The Khufu solar barge c. 2,566 BCE - a cross-section model, scale 1:10 by Dan Pariser

[shipmodel]

Some thoughts on the construction of the Khufu solar barge derived by building an accurate scale cross section model.

By Dan Pariser

 

   First, thanks to all who have followed me from my prior build log of the SS Mayaguez.  Thanks as well for all the likes and comments and suggestions that this community provided on that project.

   As will be seen, this project is based on information, plans and drawings which have much less precision and certainty than when I was building that modern steel-hulled ship.  I invite and request that all of the readers of this log give me their comments and suggestions to improve the model and keep me from going too far astray.

 

Part 1 - background and research

 

     Ancient civilizations have always fascinated me, especially Pharaonic Egypt, whose culture and religion were so focused on death and the afterlife.  Other early peoples were certainly focused on death, mostly the death of their enemies in war, but this one was all about their own deaths.  Strange.

   

     Somehow though, this philosophy led to some the greatest architectural, engineering and artistic works of the dawn of history.  This was true in shipbuilding as well.  Since the land is dominated by the long, straight river Nile, boats were incredibly important to move people and goods up and down its narrow fertile valley.  Boats of all types are depicted on the walls of tombs and were taken into the afterlife as models which would magically become real for the use of the deceased when the right spells and chants were said. 

 

   One of the oldest of these, and the best preserved, is the solar barge or funerary boat of the Pharaoh Khufu, also known as Cheops, the builder of the Great Pyramid at Giza.  (Figure 1) He wanted to take it with him into the afterlife, not as a model, but the actual boat.  To do this he had it fully built and then disassembled and buried in a sealed underground limestone crypt (Figure 2) next to his pyramid where it remained from about 2,560 BCE till being discovered in 1954, a span of over 4,500 years.  Yet because the seals had not been broken the wood was still in remarkably good condition. (Figure 3). 

   A team led by Egyptian archaeologist Dr. Hag Ahmed Youssef Moustafa spent 13 years putting back together its more than 2000 pieces.  The fully assembled boat was displayed in its own modern purpose built museum next to the Great Pyramid (Figure 4).  It has recently been moved to new quarters with better air conditioning in the Grand Egyptian Museum in Cairo.

 

   The saga of the discovery and reconstruction has been documented by American historic marine construction expert Paul Lipke (Lipke) based on over a hundred hours of translated interviews with Dr. Moustafa and hundreds of photographs and drawings of the boat and its parts made during the reconstruction. (The Royal Ship of Cheops, British Archaeological Reports, 1984).   His fascinating and comprehensive report is mandatory reading for anyone interested in this iconic craft.  He reproduces dozens of photographs of the reconstruction process and gives precise measurements for many of the boat’s details.  He also drew preliminary scale plans of the boat. (Figure 5).  

    Many additional photographs can be found in the book, “The Boat Beneath the Pyramid” by Nancy Jenkins, another must-read source, while other drawings and plans were developed by famed marine archeologist Bjorn Landstrom in “Ships of the Pharaohs”.  The final source that was central to this article is “The Construction of the Khufu I Vessel (c.2566 BC): a Re-Evaluation” by Samuel Mark (Mark) of Texas A&M University, published in the International Journal of Nautical Archaeology (2009).

 

     From Lipke’s initial plans and measurements various drawings have been created of the boat which give a better idea of its particulars. (Figure 6).  As you can see, the boat itself has a striking shape.  It is quite long at 43.6m (142 feet), but with a breadth of only 5.9m (19 feet) at its widest point.  Its shallow draft is only 1.78m (6 feet) from keel to sheer, with a freeboard from waterline to sheer of less than a meter.   The boat tapers symmetrically to points at both ends which curve up high above the waterline with carved ends that reflect the shape of papyrus reed boats from the dawn of Egyptian history.  On deck is a lightly built deckhouse which may have housed the Pharaoh’s coffin and a small open altar near the bow.

