This winter, the Flagship Niagara League tackled their most significant and expensive ship maintenance project ever… a complete re-caulking of the ship’s weather deck, which cost nearly $70,000. To understand the magnitude of a project like re-caulking the deck, one must first know a bit about it. The ship’s decks are planked with Douglas Fir, which is a high quality pine found most abundantly in the Pacific Northwest. While the ship was certainly planked with local lumber originally, Fir is widely accepted today as the best and most commonly used deck material on large wooden vessels. It is light weight and fairly rot-resistant. 
A deck plank on Niagara and on many ships of her size is typically three inches wide by three inches thick by about twenty feet long (see the adjacent diagram). The seams between the planks are about one quarter of an inch wide, and are formed by a bevel that is cut into the outboard edge of each plank. The bevel is cut on only the outboard side of the plank so that the seam is square on one side and beveled on the other.
Before a deck can be re-caulked, the old material in the seam must be removed, or “reefed out”. The process of reefing out the deck seams involves using an iron hook and a bronze mallet to pound the tapered hook into the seam in such a way that it hooks the material, and the worker pries the handle and levers the material out of the seam. The worker must be very careful not to damage the sides of the wooden seam. To do this successfully, he or she must know a few tricks of the trade, and I’ll spare you the details here.
Once the seams are cleaned out and all material is removed, they are ready for re-caulking. Occasionally when reefing the seams, we find wood rot, which must be repaired. If the rot is extensive, sometimes the entire plank and adjacent plank must be replaced. This year we replaced about a dozen short planks in several areas of the deck.
In a ship’s deck, planks are nailed in place such that they touch each other on the bottom and the “V” shaped seam on top must be caulked. Caulking means to fill the seam with a layer of heavy cotton yarn and several layers of hemp oakum (another type of thick yarn), which keeps water out of the seams. Each layer of cotton and oakum must be driven into the seam with caulking irons and caulking mallets. The layers of material are aligned in a swirl pattern using a “threading iron” and a light weight caulking mallet as the material is tucked quickly, but gently into the seam, and with even and consistent distribution along the seam. This constitutes much of that part of the traditional caulker’s skill, which many people refer to as “magical voodoo”.
Then, the “tucked” cotton yarn is driven tightly into the seam with a wide-faced, thin-edged caulking iron and a light weight caulking mallet. Then the first layer of oakum is threaded into the seam overtop of the cotton, in the same swirl-pattern fashion as was done with the cotton. Again, like with the cotton layer, the oakum is then driven into the seam with a medium-sized caulking mallet.
Next, a 2nd layer of oakum is driven in similarly to before, and in some seams, a 3rd layer is sometimes required. After caulking the seams, they will be nearly filled with material, and will then need to be “Beetled Down”. The “Beetle” is a very large wooden mallet that is used with a heavy “horsing iron” to pound all of the cotton and oakum layers tightly and deeply into the seam, leaving the top ½” of the seam vacant. In the top ½” of the seam that is left, hot pine tar pitch is poured to seal the top of the seam to prevent the oakum from getting wet, but also to prevent it from creeping out of the seam if it does gets wet and expand. The oakum and cotton keep the water out…the pitch keeps the oakum and cotton in.
The Niagara’s deck is comprised of about 350 planks arranged in roughly 20 foot lengths. That is equal to about 7,000 linear feet of seams that must be completely reefed out and re-caulked every 20 years, then should be “beetled down” again about every 7 years to keep the water out, the decks free of rot, and in good condition. Over the last few years we have delayed this project, and we could simply wait no longer. This project cost the Flagship Niagara League about $70,000, and saved the ship from what could have been a much, much more expensive proposition just a year or two from now. Rot does not rest and in a wooden ship, it must be kept at bay.
This major deck re-caulking project was led by Bob Arlet, who worked for 18 years, first as our AB Seaman/Carpenter, and then as our Shipwright (highly skilled ship’s carpenter). Bob now works with us on a seasonal basis through the winter months. During the spring, summer, and fall, he works full time servicing yachts in Erie and the surrounding area at own company, Arlet Boatworks, Inc. I highly recommend his services. He has certainly done an exemplary job onboard Niagara.
Bob’s crew on this job included Pat Crosby (our full-time Mate/Carpenter, the three free-lance caulkers from Maine, and the six deck laborers who signed on for a few weeks this winter to conduct the back-breaking and highly skilled labor of reefing and traditionally re-caulking Niagara’s weather deck. They did a great job. All of the caulking is now finished, and the final scraping of the deck and repairs to rotten planks will be finished by the end of February.
Finally, I’d like to thank everyone who worked on this project, and all of our members, donors, Tall Ships Erie patrons, and museum visitors who made financing such a vital maintenance project possible.
Capt. Wesley Heerssen
US Brig Niagara