Shipshape

1. How to build an Anglo-Saxon ship

Paul Constantine

Having decided on the shape of the ship we have lots of drawings to record the findings. Anglo-Saxons did not do this. Our drawings will be on computers or drawn on paper with pens and pencils or on sheets of plywood with permanent markers. Anglo-Saxons didn’t have these things, so what did they do instead?. Our drawings will be explained.

Anglo-Saxons had men with knowledge and experience

They kept the images of what they wanted to build in their heads. They had been told how to make boats by their fathers, their granddads and their friends and workmates. They learned by doing the work. We call this method of passing on information word-of-mouth, or rules-of-thumb.We say that this is an oral tradition.  The iknowledge they shared was about related proportions – If a boat is ‘this’ long, then it should be about ‘this’ wide and about ‘this’ deep. The amount of wood and the sizes of the wood to make any boat were known. The many different skills were understood and there would be men ‘expert’ in each of the processes needed to produce the materials, transport them and assemble them. There are many parts of the world where this still happens today, where large wooden craft are built on open beaches without a drawing in sight, by people whose families have constructed boats for generations.                                         Pictures taken from the film The Vikings                                                                                                                                                                                            with a small craft under construction.

Why don’t we do the same?

We don’t have their experience. They had built hundreds of boats, not just one. Our modern craft are now made from different materials. They had the timber available and they could change the construction as they went along if they wanted to. We cannot change anything. We are trying to copy their craft that we found, as exactly as possible to learn from the process. They weren’t copying they were constructing using the timber they had. This leads to many differences between our process and theirs. They tried to be ‘roughly’ accurate, so if something was half an inch or an inch too big or too small, (they used imperial sizes on this craft) it didn’t matter a great deal. We are trying to be ‘precisely’ correct attempting to get millimetre accuracy which might have seemed strange to them.    The construction is genuine with                                                                                                                                                                                    overhead bracing supporting the structure.

The King’s Orders

The king would have had his own craftspeople ready to produce any of the things that were needed in his operations. We know from the Anglo-Saxon articles that have been discovered that these people were incredibly skillful. Their metalwork and precious objects show wonderful artistic judgement and the finest workmanship that can hardly be repeated today if we use only the tools that they had.

The king would decide that he wanted a ship and that it be grander than any other ship possessed by his neighbours. He would call upon his shipwright to make the ship and they would discuss how possible it was to make the craft. How much wood would it take, how long, how wide, how fast it would be and where could it go? How long would it take to build it, how many men would be needed to construct it and then to man it? It would be a big project involving the whole of the community and be very costly, rather like building and running a major warship today. Not every group could afford it then, and not every nation can afford to do it now. Obviously you could not build a warship today, but do not underestimate the effort and complexity of constructing this ship. If YOU were asked to build a 27metre wooden ship to be propelled by 40 people could you do it, today? You have an axe – go and DO it! Only when you are in this situation do you begin to appreciate the enormity of the task.

                                                                                                                                                                          Paul Mortimer dressed in the

                                                                                                                                                                          authentic replica clothes of King Raedwald.

How were boats ‘designed’?

The King’s shipwright would have gathered his men together on the beach and scraped a straight line the length of the ship into the sand to represent the keel. Half way along it another line would be drawn at 90 degrees across it (see below). This is the midway or midship frame showing the width or beam of the craft. Using a flexible batten, curving lines could be scraped from the end of the keel out towards the ends of the beam, to show the shape that a seagull might see flying over it. This is the plan view of the ship. At this point the curves could be discussed by sighting along them and moving them in or out a little at different points. It is only strictly necessary to do this for one side of the ship as the other side will be made as a mirror image of the side being discussed. The men perfectly understand the effects of making the ship narrower, or more pointed, wider, or with more rocker. They would be discussing its speed, its ability to carry weight, how it will lift to waves, or how shallow its draught may be and how easy it will be to run it up the beach.

       When they were happy with the blend of all their compromises they would return to the midship frame and make another scape in the sand to show what shape it would be. Again, the shape is discussed to decide how deep it is, how flat the bottom, how curved the sides, as they consider where any deck might come, where seats will be placed and how stable the craft will be. When everything was decided and the shipwrights were happy, they could begin.