 

     Its construction is unusual to us as well.  Hull planks, 12cm (5 inch) thick, are fitted to their neighbors with mortice and tenon joints.  The planks are then laced to each other with ropes that snake through “V” shaped tunnels chiseled into the interior faces of the planks.  Rounded battens cover the plank seams and are held in place with the same lashings. (Figure 7).   Multiple beams span the hull from sheer to sheer, locked in place and strengthened by two notched side stringers above the beams and a central spine below.  The central spine is supported on short stanchions which rest on frames which spread the deck loads to the bottom planks.  These too are held in place with rope lashings. (Figure 8).   Taken together, the wooden pieces and lashings form a truss structure which would have been quite strong and rigid.

 

     However, these cross sectional and perspective drawings are somewhat simplified and stylized.  There are also two cross section models that I know of, but they are also similarly simplified, although the one built for Texas A&M University is quite accurate in its general configuration. (Figure 9).  This is perhaps because no one has been able to accurately measure and draw plans based on the actual ship.  Even the plans drawn by Lipke were derived from a 1:20 scale model built by Dr. Moustafa to aid his reconstruction work. 

 

    Compared to photographs of the boat’s interior, the profiles in the drawings and the model are too high and steep, the planks are too regular, the battens covering the plank seams are too narrow, rounded and straight, the lashings are too regular, and the tunnels that the lashings go through are not accurately represented. (Figure 10).  Because of this, certain conclusions about construction methods and sequences have been made which are, in my opinion, somewhat inaccurate.

     I decided to attempt the construction of a precise scale cross section of a specific location in the boat to see if I could replicate a workable method and sequence for how it might have been built.  I also resolved to build it as was done by the Egyptians, with mortice and tenon joints, rope lashings, and, most of all, no other fasteners or glue. To do this, instead of relying on the prior drawings I went back to the original boat. 

  

     Although I have no access to the boat itself, there are photographs of the exterior planking and interior structures which are reproduced in the several sources mentioned before, as well as on the internet.  I am also indebted to Mr. Lipke who kindly provided me with others from his personal collection.  Then there are the drawings created by Dr. Moustafa from the boat pieces, as reproduced by Lipke and Mark.  Though many are noted as not being to scale, they are the closest to accurate drawings as can be found.  Wherever there was a conflict between the photos and the drawings, I went with the photos.  Finally, there are drawings on contemporary tomb walls showing boats under construction, as well as academic studies of contemporary boats which also informed my investigation, and which will be referenced later.  These were used a supplements to the first two.

 

     From these I selected one photograph which contained many of the construction details that I wanted to recreate.  Here is that shot, an interior view of the hull taken during reconstruction. I call it my Primary Photograph. (Figure 11). Contrasted with the simplified drawings and models, it shows planks of various widths and shapes, lashing holes in irregular patterns, and flat battens which are pieced together from short sections with angled ends.  Note the large triangular batten piece to the left which must cover seams between several planks. 

   

   Based on the photo I decided to build out the model from the line of lacing in the foreground to just beyond the dark frame, which would then include the large square batten pieces tied with crossed ropes that are sitting just in front of the frame. This would give the model sufficient visual interest for the viewer yet still allow my close adherence to traditional building methods.  

 

     Next time, the development of the working drawings.

 

     Be well

 

     Dan

 

    

[Jack12477]

I'm in, Dan ! 

[thibaultron]

I'll be following! Great research.

[mtaylor]

Fascinating.  I'm also in, Dan.

[druxey]

This is well worth looking forward to, Dan. Thanks for sharing your process.

 

I note the difference in mortices for the lashings between the battens on the ship itself and the cross sectional model. the lashings just appear and disappear again.

[shipmodel]

Hi all - 

 

Glad to have you along for the journey.  It will be a work in progress, both the writing and the building.

I have just hit a snag, though.  Not with the building, but with the writing.

I have tried to use only open-source photos and drawings, but the technical drawings from Lipke and Mark are under copyright.

I have contacted them and I expect permission soon, but I can't post my next segment until I do.  

