Page 1


R ebuilding


C.A. T hayer

Please join us as we celebrate years of hard work by volunteers and staff toward the restoration of our beloved C.A. Thayer. At our request, Bay Area school children and our members wrote letters to Congress in support of allocating funds to restore the C.A.Thayer, and we and the Park are deeply grateful for this support. Our Association is proud to have contributed to the success of this project, a landmark in wooden ship preservation. We invite you to visit Hyde Street Pier and see for yourself the beauty of the restoration first-hand. As you will see in this issue of the Sea Letter, the Thayer returns to Hyde Street Pier with a nearly new hull, but will require further work to fully restore her as a premiere example of a Pacific Lumber Schooner. This work will commence immediately and be performed pier-side by the Park Service. While the Park continues to fund many of the major restoration components, the Association is raising funds to refit the Thayer with her sails, rigging and masts — key to her majestic silhouette at Hyde Street Pier. When the restoration is complete, we will welcome back on board classes of students to participate in our nationally acclaimed Age of Sail education program. After that, our ultimate dream is to see the C.A. Thayer sailing on San Francisco Bay, an ambassador of goodwill for the San Francisco Maritime National Historical Park, the National Park Service, and our Association. Generous donations from you, our members, help us achieve these goals and we sincerely thank you for your ongoing support. Sincerely,

Deborah Hornberger President San Francisco Maritime National Park Association Board of Trustees




C O N T E N T S 3

The Last of the West Coast Lumber Schooners by Kate Richardson

4 The History of the C.A. Thayer by M.J. Harris 3

6 Rebuilding the C.A. Thayer by Stephen Canright

9 Deciding to Rebuild and Restore


Frame Timbers 8

19 Caulking the Hull

Front cover: The Thayer is being readied to go back to Hyde Street Pier. 2006-04-24(28) Back cover: The main deck is finished. 2006-06-12(1)


Š 2007 by the San Francisco Maritime National Park Association. All rights reserved. Printed in the United States of America. Printed on recycled paper

San Francisco Maritime National Park Association

Why Save an Old Schooner? There are not many big wooden sailing vessels left in the world. If we look for what remains of the age of wooden sail, we see a handful of warships—the Vasa, the Victory, the Constitution, and the Constellation. These are state ships, preserved to commemorate a national tradition of naval glory. Merchant vessels have never stirred the national soul quite as much as warships. In this country, no clipper ship was saved, nor a packet ship, nor a square-rigged Down-Easter, nor one of the big East Coast schooners. We have one whaling bark, the Charles Morgan at Mystic, Connecticut. A handful of wooden fishing schooners and smaller cargo schooners survive. On the West Coast, we have the schooner Wawona at Seattle, Washington, and our own C.A. Thayer. Outside the United States, there is only one wooden merchant square-rigger, the bark Sigyn in Finland, and again a scattering of smaller schooners. Certainly there are hulks and wrecks tucked into backwaters, but intact wooden vessels? Only these very precious few. It is hardly surprising that so few big wooden vessels have survived. Wood is ultimately a biodegradable material. A wooden hull begins to rot the moment it is put into the water. It will be eaten by worms or beetles, or will self-destruct from the very strain of floating. Good care and good luck might prolong its life, but a wooden ship was ultimately disposable. The West Coast lumber schooners were considered to have a useful life of about twenty-five years. They were never intended to last forever. Given this underlying reality, were we foolish to make the effort to keep the C.A. Thayer alive? Was it worth the money, the labor, the timber? What is the price of our history? What is the price of inspiration for our children? The C.A. Thayer is a tangible link with both our maritime history and the commercial growth of the old West. The Thayer shows us the life of the coasting seaman. She speaks of man-killing labor, and of the bond between vessel and crew as they jointly dare the hard leeward coast through any condition of wind and sea. The Thayer shows us how the daily work of these men and this vessel—the prosaic task of moving cargoes of timber —settled and built the frontier coast, from the rough mill towns of Washington to the gingerbread palaces of San Francisco. In the Thayer, we experience a wooden island from another age. Isolated from the land, she is a contained environment where a generation of strong men and resilient women both lived and worked. Standing in the hold, or in the after cabin or in the cramped galley, we can feel their presence. Thousand of schoolchildren, living and working aboard only overnight have felt this connection. They are flung backward to a time when only hard work, commitment to tasks, and strength of character were considered. The Thayer projects these simple realities to all who encounter her. For those of us privileged to have been involved with the restoration of the Thayer, she has revealed hidden subtleties previously known only to her original builders — the spring-loading of her keel against the stress of floating, the way her sheer clamps forward tie the bow together, or the intricate fitting of her waterway timbers. These secrets reveal something of the thought processes of her builders, and leave us with a profound respect for the mysteries of the shipbuilder’s art. Again, we are flung back in time, now to sit at the feet of masters. The Thayer has survived wars and natural disaster, voyages in Arctic waters, hard slogs along the coast, and rough service for the U.S. Army. She has survived intact, and is still able to tell her stories. We must complete her rebuild and pass her along, whole, to those who will rise behind us. It is they who will ultimately care for her and keep our cultural, historical, and spiritual connection with our past alive.

