Pasaia (Basque Country)

The stem

The imposing curve of the bow of the San Juan

The profile of a ship is defined by the keel, the sternpost, and the stem. The stern of the San Juan was assembled a few weeks before, together with the rest of the transom.  Now the turn of the stem has been assembled. It extends from the keel forwards and upwards, defining a wide arch. It's made up of two timbers, each reaching almost five metres from tip to tip.

The stem has to be rock solid; it´s the part of the ship that cuts the waves and opens the sea for the rest of the ship. Moreover, the outer planks of the hull end on the stem, and it has to support part of the superstructure of the bow of the ship. Two huge oak trees were needed to obtain these two timbers.

roda del san juan museum

Assembling the stem in place

The process consists of two stages: first the lower half, and then the top half. The entire technical staff of Albaola takes part in it in some way.  There are very heavy timbers that have to be solidly joined, and they have to be perfectly aligned with the keel, so the symmetry of the hull is respected.

The keel and the stem are put together, drilled and nailed. A cloth soaked in tar is applied between the two ends of the scarph, so it will act as a gasket.

roda del san juan museum

The scarphs of the stem

The unions of the stem looks odd to today's shipbuilders, both the keel-to-stem scarph and the scarph between the two timbers forming the stem. Picture A shows what the scarphs of the stem of the San Juan look like; picture B represents a scarph made in 20th-century style-it's the result of the evolution of shipbuilding over the last four centuries. Although we know it's a better system, the replica of the San Juan will bear the same scarphing system of the original ship.


roda nao san juan museum

More pictures of building process here