 

Happy Thanksgiving to every one, American or not.

 

Dan

[shipmodel]

Hi again to all - 

 

Thanks for the likes and interest.

 

My next segment was going to be the development of my scaled and measured working drawings.  For the illustrations I need to include the copyright materials, for which I have only partial permissions.  So instead, this will be part 3, a discussion of Egyptian construction methods, moved up to part 2.  The sequence numbers for the images are therefore out of order, but they are all from open source websites.

 

Before cutting wood, I wanted to look into historic Egyptian shipbuilding.  I made a commitment on this model to build it by relying on the original Egyptian techniques, at least as closely as possible for only one workman building a miniature.  So here is a quick dip into the original techniques might have been in use at the time that the Khufu ship was built. 

 

I was fortunate in this regard with information from a remarkably preserved tomb which has a series of wall carvings that show boats under construction.  In the cemetery at Saqqara is the tomb, or mastaba, of Ti (or Ty).  He was a long serving senior official and royal architect during the Fifth Dynasty, only 100 years or so after the Fourth Dynasty, the time of Pharaoh Khufu.  The tomb was discovered in the late 1800s by French archaeologist August Mariette and has some of the best bas-relief carvings of daily life from Egypt’s Old Kingdom.  In one of the outer chambers is a unique carved wall showing five boats under construction and two side panels with men working on planks for the boats. (Figure 21). 

 

It is a shame that I could not find a color image of the wall, just some smaller sections, since the carvings and even the polychrome pigments have survived for all this time. (Figure 22 – ti wall detail).  

 

Ti is known to have been in charge of the decoration of the tombs of several Pharaohs, so he must have had a long career where he was perfectly placed to assign the best craftsmen to work on his own tomb.  In this close-up you can see that even individual fingers were delicately carved.  You can certainly see what the workmen are doing and the strange tools that they are using.  (Figure 23 – using adzes)

 

Here are a selection of the actual tools.  At the top is a large axe, with two different saws below it, while at the bottom left are several small awls and chisels.  In the middle is a bent wood bow for a drill.  The largest tool, the one the workmen are using, is an adze, like a plane blade mounted on a bent handle. (Figure 24 – tools).

 

In Figure 23, above, three workmen are using adzes to trim wood and to smooth the outside planks of the hull, a technique called dubbing that is still used today.  The quality of the carving is so high that you can see the subtle differences in the shapes of the adze handles to do the two different tasks.  In the hieroglyphics there are representations of several tools.  Above the upper worker is a short handled axe, a hatchet.  To the right of the feather is an awl or chisel.  Maybe the rest of the symbols are talking about that tool, but I have no idea.

 

In the next scene a man is doing some sawing with a weighted stick and rope that is holding the kerf in the workpiece open (or closed, it is not clear).  Two others are sitting on an upended plank and chiseling mortices into its edge.  Above them seem to be carved images of the two types of saws and another chisel. (Figure 25).

 

In the third detail image the first man is, I believe, using a two-handed sledgehammer.  A similar type of hammer is still used to drive in fence posts.  The second man, who seems to be left-handed, is holding an awl or a marking tool, it is impossible to tell.  In the carvings the only thing that might be a tool is the twisted rope at the top left.  But what the paired faces of the monkey and Alfred E. Newman are supposed to be saying, I truly have no idea. (Figure 26).

 

What does all this mean for my project?  That the ancient Egyptians built their boats with the same techniques that we would use if all the electricity were turned off.  They were not stupid or unsophisticated, and didn’t need the help of aliens to build boats or pyramids.  I feel confident that my use of similar techniques, but with a few power tools, will not compromise the historic accuracy that I am working to achieve.

 

More soon when I can post drawings.

 

Be well

 

Dan

[shipmodel]

Hello again to all.  I trust that my fellow Americans all had a good Thanksgiving with family and friends.  Now that my tryptophan coma has abated, it’s back to the ol’ computer.