Stephen Canright, Curator of Maritime History San Francisco Maritime National Historical Park

President Deborah Hornberger First Vice Presidents Sanford Livingston, Jr. Susan C. Rogers Gregory J. Ryken Thomas Thompson secretary Michael Meyers Treasurer Robert S. MacIntosh Trustees James Andrasick Neil D. Chaitin Michael Dowling Robert H. Enslow Mary Foley, RN Anne Halsted Steve Kapp Tim Kochis Tom LaTour Michael McDonnell Harry Nystrom Dr. David Sanchez, Jr. Anthony Sandberg Robert F. Sappio Lilly Stamets Edward Suharski John R. Tregenza Senior Trustees Donald D. Doyle George Fleharty Mark Scott Hamilton, Esq. Joseph C. Houghteling David E. Nelson Executive Director Eamon O’Byrne CHIEF FINANCIAL OFFICER Stephen P. Langmaid Counsel

Eric R. Swett, Esq. •

S ea L etter


S an F rancisco M aritime N ational H istorical P ark PHOTOGRAPHY & DIGITAL IMAGE PRODUCTION Tim Campbell Steven Danford

• Comments, suggestions, or story ideas, contact: San Francisco Maritime National Park Association P.O. Box 470310, San Francisco, CA 94147-0310 Phone: (415) 561-6662 • Fax: (415) 561-6660 E-Mail: • Visit the website to order copies of this issue.

The San Francisco Maritime National Park Association is a nonprofit organization dedicated to maritime preservation and education. The Association operates the historic World War II submarine USS Pampanito and supports the San Francisco Maritime National Historical Park. Many illustrations in Sea Letter are taken from the collections of San Francisco Maritime National Historical Park. Reference use of these collections is encouraged, and is available through the Park’s J. Porter Shaw Library and other sources. The opinions expressed in Sea Letter are those of the authors and do not necessarily reflect the views of the San Francisco Maritime National Park Association.

Gail Hynes Shea, Managing Editor Sea Letter magazine 2


The Last of the West Coast Lumber Schooners


by Kate Richardson

n this issue dedicated to the C. A. Thayer, one of San Francisco Maritime National Historical Park’s flagship historic vessels, you will read about the vessel’s history, rebuild, and future. I would like to focus, though, on the people of the Thayer. We know quite a bit about the individuals who built and owned the C.A. Thayer, but less about the people who worked her. And less still about the families whose lives turned on the commerce the Thayer generated. I always wonder — what far off places might a young child dreamed of, standing on the shore and waving as this magnificent vessel sailed by? What did the workers who loaded and unloaded her cargo hope and plan for? Who were their families, and how did they live? What was it like to be Carolyn Peterson Maurer, who spent the first five years of her life aboard the Thayer? When she was just 3 months old, in 1907, she crossed the Pacific under sail to Honolulu, Hawaii! Fortunately, we do have some of Carolyn’s words, “When the ship rocked and rolled, I just slid from one end of the cabin to the other. I loved it. When it was calm and I wanted to go somewhere, I just pushed along on my bottom.” And what do our students remember about their participation in the park’s overnight program? Colin Degen, who learned how to cook in a ship’s galley twenty years ago, still recalls the poem he wrote about that experience back in 1985: our flag waves proudly over the sea, darkness at night is as dark as space. gulls crying their loud and squawking noise. stove sizzling like the sun on a summer day. burning wood reminded me of home, by the fireplace. food cooking smelled like my mother’s cooking. pancakes tasted like my mother had made them. stew tasted like cooked meat work wasn’t as hard as I thought. felt good about myself on the voyage

As you read this issue, I urge you to remember all of the Thayer’s people: past, present, and future. Honor her builders, her crew, all the families she touched, the ones who fought to save and restore her — and, of course, those who will continue to protect the Thayer long after we, ourselves, have passed into history.

Kate Richardson Superintendent San Francisco Maritime National Historical Park



The History of the

C.A. Thayer by M.J. Harris

On July 9th, 1895, a crowd gathered at Hans D. Bendixen’s shipyard on the shores of Northern California’s Humboldt Bay to watch the launch of the C.A. Thayer. “Miss Mabel Scott, of this city, christened the vessel, and as the crowd were waiting with baited breath the vessel started like a thing of life, and going faster and faster glided out on the water, its home for ever and ever. As the bow struck the water the bottle of champagne was broken and success and long life were wished the new-born vessel.” (Daily Humboldt Standard, July 9, 1895)


seventeen years and made eightyhe C.A. Thayer was four voyages as a lumber schooner launched 112 years ago for the E.K. Wood company, carryin Humboldt Bay by her ing lumber along the Pacific Coast, builder, Hans Bendixen. and to Mexico, Honolulu, and Fiji. She was a three-masted lumber She was instrumental in supplyschooner. Her registered measureing lumber to San Francisco from ments were: 156 feet in lengh, 11.8 Gray’s Harbor, Washington, to refeet in depth, a beam of 36 feet, and build the city after the earthquake a gross tonnage of 452. She was and fires of 1906. built of the same Douglas fir that In January 1912, at what turned she would carry for much of her out to be the end of her life as working life. She was named after a working lumber schooner, the Clarence A. Thayer, a partner and The C.A. Thayer sets out for Bristol Bay, Alaska in April of 1912. The Thayer carried supplies for the Thayer was caught in a storm off secretary in the E.K. Wood Co., the summer salmon season and a deckload of lumber for the coast of Oregon, about 30 miles lumber company with a small, but construction at the Nelson family saltery. This is the from the mouth of the Columbia managing, interest in the vessel. best photo that survives of the Thayer under sail with River. It took the efforts of the The C.A. Thayer was large for a her original gaff mizzen rig. J7.5134n whole crew pumping continuously three-masted schooner. Her “baldfor four days to save her. She eventually made it to San Franheaded” (no topmasts) schooner rig required only a small crew cisco under tow, with 24 inches of water in her hold. of four seamen, two mates, a cook, and a captain to sail her. When fully loaded, she could carry up to 575,000 board feet of lumber, and was a typical Pacific Coast lumber schooner. She was able to carry a large, bulky cargo in one direction with the smallest possible crew, and then sail back again with no ballast. The Thayer was beamy and had a shallow draft, which helped her and her sister schooners battle the difficult sailing conditions of the Pacific Coast — rocky coastline and “dog-hole” harbors (inlets a dog couldn’t turn around in). Today she is one of only two Pacific Coast lumber schooners left anywhere in the world — the other is the Wawona, currently moored in Seattle, Washington. Before she became a museum vessel, Thayer served through four separate careers: lumber, salmon, codfishing, and as a pirate ship tourist attraction. After her launch in July of 1895, the C.A. Thayer served

M.J. Harris is the Age of Sail Program Manager at San Francisco Maritime National Park Association.



