers must first drill and chip to expose the head of the spike. Once the head is exposed, it is gripped by a pneumatic pin-puller and extracted from both the hull plank and the frame behind it. The first planks removed from Constitution‘s hull are in the starboard bow.
Joshua Humphreys, principle designer of USS Constitution and the other five frigates in the 1790s, argued for the use of live oak for the warships’ framing. He noted that while it would cost five times more to cut and ship the live oak than white oak, the live oak frames would last five times longer because of the wood’s dense, rot-resistant nature. While about 10 percent of Constitution‘s original framing remains, mostly the bottoms of the frames known as floor timbers, that framing is still in good condition after 220 years. Most of the framing above the waterline was installed in the 1927-1931 restoration, and after 89 years is still structurally sound. Humphreys was correct in his prediction.
The first new plank was installed on Constitution‘s starboard bow on September 21, 2015.
The rotten planks, which were installed between the 1980s and 1990s and are made of laminated white oak, will be removed in the next several weeks. These planks have rotted because they are above the waterline and are exposed to all weather. The vertical oak timbers seen in the photos above and below are “strong backs” and are used to apply pressure to hold the new plank in place before it is pinned.
In preparation for work on Constitution‘s stern, most of the carvings–including her stern eagle, decorative rails, stars, and pilasters–have been removed for refurbishment. Over the next several months, select planks will be replaced on the ship’s stern.
Gun Deck Waterways
The waterways are the timbers that connect the sides of the vessel to the deck and form a channel to carry water off the ship through the scuppers (openings on the deck). The gun deck waterways are being replaced port and starboard from the bow to the bulkhead at the entrance of the Captain’s Cabin. In order to replace the waterways, the two outermost deck planks must also be removed.
The old waterways are cut out in small sections and all the fasteners are extracted with pneumatic pin-pullers.
In the photo below, a large section of the new starboard waterway is rolled into place. The bottom of the waterway is cut so that it overlaps the gun deck beams and ledges, which helps to lock the waterway into place.
This is just the beginning. Restoration work will continue through 2017, at which time Constitution will be re-floated and returned to her dock at Pier 1. Check back often for more updates on the restoration work and remember to visit Constitution Cam for round-the-clock, real-time views of the ship.
– M. M. Desy & K. Monea
USS Constitution Museum