 

I have received permissions to reprint drawings and photographs from my primary sources, Paul Lipke and Samuel Mark, so this build log can go forward.  I am deeply thankful to them for their courtesy and encouragement.  I am still waiting for the same from Nancy Jenkins’ publisher and from Dr. Cheryl Ward Haldane, whose work I also am relying on, but to a much lesser extent.

 

When section 1 left off I had identified the area of the boat that I wanted to model.  This was shown in the Primary Photograph taken during the boat’s reconstruction.  (Figure 11). 

 

The first task was therefore to determine exactly where this section of the boat was located.  Because the plank edges are covered I went to a drawing of the batten patterns originally created by Dr. Moustafa, reproduced by Lipke and then cleaned up and sharpened by Mark.   This is the common derivation of many of the drawings that I am using.  (Figure 12 – batten pattern). 

 

Although not precisely to scale it is accurate enough to use for this purpose.  Comparing plank and batten shapes, especially those large batten pieces, the only location which fits all the details starts near the bow end of the three center bottom planks.  For ease of comparison I have abstracted and rotated the section that I believe matches the photo. (see insert).  The model will therefore be a recreation of the slice of the hull between the red lines.

 

To develop working drawings of this area I turned to my good friend PhotoShop.  Using its expansion function and its rulers and guidelines, I could resize the drawings of the overall boat until they read as 43.6 meters long and 5.9 meters breadth.  I then took the batten pattern with the selected area and resized it to those overall drawings using landmarks such as plank shapes and joints to make them match.  Finally I took the most detailed plank expansion drawing made by Dr. Moustafa (as redrawn by Mark) and matched it to the prior two drawings.  The resulting multiple image made it easier for me to understand exactly what I was attempting. (Figure 13 – multiple sized drawings). 

 

It turned out that my selected area was located just forward of midships, with its aft edge a bit wider than the fore end.  It was also almost exactly 3 meters long, so I adjusted my design to fit that dimension.  This turned out to be a fortunate decision, as will be seen.

 

Another plank expansion drawing that was of great help was also created by Mark based on Lipke’s work. It is much simplified from Mustafa’s drawing and, although not to scale, shows some details more clearly.  (Figure 14 – Mark plank expansion). 

 

From the two plank expansion drawings I marked out the appropriate sections of the planks, cropped them from the larger drawings, enlarged them, rotated them, and matched them to each other.  Now I could get a more complete idea of the sizes and shapes of the plank sections that would make up the model. (Figure 15 – model planks). 

 

Close examination of these drawings also gave me information on several construction details that will be incorporated into the model.  First, the many rectangular marks on the planks in Moustafa’s drawing represent the ‘transverse lacing holes’ for the lashings that go from sheer to sheer.  They do not exactly match their sizes or locations as seen in the Primary Photo, but they are close.   As before, where there is a conflict between drawings and photographs, I go with the photos.  Second, the tenons between the plank edges are shown as small tabs on the sides of the planks (for the central three bottom planks the tenons are not indicated on this drawing, but they are on another of Mustafa’s plans). 

 

In Mark’s drawing, first note that most of the planks have notches, or joggles, that fit to the neighboring plank.  These would have prevented the planks from sliding past each other and would have given a great deal of lengthwise rigidity to the hull.  Second, in this drawing the rectangular marks give the locations of what have been called ‘strategic lacing holes’ to distinguish them from the ‘transverse lacing holes’.  Much more on these later.

 

Now was the time to decide a thorny philosophical question:  how much accuracy should I aim for?  The drawings are only accurate for a given value of ‘accurate’; they are not modern engineering blueprints.  Should I try to replicate every bump and irregularity of the planks in Moustafa’s drawing, or go for a smoother, simpler build closer to the look of Mark’s drawing.  I have to confess that I finally went for the simpler construction.  Not only would this speed the building process, but it may even be closer to the shapes that the planks had originally before they sat and warped for 4,500 years. Nonetheless, I will strive to make the model as true to the original boat as I can envision.