“With the notable increase in the average size of lumber carriers, and the advent of the steam schooner, the Thayer was obsolete in the lumber trade after only seventeen years. She survived only by moving to a lower tier of economic usefulness in the fishing trades.” A few weeks later, the C.A. Thayer was sold to Peter Nelson and began her second career in the Alaska salmon trade. For thirteen seasons Nelson took the Thayer to Alaska’s Bristol Bay to supply and carry goods to and from his salmon saltery there. Interviews with Nelson’s crew describe a life that sometimes required the fisherman to go for days without sleep—until the salmon season was over and the Thayer had taken on her limit. When fully loaded, the Thayer was able to carry about 6,000 barrels of salted salmon. Naturally, this impeded her sailing ability, but got the job done. As the 20th century progressed, sailing vessels were increasingly replaced by more efficient steam schooners, and the Thayer was sold in 1924 to Captain J.E. Shields of the Pacific Coast Codfish Company, who used her to transport about 300,000 pounds of salted codfish annually from the Bering Sea. Her first skipper as a codfishing vessel was John Grotle, who captained her until 1931 when a decline in the price of cod, as well as the economic collapse that followed the Depression, led to her mooring in Lake Union, Washington, for the next eleven years. When the U.S. Army took over the Thayer in 1942, she was decaying and in desperate need of repair. The Army allocated the funds to repair her hull, but ultimately cut down her graceful masts and used her as a barge in British Columbia and southeast Alaska—a humiliating fate for such a beautiful vessel. In 1945, after World War II ended, the Thayer was briefly returned to work as a codfishing schooner when she was re-purchased by Captain Shields. Shields removed the masts from his schooner Sophie Christenson, and made the Thayer seaworthy again. The Thayer’s new masts were ugly, but functional, and served her in the codfishing industry for another five years.

The C.A. Thayer was purchased in 1950 by Captain Charles McNeal, who used her at his waterfront resort on the Hood Canal as a pirate ship tourist attraction. The disturbing pictures of her during this stage of her life reflect her desperate need for repair, and the often sorry fates that befell sailing vessels from the late 19th century as they deteriorated from disrepair and neglect in the age of steam. Karl Kortum, founding director of the San Francisco Maritime Museum, recognized the importance of the once-great schooner, and arranged for her purchase from McNeal for $25,000 in 1957, and she became the property of the California State Parks. The C.A. Thayer will again take her place at Hyde Street Pier alongside other vessels that helped build San Francisco and the maritime history of the Pacific Coast. She has found her final harbor in the protective waters of the San Francisco Maritime National Historical Park, where she is visited by thousands each year, and even serves as a floating classroom for elementary school students learning about San Francisco’s rich maritime heritage. Her preservation is a gift to future generations and to maritime history. Above: Peter Nelson was a good employer by all accounts. “Whitehead Pete,” as he was nicknamed, was a colorful character. He did most of his business in local saloons, and tried to incorporate music and dancing on the deck after a hard day’s work when it was possible. He took his family with him on the Thayer on the voyages to Nelson’s salmon saltery in Alaska. Nelson’s daughter, Hilda (seen here at the wheel of the Thayer), was a high-spirited girl who would start the whole crew dancing. J9.8,465n

Inboard profile of the Thayer Drawing by Don Birkholz, Sr. Tricoastal Marine, 1989



e h t g n i d l i u Reb

C .A.T er ay .Th C.A ha ye r by by Stephen Stephen Canright Canright

On December 2, 2003, with due ceremony, the C.A. Thayer, one of her masts missing, was towed from Hyde Street Pier to Bay Ship & Yacht on the Alameda side of the Oakland Estuary. The tug is the Alert out of Sausalito. 2003-12-02-923


he scale of the work on the West Coast lumber schooner C.A. Thayer is without precedent in the history of maritime preservation. The Thayer, 168 feet long on deck and registered at 452 gross tons, will emerge with more than 85 percent of her hull fabric replaced. This is easily the largest wooden merchant shipbuild-

ing project completed in the United States since the 1920s. The end-point is not a new vessel duplicating the original, but rather the original renewed, with the strength to float for another century. As early as the late 1970s, when the National Park Service took over the Thayer, her hull was fatally weakened with dry rot in the upper frame timbers.

Douglas fir is a lovely shipbuilding timber, but it is a softwood and is famously susceptible to rot. The traditional structure of a wooden ship, with the frames encased between the outer hull planking and the inner ceiling planking, is an ideal breeding ground for rot. When rainwater finally seeps into the structure, the frames stay wet and rot takes hold.

