Joe Startin speculates – Did she sail? Part 3

Sae Wylfing - the half length replica of the Sutton Hoo Ship

Opinions about whether or not the Sutton Hoo ship sailed differ between sailors and non-sailors.  It is difficult for the sailors, whatever their views, to avoid patronising the non-sailors.  Only practised sailors, they will suggest, can understand such things as: the forces on the mast, the stays, the shrouds and the rudder; the significance of a keel, leeway and ‘weather-helm’; the fore and aft position of the mast; the usefulness of being able to sail just that bit closer to the wind; and so forth.

With a following wind , the ship can easily move forward in response.  It can quickly get up to speed without large forces on the rig.  The ship is designed to move in that direction, with the minimum drag from the water.  Once moving with the wind, the force on the sail will diminish, and there will be even less strain on the rig.

When the wind is from the side, the forces on the rig are much greater.  The ship presents a long side to the water, and naturally resists being pushed sideways.  The windward shrouds – the lines from the windward side of the hull to the upper parts of the mast – tighten.  The large force from the wind makes the ship heel.

The effect can be seen in this picture of a modern yacht.

A sailing boat heads towards the lighthouse at the end of the Needles rocks on the Isle of Wight, Hampshire, UK.

The sideways movement of the hull is resisted by a reaction force from the water.  These two large forces, from the wind and from the water, largely oppose each other.  They strain the ship internally, but for the ship as a whole they largely cancel out.  There remains a small net force that moves the ship forwards.

The rig imposes forces on the hull.  One end of each windward shroud is trying to tear itself away from the ship’s side; the other end is pulling the top of the mast downwards, resulting in a large compressive force through the mast into the bottom of the hull.

For the reconstructed Sutton Hoo ship to withstand such forces, the hull would have to be strengthened, and the downwards point force from the bottom of the mast would have to be distributed.  We have no clues from the 1939 remains how this might have been done in the original ship, if it was done at all.  The bottom of the central part of the ship was obliterated by the burial chamber, no fittings for shrouds or stays were seen, and none of the thwarts or their supports were found.

Sutton Hoo ship plan of mid-ships section looking forwards

Some people used to say the ship could not sail because she would just skid sideways over the water.  There is no keel to ‘grip’ the water.  But the side of the hull does offer a lot of resistance.  Look at the 2018 drawing, imagine some heel, and judge for yourself.

More depth to the keel might help, but it is not essential.  That is the point that Edwin Gifford wanted to make with his half-length replica, Sae Wylfing – the photo at the top of the post shows her profile.

To be continued………..