 

What scale should I use for the build?  It had to be selected so the model is not too small to reasonably build the fine details, yet not too large to make it unwieldly.  I started with 1:20, the same scale as Dr. Mustafa’s model, but the test model that I built proved too small to allow me to easily cut the hundreds of tunnels into the planks.  It taught me many important lessons, but ultimately had to be abandoned. (Figure 16 – small test model).  

 

I considered 1:15, which would have meant converting dimensions for each piece, and even 1:12 if I wanted to convert from metric dimensions to Imperial ones each time.  Both of these would involve lots of calculations which I could get wrong.

 

Ultimately, although it would make for a larger model, I settled on 1:10.  Since Mustafa, Lipke and Mark all use metric measurements, conversion would be a snap.  The overall size of the model will therefore be 59cm from sheer to sheer, 17.8cm bottom plank to the sheer, and 30cm front to back (23” x 7” x 12”).  This is, I believe, the same scale as the Texas A&M model.  It should make for a model with a considerable amount of detail, but one that can be easily viewed and understood.

 

Now the actual dimensions to cut each piece had to be established.  Only that one drawing of the planks has any measuring scale, and I understand that this was added after the drawing was made and, in any case, Mustafa did not want it published.  I therefore used it only for limited purposes and did not rely on it completely. 

 

Instead, I took all of the scaled and expanded drawings and compared the dimensions for the forward end of the combined three center planks.  Using not only the scale on the drawing but also my PhotoShop rulers, I got a pretty consistent width of 180cm.  Now to determine the size of each of the three planks.  Going back to the Primary Photograph I compared the width of each plank to the others, measured directly from the image on my computer screen (assuming that the plank edges are centered under the battens).  The ratio turned out to be four width units for plank 1, two units for plank 2, and three units for plank 3.  So if 9 width units equals 180cm, each unit is 20cm.  Therefore plank 1 is 80cm wide; plank 2 is 40cm; and plank 3 is 60cm (Figure 17).

 

I expanded the photo image until the PhotoShop rulers gave those same dimensions.  Now I could directly measure details in the photo.   The first was the size of the battens covering the plank edges.  From the photo I measured widths of between 15 and 17cm.  I will incorporate some variation, but I used 16cm as my basic width for the battens on the model.

 

Next was the spacing of the transverse lacing holes.  Looking at the patterns of holes it is obvious to me that they were chiseled in pairs (being the ends of the lacing tunnels in the planks).  They form double lines with the outer holes closer to the edges of the planks and the inner ones a reasonably consistent distance inside them.  Lipke records that the holes are spaced an average 10cm apart.  I don’t know what or where this was measured, but it doesn’t quite match the dimensions in the photo.  It may be that for these first planks the tunnels were a bit longer.  However, as before, where there is a conflict between the photographs and the written dimensions, I go with the photographs.  Directly measuring these holes I get a distance of 13 to 15cm between pairs, so I chose to average this to 14cm, and this is the dimension that I used.

 

The next question was - where are the lines of holes located in relation to the edges of the planks which are hidden by the battens?  Using 16cm for the width of the battens and adding another 5cm for the outer holes to clear the sides of the batten, this means that the outer holes will be located about 13cm from the edge of the plank, which matches several of the measured distances.    

 

The lacing holes are also important to determine the plank shapes.  If the double lines of holes are a set distance from the plank edges, then the distance between the two lines becomes a variable dependant on the shape of the plank.  If this distance is consistent, then the plank edges are parallel.  Based on this, Plank 1 has a consistent width, since the space between the inner holes does not seem to change.  Similarly, Plank 2 is also of consistent width although only half that of Plank 1. 

 

Plank 3, however, widens gradually as it moves away from the camera.  At the near end there are only three holes in the line running across the plank where the lacing is (for clarity I am calling this transverse line of holes a ‘set’, whether across one or multiple planks).  The three hole set at the near end of the plank is created when the plank is narrow and the inner holes of two lacing tunnels merge at the same spot.  But the lines start to diverge and by the fourth set there are four distinct and separate holes.  By the tenth set (seen just under the frame), the four holes are equally spaced across the plank, a gain of approximately 14cm.  This happens as the boat’s breadth widens toward the midships point.