Stephen Canright is the Curator of History at San Francisco Maritime National Historical Park, as well as Guest Editor of this issue. 6


The work of stripping down the Thayer got underway while she was still afloat, her two remaining masts (there were originally three) and bowsprit were removed. The anchor windlass and capstan came off, as did the anchors and chains. The stone and zinc ballast came out of the hold. Most of the forward deckhouse was dismantled and discarded, saving only the forward-most 6 feet, a remnant of the original lumber period deckhouse. 2003-12-12(1)

The softening of the Thayer’s frame timbers left her ever more susceptible to hogging, another killer of traditional wooden vessels. Hogging occurs when the ends of the hull droop down in relation to its midpoint, bending the keel into an arc. The ends, as they narrow at the bow and stern, have less buoyancy than the wider midbody, and are effectively heavier. Over the years, the weight differential takes its toll and the bow and stern sag. Any large wooden hull will hog to some extent, but West Coast schooners like the Thayer are particularly prone to hog. Designed with relatively shallow hulls to cope with the offshore sandbars NUMBER 68

of West Coast ports, the schooners had less effective longitudinal girder strength than the deeper, narrower hulls of the East Coast square-riggers. The Thayer was profoundly hogged, and something had to be done.


ne of our objectives in the rebuild was to return the vessel to her asbuilt configuration, reversing changes made to her deck, cargo hatches, and deckhouse over the years. Our assumption was that she was best presented as a representative of the West Coast lumber fleet, seen as her designer and builder had intended. While the Thayer was being stripped and lightened, preparations for hauling her out began. A steel cradle was welded together on the floor of the Bay Ship

dry dock. This massive pallet of steel Ibeams would hold the hull, braced with steel struts, throughout the rebuilding process. With the cradle finished and sitting in the dry dock, the dock was flooded and the hull was towed in. Divers helped to spot the keel directly on the centerline blocking, and locate it precisely fore and aft. The blocks were set to accommodate 12 inches of hog, 4 inches fewer than the 16 inches actually measured in her keel. This was the first real bit of restoration. The first 4 inches of bend were straightened out of the hull as she settled onto the blocks. With the dock pumped dry, the vessel rested on the cradle. Bilge blocks from the dock floor held her steady until steel support struts were welded 7

Above: In the glare of portable light banks, the Thayer and her cradle were driven onto the barge. As the weight of the cradle came onto the bow of the barge, water ballast was pumped into the barge’s stern compartment to compensate and keep the bow from sinking. The cradle, although massively built of heavy I-beams, was still subject to flexing along its 160-foot length, and constant attention was required for the hydraulic rams to hold the plane of the cradle straight and level. Ever so slowly, over about eight hours, the transfer proceeded, pumping ballast water in the barge and in the dry dock and adjusting the height of the rams as the cradle moved ahead. At the end of a very long and tense day, the Thayer and her cradle floated securely on the barge. 2004-01-10(12)

Left: The hydraulic control station at the rear controls the self-propelled dollies and corrects for any flex in the cradle. As dawn broke, the Thayer and her cradle were driven across the runway and into the huge seaplane hangar that would be the site of her rebirth. 2004-01-13(8) 8


to the cradle. The next challenge was to pick up and move the cradle and hull as a single unit. Sixteen house-moving dollies were hoisted into the dock and slipped under the cradle. Each of the dollies was fitted with hydraulic jacks, and four of them also had propulsion

a massive scale, and never depended on any newly derived design. With the scan finished, one Bay Ship crew began erecting a wooden scaffolding system around the hull, while another gang started on the removal of the main deck planking. With the deck planking

Deciding to Rebuild and Restore

The Thayer has just been rolled into the old seaplane hangar. The house-moving dollies are still in place. The cradle will be landed onto blocks to provide a straight and level building platform. The keel still shows 12 inches of hog at this point. For the first time since her launching in 1895, the Thayer stands on dry land. 2004-01-14(1)

and steering systems, so that the cradle and hull could be both lifted and driven slowly ahead. A square-ended barge was positioned at one end of the dry dock, and the cradle was slowly driven onto the barge. Next morning at high water, about 3:00 am, the barge was towed around the tip of Alameda to the edge of the old main runway at the former Alameda Naval Air Station, where it was brought ashore. With the steel cradle blocked solidly on the hangar floor, the first step was to make a laser scan of the hull. This was done for documentation purposes, rather than as a guide for the reconstruction. As the project went ahead, all of the new timbers would be patterned directly from the hull, not from any drawings. It would certainly have been quicker to rebuild her from a crisp new design drawing, but this way of working — replacing deteriorated material piece by piece — ensured that the Thayer was in fact rebuilt rather than replicated. We were doing ship repair on NUMBER 68

A worker pulls up deck planking using an overhead gantry crane. The tired planking did not put up much resistance, splintering and breaking at the centers of the deck beams on the lines of the spike fastenings. At the rear, the afterhouse can be seen. 2004-01-23(6)

Between the rot, the hog, the deterioration of her steel fastenings, and some scary structural problems in her stern, the Thayer could clearly not have continued to float indefinitely. If she were to be preserved, we had two broad options: rebuild or reinforce her sufficiently to remain afloat, or try to preserve her ashore in some protected condition. The idea of preserving the schooner ashore had a very real appeal from a purist point of view. It would theoretically be possible, given the best engineering and conservation technology, to preserve the original fabric of the vessel indefinitely. The hull could be cradled, in a purposebuilt and climate-controlled building, and treated as a museum object. There would certainly be a loss of the vessel’s original context, but the fabric could be preserved. The practical difficulties and astronomical cost of such an approach, however, effectively precluded its serious consideration. If the Thayer were to be maintained afloat, we could either rebuild her in original materials, or attempt to reinforce the structure with some modern materials, possibly enabling us to retain more of her original fabric. Various schemes were discussed — build in steel beams to straighten her keel, insert carbon fiber rods to strengthen her framing, even using air bags to counteract the hogging stress. Finally, however, we concluded that any such methods would compromise the historical integrity of the vessel without fully addressing the progress of her deterioration. If the Thayer were to be saved, it could only be done by restoring the original integrity of her designed structure.


off, we got our first look at the framing timbers of the vessel. All of the deck beams showed some rot, and all would ultimately be replaced.