This is an age-old process and has been used within my memory to ‘design’ commercial, inshore, clinker fishing boats locally. The boats being built were usually a modified version of another boat already in use; a bit wider, a bit shorter or fuller in the bow or stern.

 

Setting out the ship

The shipwright had to set out the line of the keel and it had to be straight. How did he do this? Simple really, he had a long string line and a couple of pegs. Secure one end of the string with a peg, stride out the length and attach the string to another peg. Strings and pegs were the essential tools

The measurement units used were most probably Roman, as explained by Paul Handley the Naval Architect.

 

'Measurements of the frame positions taken from the plans showed that the average frame spacing, ignoring irregular spacing at the ends of the boat, was very close to 3 feet (2.994 ft average). (One Roman foot = 11.6 imperial inches, slightly shorter than a modern foot PC.)

This 3-foot frame spacing may be coincidental, but a review of measurements used in Saxon times for land buildings indicated that it was likely that there were two measurement systems in use at the time.

One was based on a ‘rod’, which was 15 German feet long with each German foot 13.2 inches long, so the German rod was 16.5 modern feet long. The other was based on Roman units where a ‘rod’ was 15 feet long with each foot about 12 inches long, these feet and inches being a similar size as modern imperial units.

It therefore seems a reasonable assumption that the Roman/current imperial measurement system was used for the Sutton Hoo ship, particularly when further noting that the overall distance between the end-most frames is 75 feet or 5 ‘rods’.

Also, that the average planking thickness is 1 inch based on measurements taken from plank scarf join rivets. And while it could be coincidental, it was noted that the average width of the hull planks in the mid sections is approximately 1 ft.

If this measurement system assumption is correct, then it would suggest that there has been no significant expansion or contraction of the ground over the 75 ft length between the end frames, and that the overall dimensions of the impression may be considered very accurate, perhaps more so than the dimensions of preserved historic wooden ships where timber distortion and shrinkage can lead to considerable speculation over the original ship dimensions and shape, as is the case for the Nydam ship.' (P. Handley Historic Ships Talk to R.I.N.A. December 2016)

 

Setting out using string lines and pegs is still used today, especially for buildings and brickwork. They check for straight lines, but they can be used for many geometric constructions when they are used like a very large compass (see diagram above). The Greeks and Romans were masters of geometry for structural work and the Roman dimensions are another indicator (with rib-to-plank attachment) of this ship being built in this country.

  • Locating the midship position and ensuring the frames were at 90° to the keel would use string-and-peg geometry.
  • Understanding the rigidity of the triangle and producing a right angle using 3-4-5 lengths was all fundamental knowledge for the builders.
  • Using marked sticks for repeated measurements meant that measurement errors were reduced to a minimum.
  • Upright components would be checked with plumb bobs, which are simply weights on string.
  • String could be made from hand-twisted plant fibres. The Hjortspring boat 325BC (Investigation 3c) was tied together with lime-bast rope made from the interior bark of the lime tree.

 

How do we make drawings of boats?

Following extensive research, the Naval Architect makes the drawings.

One drawing (right) looks like the ship is coming towards you from the front, but actually, it is coming towards you on its LEFT side, and going away from you on its RIGHT side, as the curves are not the same on both sides.

These curving lines are the shape of the ship at different places all along its length.

Each curve is then numbered, because they coincide with the ribs of the ship. As there are 26 for this ship, number 13 will be the midship curve, also called a section. The curves gradually change shape as they move towards the bow or the stern. The curves are drawn on a grid (below left). The lower horizontal lines are called waterlines. The curves are then numbered. Numbers 1, 2, 3 are at the bow and 24, 25, 26 are at the stern. A measurement scale is added to the drawing. In the example (right), just the bow sections are drawn and one section at number 8 is indicated.

 

 

A view of the side of the ship shows where the frames are to be positioned. (P.Handley)

If the shape of each frame is copied (top right in left picture below) and then slotted onto the side view of the ship, as in this model (5th Woodbridge Sea scouts), the form of the ship can be seen. This is how the ship can be visualised. All that remains to be done is to make the frames full size instead of to scale.

 

 

 

 

 

 

 

 

 

 

 

 

 

Now that we have an understanding of the process, we can look at the making of that single frame Number 8 almost as the Anglo-Saxons would have seen it.

Shipshape 2 is coming soon