 

How far apart are the sets of holes?  Lipke reports that they are approximately 25cm apart, a dimension which I adopted.  Now the fortunate decision to make the model span 3m of the boat came into its own.  With this spacing there will be 13 sets of holes with 12 spaces between them.  The two sets at the ends will be only half sets and will be open on the edges of the planks to show the construction of the lacing tunnels and mortice and tenon joints.  Sweet!

 

How large are the holes themselves?  They are recorded as being 7cm long and 1.5cm wide.  This would be reasonable for tunnels that would receive lashings of 5 ropes, each of approximately 1cm diameter.

 

A note here about dimensions.  The ancient Egyptians relied on measurements taken from the human body.  The average hand provides several of these.  If their hands were similar to mine, dimensions of 7cm (palm), 10cm (hand), 1.8cm (finger), and 24cm (span) are all readily available. (Figure 18).  There is also the cubit, known from Noah’s ark, which is the distance from the tips of the fingers to the elbow and estimated to be 50cm.  All of these could be quickly used by the workmen to mark out the hole locations.  Of course having some sort of simple ruler or measuring device is too obvious to ignore, but it was likely based on the hand dimensions as well.

 

Merging all of this information I developed a measured construction drawing for the three center planks. It is a little rough because it is only a working drawing, but the measurements are accurate enough to use. Printed out full size it became the pattern for cutting and detailing each plank.  (Figure 19).

 

 

I incorporated three additional details into the working drawing.  From the several plank expansion drawings it appears that there are joggles between the three planks to help lock them together.  So although the lines of lacing holes appear reasonably straight, I have shown the two joggles which will be hidden by the battens in the final model.  The locations of the eight mortice and tenon joints between the planks were taken from Dr. Mustafa’s drawing, although their size and shapes will be further examined as they come up in the building process.  Similarly, the strategic holes are located as indicated in the drawings but their details may be changed during construction.

 

At the bottom of the drawing is a cross sectional sketch of the plank ends.  The lacing tunnels and mortice locations are marked in grey.  I imagine that the sides of the tunnels would have been chiseled out from both directions at around 45 degrees, thus meeting in the middle approximately 6-7cm below the face of the plank.  The merged tunnels of plank 3 create the 3-hole set seen in the Primary Photo. It is also clear that the mortices, if cut into the edge of the plank at about mid-thickness, never come near interfering with the lacing tunnels or weakening the plank. 

 

The outer edges of planks 1 and 3 are beveled to accept the garboard strakes.  Lipke records the angle between the center and garboard planks to be 40 degrees, so the bevel was carved to 20 degrees, and the same will be done for the edge of the garboard.

 

I know that I have used straight lines in several places where the photo shows slightly irregular and meandering lines.  I will be cutting and chiseling the wood by hand, so there will be some variation built into the construction process, but I do recognize that I have simplified the model a bit.  Hopefully, not too much to make a major difference to any conclusions that I may draw from building it.   

 

With this drawing in hand it is finally time to start cutting wood!

 

More soon.

 

Dan

 

[druxey]

A lovely methodic approach, Dan!

[Reverend Colonel]

Great idea! Im excited to keep reading and watch your progress. 
J

[shipmodel]

Hello again to all.  Thanks for the likes and ‘wow’s.  They are always very encouraging.

 

Cutting and fitting the first three planks –

Now with the working drawing in hand (Figure 19) I started butchering wood.  These will be the first of 17 planks, large and small, that will make up the model.  They are the bottom planks of the boat and take the place of the keel, so I wanted to get them right.  I printed out the drawing full sized and cut out the three plank patterns, then affixed them to 12mm thick basswood planks with spray mounting adhesive.  The planks had to be cut separately so I could get at the joggles with my saw. (Figure 27)

 

I carefully cut them out on the band saw and matched the joggles to their partners. (Figure 28)

 

The fit was checked by turning them over to see the gaps between the planks.  These were reduced by hand sanding until there was a tight fit. (Figure 29)

 

Mortice and tenon joints - 

Edge joining hull planks with mortice and tenon joints has been a common feature of ancient shipbuilding almost since boats have been built.  They have been found in Greek and Roman ships, and even up to later European 15^th century ships.  Egyptian examples are scarce, but all include this feature, although with variations. 