ebuilding a wooden ship requires a  ruthless approach to cutting away material to get at the underlying frame timbers. The bulwarks were cut off in 8-foot lengths. We then started on the topside hull planking — the hull planking above the waterline. We knew that this planking was largely rotten and consisted mostly of replacement planks. We could identify the few remaining original planks because they were fastened with trunnels (long dowels made of locust wood), which were originally used to fasten all hull planking. We carefully noted how these planks were fastened. We sacrificed the topside hull planking with a relatively easy mind. We were much less eager to scrap the wider bottom hull planking, much of

which was in 80 and 90-foot lengths. Fortunately, we were to find that both the planks and the frame timbers in the bottom were in generally good condition, having always been soaked in salt water. Dry rot does not grow in salt water, and this was the very thing that made the Thayer job possible — we were able to build up from a foundation of sound original material in the bottom frame, keel, and planking. Had these timbers been rotten, we would

have had to write off the whole vessel and start from scratch. With the topside and main deck planking stripped off, the hull was as limber as it was going to get, and we turned to the job of settling out the remaining 12 inches of hog in the keel. The idea was that the keel could be straightened by just the weight of the hull, backing down on jacks and wedges in a smooth and controlled fashion. The keel, in fact, came down easily and

The midship section of the C.A. Thayer. A lot of the vernacular of shipbuilding is graphically illustrated here.

garboard strake rabbet


wormshoe With the bottom of the keel dead flat, the line of the rabbet still showed some 4 inches of arc. The rabbet is the junction of the keel and the garboard (or bottom) strake. 2004-04-01(2) 10


quickly. After only six hours, the keel was dropped to a level line of blocks. We were surprised, however, to see that, even with the bottom of the keel leveled, almost 4 inches of arc remained in the line of the rabbet — the joint between the keel and the lowest hull plank. We determined that there were two separate things going on. First, the forward 40 feet of the 4-inch wormshoe (a sacrificial plank on the end of the keel that takes abrasion from grounding or attack by worms), was missing, allowing the forward end of the keel to sag. The forward wormshoe had probably been missing since 1903, when she grounded at Grays Harbor, Washington. The fix was easy enough. The forward part of the keel was jacked up and a new wormshoe section installed (see illustration of midship section, left). Even with the bow raised this much, however, there was still about 3 inches of arc in the line of the rabbet. We had to lower the midship blocking by 3 inches to straighten out the rabbet. The only explanation was that the vessel had been built with a bit of spring-loading against the hogging that was certain to arise when the hull was first floated. The first bit of hogging deformation would have actually bent the keel back toward a straight line. Then, as at several other points, we would stand back and marvel at the ingenuity of the original designers and builders. With the hull blocked to its approximate shape, the work of replacing rotten frame timbers could begin. The first step was to install ribbands along the hull. Ribbands are long wooden battens, about 2½ inches by 1 inch, by at least 40 feet long. These were screwed to the outer surface of the frames with drywall screws, their upper edges landing, as nearly as possible, on the seams of the old topside hull planking. The inner surface of the ribbands stood in for the hull planking. The shape of each piece of frame timber to be replaced could be patterned from the space between the ribbands outside and the ceiling planking inside. The renewal of the frame timbering began with the designation of every fifth frame as a “station” frame. The process of reframing was worked out in the course of renewing the station frames, beginning with Frame #25 on the starboard side. NUMBER 68

Ribbands are being installed to mark the runs of the original hull planking. The chalk numbers indicate frame numbers. 2004-05-17(5)

Frame structure and futtock numbering diagram. Drawing by Eric Balderston, Bay Ship & Yacht. 11

Station Frame #25 (just behind lead shipwright Phil Irwin) was the first sound, new material put into the 112-year-old hull of the Thayer. Frame #25 was in the relatively straight-sided mid-body of the hull, where there was little bevel in the inner or the outer faces of the frame timbers. It was the best area to practice the patterning, shaping, and installation of the new futtocks. 2004-04-26(5) Inset: Two frames have been renewed on either side of a frame waiting to be replaced. Ribbands mark the course of the old hull planking. 2004-06-17(4) 12


lumber ports

The stern view shows the lumber ports. HAER CA-61, sheet 14

Through most of the length of the hull, the new upper futtocks could be joined to sound existing lower timbers. We had to remove most of the inner ceiling planking in order to get at these lower frame timbers. This “thin ceiling,” below the turn of the bilge, was 4 inches thick. For the most part, it was not in bad condition, but had to be sacrificed. We preferred to cut out the thin ceiling rather than the outer bottom planking. The thick upper ceiling planking, running through the turn of the

bilge and up to just under the main deck, was temporarily left in place during the re-framing process to serve as a pattern for the hull shape. It was entirely rotten, however, and was eventually replaced. It was only in the ends of the hull that the lower sections of the framing timbers were rotten and had to be replaced. Over the years, fresh water had sometimes pooled in these sections and rot had taken hold. We ended up removing and replacing the bottom timbers of the last four full frames in both the bow and the stern. To do this, we had to remove portions of the lowest strake of bottom planking — the garboard strake — and sections of lower sister keelson timbers fore and aft. Dealing with the keelsons proved a tricky proposition. Six keelson timbers, each about 18 inches square, run down the centerline of the hold, strongly fastened with steel drift rods to the upper surfaces of the frame timbers. This stack of heavy timbers is a vital strength mem-

After the station frames were in place, the long and repetitive process of wrecking out and replacing the intervening frames got underway. It would be the work of many months. The new frame sections butt into the original floors and first futtock behind the retained original bottom planking. 2004-06-30(8)

Frame Timbers The Thayer’s frame timbers, like those of almost all traditionally built wooden ships, are double-sawn. Each frame is built up of pairs of individual timbers called futtocks. Each futtock is sawn out of 10-inch thick, straight-grained material. Each frame is two layers of 10-inch futtocks, or 20 inches thick fore and aft. The futtocks are arranged so that the joints, or butts, in one layer lie midway in the solid span of its framemate. The butts are simple right angle joints. The whole structure is firmly tied together with wooden dowels, or trunnels, driven tight through the full 20-inch thickness of the finished frame. In original construction, a full frame was fastened together on a flat floor and then lifted in place as a unit. In repair work, like the Thayer job, the futtocks of the standing frames must be replaced individually, and the process is very laborious indeed.


The massive stem post is the forward-most timber in the hull, and forms the forward point of the bow. The stem was a huge timber, 18 by 40 inches by 25 feet long. We had trouble convincing the Canadian government that this was a finished piece, and not a log to be re-sawn. 2005-06-13(15)


ber in the hull, and helps the keel resist bending. The timbers are in lengths of at least eighty feet, with long scarf joints between the segments. The degree of rot in the keelsons was not immediately evident. We could see that there were pockets of softness around the steel drifts due to rusting iron that was poisoning the surrounding wood. This degree of weakness we were prepared to live with, but these soft spots might well have allowed freshwater intrusion deeper into the timbers, making for deep, hidden rot pockets. We decided, in the end, to remove the whole of the upper sister keelsons on either side. The lower sister keelsons looked good, and we would have left them undisturbed, except for the need to get at the lower frame timbers in the very ends. The centerline timbers of the bow and stern showed serious pockets of rot, and had to be replaced. The stem post, the heavy vertical timber in the very bow, had been partially replaced in 1961, but the top of the original lower section was now rotten. This timber, together with the apron timber that backs it up, was replaced as a single piece as per the original design. The structure of the stern of the Thayer was a weak point in the original design. The location of the stern timber ports, which are immediately alongside the stern post, left no room for longitudinal horn timbers, which normally stiffen up the overhang of the stern. As designed, the stern got much of its strength from the heavily reinforced bulwark structure and the framing of the raised poop deck. Unfortunately, this bulwark structure had been weakened by hasty repair work done in the 1950s and by rot in the intervening years. By the time of the rebuild, the stern overhang had sagged off by about 6 inches. In the end, we largely restored the designed strength of the stern overhang and the transom. A new upper section of stern post, new rudder trunk, strong quarter knees, and full ceiling planking were installed inside the after section of the bulwarks. The shape of the upper portion of the transom, which had been shortened when the U.S. Army had the vessel in the 1940s, was returned to its original configuration.


Above: A lumberjack harvests a grown knee that will become a hanging knee in the Thayer. 2003-07-10-knees(8); Inset: View from above. 2003-07-10-knees(7)

Left: Inside the hull, looking aft, the new frame timbers are in place and butted up to the original floor timbers and futtocks. 2004-09-14(5)



While the work of framing was still ongoing, the main deck beams and framing were pulled out. Before the beams came out, temporary cross-spalls were fastened across the thick ceiling planking to prevent the hull from spreading. The main deck beams under the afterhouse were generally in good shape, and the basic structure of the afterhouse retained a fair degree of integrity. We were certainly not eager to dismantle it, but we needed to get at the after portion of the interior of the hull. Bay Ship came up with a very clever approach to the problem: the whole afterhouse, including the deck beams, was lifted on steel I-beams and supported above the hull on steel pillars while the work below was accomplished. As the main deck beams were removed, we were able to assess the condition of the hanging knees. These knees, joining the deck beams to the hull sides, are vital strength members in a traditional wooden hull. They are particularly interesting because they are the only timbers in the hull that are grown shapes, rather than sawn to shape out of straight-grained material. Hanging knees represent a tremendous amount of labor, since knees are cut out of the upper roots of fir trees, preferably the uphill root of trees growing on a steep hillside. These knees are dense-grained material that is much more resistant to rot than normal fir. We were able reuse all but about four of the Thayer’s fifty original hanging knees. By late 2004, one year into the project, the bulk of the new framing was in place and much of the original strength of the hull was re-established. We were now able to remove the diagonal pointer timbers, which helped to strengthen the bow and stern, and to finally remove the thick ceiling planks fore and aft. The 8-inch thick ceiling planking forms an immensely strong structure within the hull. This additional longitudinal stiffness is the only reason that the shallow West Coast lumber schooner hulls worked as well as they did. In order to get every bit of stiffness out of the thick ceiling structure, the heavy planks were scarf-jointed between the planks within each strake and edge-fastened through each plank into the plank below. The result was a single, complexly shaped girder within the hull, able to provide critical resistance to bending stress in exactly the area that rigidity was most needed. 16

Left: The bottom strakes of the thick ceiling planking are being reinstalled. These heavy planks, 8 inches thick, were scarf-jointed for maximum strength, following the original design. The scarfs were shaped prior to installation of the plank. Here we see half of a scarf joint in the upper plank. 2005-01-10(10) Below: The clamp timber was shaped prior to installation. The curve of this timber is sawn into the stock rather than bent. Note the line of the wood grain. 2005-04-21(1)