 

The closest Egyptian boats to our subject that have been discovered to date are the five (or six) small boats excavated near the pyramid of Senwosret III at Dashur, just south of Giza, and date from around 1850 BC (six hundred years after Khufu).  In addition there are several planks for a small boat found at El-Lisht dating from around 1950 BC.  All of them have large tenons measuring about 20cm long, 7cm wide, and 1.5cm thick.  They are also tapered towards their ends so they are lozenge shaped.  (Figure 30 – Dashur m/t drawing).

 

 

The mortices are cut a bit wider than the tenons, but are tight to their thickness.  As a shipwright I suspect that this extra width as well as the tapered shape was so that the tenon would be more easily inserted and re-inserted during construction where the plank might have to be repeatedly offered to its neighbor for trimming and alignment.  Shims along the sides of the tenons, and even adhesive putty substances have been found, which may have temporarily held the tenons in place during construction.  This design would have allowed some lateral movement for adjustment, but would resist any vertical movement of the planks relative to each other.

 

The mortices were chiseled along the centerline of the plank edges, as seen in the wall art of Ti (Figure 25, above).  Some additional mortices were also cut, perhaps for strength at critical points.  In this view of a plank from a Dashur boat now located at the Carnegie Museum of Natural History in Chicago, you can see three mortices, one with a replacement tenon inserted.  Note that the openings are wider than the marked sizes of the mortices, and there is even one which shows a crushed corner from the shaft of the chisel that cut it.  For clarity I have outlined the approximate plank edges.  (Figure 31 – Carnegie mortices). 

In the Khufu barge the tenons are shaped from sidder (Ziziphus spinachristi), a local hard and durable wood, but suitable only for small items as the branches are quite narrow.  They are set about 90cm apart along the length of the longest planks such as the four garboard strakes, as measured on Mustafa’s plank expansion drawing (see, Figure 13 above).  However, this is not a fixed dimension.  The 14 tenons along the forward starboard garboard plank actually vary from about 70cm to 130cm apart.  In other locations there are multiple closely spaced tenons where planks scarf or butt to each other.  This leads me to conclude that they were placed where needed rather than using a rigid spacing scheme. (Figure 32 – tenons in use).

 

The tenons of the Khufu boat are substantially different from the Dashur and Lisht tenons.  Although they are similarly 7cm wide and 1.6cm thick, they are only half the length, measuring 10cm rather than 20cm.  This means that only 5cm (2 inches) fit into each mortice.  I was concerned that such short tenons could slip out of the wide mortices if the planks shifted laterally.  A scale drawing shows that with a 7cm tenon in a 9cm mortice this could happen fairly easily. (Figure 33).

 

However, going back to Lipke’s writing, I found that he notes that there were two sizes of tenon found with the boat.  The first was the one already mentioned.  The other was the same length and thickness, but only half the width, at 3.5cm rather than 7cm.  Dr. Mark also went back to Lipke’s notes, photos and drawings and found that these narrow tenons were inserted across the grain of the plank edges rather than along the grain.  These, along with the plank joggles, would have significantly limited any lateral movement of the planks against each other and probably eliminated any possibility of the tenons coming out. (Figure 34 – two tenon types).

 

Using Lipke’s information, Dr. Mark went back to the plank expansion drawing and cleaned it up by removing the marks of the transverse lacing holes to more clearly show the locations of the two tenon types.  He indicates that the narrow cross-tenons only start with the third planking strake of the five side strakes.  Happily, therefore, I will not have to worry about them until later in the building process. (Figure 35 – Mark plank expansion w tenons).