We were able to replace the thick ceiling with essentially the same material, with 80-foot lengths of magnificent 8-inch fir through the middle of the hull. As in the original design, the bow and stern sections of the ceiling were laid in two layers of 4-inch plank, which is better able to meet the extremes of bend and twist in these areas than are 8-inch planks. The ceiling planks were fastened to the frames with heavy steel drifts, and edge-fastened between the strakes. Once the ceiling was in, our attention turned to the sheer clamp timbers. These are the members that run fore and aft along the top of the ceiling planking, and provide the shelves for the ends of Left: Looking down from the top of the scaffolding, four shipwrights bevel the edge of an 8-inch thick ceiling plank. 2006-02-10(3)

the deck beams to land on. The clamp timbers are essential longitudinal strength members and define the sheer line of the hull. The middle sections of the original clamps were single timbers 114 feet long, 12 inches thick, by 14 inches high. For the replacement clamps, we were limited by the availability of materials to maximum timber lengths of 42 feet, and so had to introduce extra scarf joints into the structure on both port and starboard. Otherwise, we were able to follow the original construction. With the thick ceiling and the sheer clamps in place, the planking of the hull could begin. The Thayer is entirely planked in 4-inch-thick fir, with the single exception of the garboard strakes, which are 6 inches thick. In planning the hull planking, we were forced to make adjustments in the original planking runs to suit the widths

Hull planking goes on the starboard side aft. The ribbands, adjusted to the new plan for the planking runs, are temporarily screwed to the frame. 2005-08-02(15) NUMBER 68


stem post

stem knee

garboard Keel strake


The bow planked up. 2006-09-13(16)

of the planking material available to us. The process of laying out the planking runs is called lining off a hull. The runs of the planking were marked on the hull framing by re-positioning the ribbands to reflect the new lining pattern. As a part of the fairing process, a flat spot, or facet, was planed into the frame so that the flat back face of the plank would bear solidly against the frame. A full-sized pattern was made up in light plywood for each plank section, and the plank, with its proper taper and edge bevel was cut out on the ship saw. Many of the planks were more than 80 feet long. The plank sections at the ends of the vessel were steamed to make them pliable enough to take the extreme curve and twist. While the hull planks were going on, part of the gang turned to installation of the main deck framing. All of the deck beams ended up being replaced. After 18

A shipwright shapes the stern rabbet. The rabbet is the little shelf that receives the ends of the hull planking. Note the extreme curve and bevel in the framing in the after section. 2005-08-30(2) SEA LETTER

The planking was initially re-attached using steel spikes. Only after most of the planking was in place were the trunnels (1¼-inch locust dowels) driven. The trunnel holes were drilled from the outside and through the 20-inch thickness of the finished hull structure, including the outer planking, the frames, and the thick inner ceiling planking. The ends of the trunnels were cut off flush and wedged across the grain to hold them firmly in place. 2005-08-30(6)

Caulking the Hull The Thayer’s hull planking was caulked in the traditional fashion. Before they were installed, the plank seam edges were slightly beveled for most of their depth. When the planks were wedged tightly in place, there This shipwright is caulking the hull planking around the turn was a seam of about one quarter of an inch between of the bilge. John Hartford each strake. A strand of cotton was forced into the was one of two master seam, followed by several strands of oakum, a fiber craftsmen brought down from material like unraveled rope. The process of caulking Puget Sound,Washington, to involves long hours teach the rest of the gang of preparation of the how the work should be done. oakum. Crew members 2005-12-13(1) always get to talking and telling stories, and this job led to the expression “spinning a yarn.” Caulkers usually work alone, on their own assigned berth, or set of seams. They pair up only for the final “horsing down,” or last tightening of the seams. Planking seams below the One man works a long-handled horsing iron, rocking it waterline were filled with along the seam, while the other man strikes the iron with Portland Cement after being caulked. Any excess a heavy wooden mallet called a beetle. Once a seam is is scraped off prior to final horsed, the hard surface of the oakum is about a quarter painting. 2006-05-19(2) inch below the face of the planking. Finally, the last bit of the seam is filled, or paid, with a tar-like seam compound in the topside hull planking, and with Portland Cement below the waterline.


considerable discussion about the camber of the main deck, we decided that the centerline should be 3½ inches higher than the deck edge. While the Thayer showed a lot of variation in camber over her length, we decided to go with the measurement taken at the beam at the forward edge of the afterhouse. We reasoned that the afterhouse front timbers, stacked above this beam, would have prevented any significant changes from the original designed configuration. Another question on the beam layout was: to what degree were the beams designed to be lifted along the centerline by the stanchions? We finally decided to allow about three-quarters of an inch of arc to be bent into the bottoms of the deck beams — just enough to tension the structure without putting too much strain on the fastenings holding the deck beam ends down to the sheer clamps. The rest of the arc required to form the camber was sawn into the top surface of the beams. Most of the beams were 14 inches in sided, or fore-and-aft, dimension, by about 12 inches in depth amidships. Heavier beams, 16 inches wide, were used at the ends of the two cargo hatches. The deck framing work included laying in the carlins, which are the foreand-aft timbers framing either side of the cargo hatches. The hatches were returned to their original configuration, with both main and fore hatches spanning four beams. Three half-beams connected the sides of each of the carlins with the side of the hull. The half-beams were stiffened up with four lodging knees on each side of each hatch, all fastened with heavy drift bolts. The afterhouse, which had been raised up on temporary steel pillars, was now dropped back down, with the ends of the original deck beams resting on the new sheer clamp. New ends were scarfed on the ends of two of the starboard beams to eliminate localized rot. With the deck beams in place, attention turned to the deck edge structure. The first step was the installation of blocking between the ends of the outboard ends of the deck beams as they lay on the sheer clamps. The blocks fit tightly between the beams, and were fastened down into the shear clamps with headed drifts, holding the beams against any fore-and-aft movement. 19

The next major job was the installation of the waterway timbers. These heavy planks, finishing 7 inches in thickness by 11 inches in width, run along the perimeter of the deck, just inside the bulwark stanchions, from the stem post to the transom. The individual lengths of waterway timbers are joined together by long scarf joints. The waterways are vital in establishing the strong upper rim of the hull girder. In the original hull, the waterways were laid in lengths of 80 feet or better, but in replacing them, we were limited to 42-foot lengths. This had to be very high quality material to resist its exposed position on the exposed deck. The waterway timbers could not be bent, but rather were sawn to shape out of wider stock. In the bow of the vessel, where the curves are most extreme, the 11-inch finished pieces were cut out of 7-inch stock, 24 inches wide. For maximum strength, the waterway timbers were notched over the deck beams and into the bulwark stanchions that rise above main deck level. This made it a very tricky piece to fit.

With the hull planked up, the original bottom planks can be clearly seen. 2006-01-18(17)

With the waterways in place, the laying of the main deck planking got underway. The deck planking was 4 x 4-inch material, most of it in lengths of 40 feet. This was, again, very fine material — vertical, tight-grained fir with virtually no knots. A standard caulking bevel was planed into one edge as the

planks were initially milled out. The first of the planking was laid down along the centerline of the deck, and was then worked toward either side. As the main deck planking began to go down, the reconditioned hanging knees were installed under the deck beams. The knees were fastened per

The deck beams are laid in place prior to final installation. The beam ends rest on top of the new shear clamps on either side. 2005-09-13(3) 20


Above: The timber on the outside left is the carlin that frames one side of the hatch opening. Half beams connect the carlin with the side of the hull and are held in place by lodging knees. 2005-12-13(4) Right: Blocking between the outboard ends of the poop deck beams; the blocking arrangement on the main deck was similar. 2006-10-03(6)

A scarf joint in the waterway timbers. 2005-11-08(9) NUMBER 68

the original design, with about a dozen heavy drifts driven from the inside. The caulking of the main deck planking began even before the deck was fully laid. The process was similar to the caulking of the hull planking, except that the seams were paid with hot marine glue, a tar-like pine resin material. The new main deck planking had to link up with the original planking inside the afterhouse. The old sill timber, which formed the forward face of the base of the afterhouse, was quite rotten and was cut out. This allowed us to join the new deck to the old in a well-staggered butt pattern. Once this area of the deck was caulked and paid, a new sill timber was shaped and installed. With the hull planked and caulked, and the main deck laid and caulked, the funding for the project was almost gone. 21

Wedges hold the spacing of the main deck plank seams. Planks are attached with squaresection spikes set into countersunk holes. At the end of the deck, the afterhouse is now down and back in place. 2006-02-09(9)

Top: Some of the original hanging knees sit on the hangar floor, repaired and waiting to be re-installed. Most of the original knees showed some rot pockets on the upper and outer faces. They were repaired with carefully fitted inserts of fresh timber glued in place. The old fastening holes were filled with wooden dowels. New holes were drilled when the knees were finally installed. Above: The finished knees show very little of this work on their exposed faces. 2005-11-30(30) and 2006-02-14(13)

The main deck planking is largely complete, but not yet caulked or paid. The hatch coamings and bulwark planking are not yet installed. 2006-02-21(15)

We would be able to pay for painting and re-launching the vessel, but it looked like we could not afford to fund several major work items. The largest of these items was the bulwark planking (the continuation of the hull planking above the main deck level). In the end, funding for the planking came through from the 22

Regional Cultural Resources program. The bulwark planking ultimately went on in very good style. We were seriously contemplating launching the vessel without the rail cap, the 5-inch timber that tops the bulwark and lends its bit of longitudinal strength to the upper hull structure. However, the

Caulking the main deck on the port side of the afterhouse. A specialized caulking stool on wheels is used for deck work. 2006-02-21(5) SEA LETTER

decision was finally made to hold the vessel in the hangar into the 2007 fiscal year and to use Maritime Park base funding to pay for the rail cap and various other finishing projects. The Thayer will emerge from her hangar watertight and ready to float. She will, however, be far from complete. There will be no forward house, no taffrail around the stern, no fancy carved beakhead, no masts or rigging, and no internal bulkheads or accommodation decks. The diagonal pointers, the upper sister keelsons, and the remainder of the thin ceiling planks will have to be put in at a later time. She will not be properly ballasted, and will have only temporary bilge pumping and electrical systems. Yet with all of this work deferred, and the vessel only partially open to the public upon her return to Hyde Street Pier, we can still look at the project thus far with a good deal of pride. Above: Horsing the deck. 2006-04-05(2) Left: Paying the deck seams with hot marine glue. 2006-03-21(8) Below: Looking forward, the deck has been caulked and paid. The coaming timbers around the hatches have been installed, as has the bulwark planking. The rail caps are not yet installed. 2006-04-24(28)


The foredeck framing is in place. 2006-06-28(12)

The bulwarks are sanded after the initial prime coat. 2006-05-10(10)

The work that we have done is comparable in every important respect to the original construction. The process of doing the work has revealed to us secrets of West Coast shipbuilding that would otherwise have been lost to the sands of time. The record that we have created, of what that vessel is, of how she was designed, and of how she was put together, is worth 24

as much to our understanding of wooden shipbuilding history as the physical product. The opportunity to work with these magnificent sizes and lengths of beautiful, tight-grained fir has been a gift. The experience may never be repeated. From week to week, our appreciation grew for the logic of the construction, and for the minds and hands that created it.

All painting on the Thayer was done with roller and brush for a more authentic look and texture. 2006-06-13(7)


Commemorative C.A. Thayer merchandise available at the Maritime Store at Hyde Street Pier

Members receive a 15% discount both in The Maritime Store at Hyde Street Pier, and The Pampanito Store at Pier 45 Visit the Maritime Store online at or call the store directly at (415) 775-BOOK (2665)

San Francisco Maritime National Park Association Building E, Fort Mason P.O. Box 470310 ~ San Francisco, CA 94147-0310

Rebuilding the C.A. Thayer  

Issue No.68 celebrates the years of hard work toward the restoration of this grand Pacific lumber schooner.