 

Cutting the mortices on the model started with marking out the locations on the plank edges.  A compass was used to find and mark the centerlines of the plank edges, then 7mm widths were marked at the mortice locations taken from the various plank expansion drawings. Matching planks were clamped together so the locations could be easily aligned.  (Figure 36 – mortices marked.)

 

Mortices were drilled and chiseled 5mm deep into the plank edges using 1.2mm (.045 inch) bitts.  They were widened as needed to accept tenons of cherry wood 10mm x 7mm x 1.6mm which fit snugly into the mortices. (Figure 37 – tenons installed).

 

Tenons were inserted into mortices along the sides of the outer planks and aligned with the mortices of the middle plank. (Figure 38 – tenons aligned).

 

The three bottom planks fit together well and securely with the tenons installed.  The planks ended up flat and level with each other.  No glue or other fastenings were used so the planks could be separated and worked on individually.  (Figure 39 – planks together).

 

Transverse lacing tunnels –

I began the process of cutting in the transverse lacing tunnels by drilling shallow holes through the paper pattern at the corners of the lacing holes.  (Figure 40 – holes marked).

 

With the pattern removed a series of angled holes were drilled from both directions that, hopefully, met in the middle under the surface of the wood.  The depth of the holes was controlled by making a mark on the drill bitt that corresponded to the length of half the lacing tunnel.  When I got the distances right I could feel the drill find and slide into the hole coming from the opposite direction.  (Figure 41 – tunnels started).

 

The webbing of wood between the drilled holes was removed with the side of the drill bitt and cleaned up with a flat hobby chisel down to a depth marked on the shaft.  (Figure 42 – tunnel chiseled).

 

I checked that the two tunnel halves met by shining a light into one side so I could see that they fully met.  Once the tunnel halves were cleaned out I smoothed the bottom surface with a needle file. (Figure 43 – tunnel filed).

 

To check that the tunnel was open and the bottom walls smooth I ran a curved strip of bendable brass through the tunnel.  The end was curled up and slid down one side and then it was forced to ride up the smooth opposite bottom wall.  The brass strip was moved back and forth and side to side to clear any remaining wood that might interfere with the next step. (Figure 44 – tunnel checked).

 

A strip of cloth-backed sanding paper was cut and one end rounded.  That end was stiffened with cyano for a distance of about an inch.  Once the glue was dry the end was curled like the brass strip and fed through the tunnel.  This took some gentle persuasion in most cases, but eventually I could lace the sanding strip through each of the tunnels.  The sanding strip was pulled back and forth, further opening the tunnel and smoothing the surface of the upper wall.  Most importantly it opened and rounded off the tight pointed bend at the bottom of the tunnel which would otherwise be hard to get ropes to go around. (Figure 45 – tunnel sanded).

 

Finally, each tunnel and set of tunnels was checked by running transverse lacing ropes through them.  Rather than do this with each rope individually I glued five of them together and stiffened the last inch with cyano.  The end was then curled like the sanding strip and fed through the lacing tunnels.  This was substantially easier after the tunnels had been opened and smoothed with the sanding strip.  (Figure 46 – laced tunnel set).

 

All that remains is to repeat this process over and over until each of the transverse lacing tunnels, 60 in all for the three center planks, hundreds for the full model,  are carved and laced.  I am still in the middle of this lengthy task. 

 

If anyone has any thoughts on how I can make the process more efficient or how the end result can be improved, please give me your ideas.

 

When I post again, which may be a while, I will have a photo of the progress.

 

Until then, be well.

 

Dan

[thibaultron]

Fantastic work! One thing you might consider is carving out the edge of a plank to show one of each type of tenon in place, just for everyone to see the complete construction methods employed.

[shipmodel]

Hi Ron - 

 

Yes, a good idea.  There will be a few spots where I can show the tenon that goes with the grain, but I can't find a spot for the cross tenon that makes any sense once the planks are together.  I will have photos with the planks separated, but that's not the same thing. 

 

Dan