The Minoans employed advanced construction methods using natural materials to create seaworthy composite ship hulls which would not be out-of-place in a modern-day marina. The construction method does not appear to have been used by, or transferred to, other thalassocracies which followed, e.g., Phoenicians. The technology represents a ‘lost art’ from before 1500 BC that would not be seen again until the 1950s AD.
The reader’s attention is drawn to a modern-day yacht and a reproduction of a Minoan hull – note the similarities. Both are: white, streamlined, and watertight.
Left; Fiberglass yacht hull today. Right; Replica Minoan ship. (Left; CC BY-SA 3.0/Right; CC BY-SA 2.0)
Construction of a Minoan Hull
A hull would first be constructed from wood to create a former. There are two methods that were known at that time, the first (used by other civilizations) was to drill and rebate wood planks to accommodate rope to hold the planks together with wedges inserted from the inside of the hull to provide tension on the rope to pull the planks together. Any gaps between the planks would be filled with flax or hemp fibers and pitch was applied to provide a watertight seal. Pitch was made from pine resin mixed with pulverized graphite from fire.
This method was employed by a reconstruction team and the crew report that the hull would creak at sea, as the planks move against one another, but it would hold together. It is not the timber frame that made the hull watertight, it is the linen cloth they applied. The reconstruction team had to make their best guess because the Minoan technology was improved over millennia, with a myriad of alterations over generations of Palace controlled shipyards.
A second method was known for hull construction: one that used strong mortice and tenon joints. But it fell out of use after this period. The abutting planks (typically cypress) were rebated to provide a slot, and a hole was drilled into each plank to be joined. A hexagonal shim with holes at the top and bottom was inserted, and a tapered dowel was inserted in each to provide a secure fixing.
This method has a distinct advantage over the first, as a tapered dowel self-centers and pulls the planks together to provide a strong joint. It is more likely that Minoan shipwrights used this method based upon the quality of their carpentry, as illustrated by the Thera tripod table, that shows a quality approaching, if not equaling, Chippendale furniture.
Joinery technique used for a Minoan ship hull (© Copyright Nik Aed) and plaster cast of the void left by a Minoan tripod table after the Thera eruption.
The secret to a superior hull was the application of linen cloth onto the wooden hull and the ‘wetting out’ of the cloth with pine resin, a natural polymer that becomes liquid above 70 degrees Celsius (158 degrees Fahrenheit) which can be pigment with powder additives (as the fresco below suggests) sealing the hull.
Section of the Ship procession fresco found in Akrotiri. (Museo Arqueológico Nacional de Atenas/ Public Domain)
It is interesting to note that Aero linen, once used in early airplane making, offers similar technical properties to modern day e-glass fiber and is around three times as strong in tension as a cotton cloth, largely due to the long staple length of the flax fibers. It is used today for bookbinding to provide a hard-wearing cover. The Minoans exported high quality cloth that is roughly the quality of fine weave Aero linen.
Hull Construction: linen cloth is laid over a wooden hull, molten pine resin applied (Colophony/ Rosin) that may be pigmented with stone powder (limestone for white, lapis lazuli for blue), this process repeated to provide a staggered many layered (5-10) strong composite hull. (© Copyright Nik Aed)
Although it is impossible to know without a Minoan wreck, it is likely that a strong thin-wall hull was employed (significantly reducing weight and materials) with potentially a secondary internal skin applied. In some respects, the use of this composite is more useful than a modern-day equivalent: a thermo-set epoxy resin. A natural composite can more easily be repaired or resurfaced with heat. In practice, placing a spear tip in a fire and applying it to the hull will resurface it to a glossy new finish.
The composite hull had many advantages over a plain wooden hull. It provided a lighter weight for the craft, hydrodynamic improvement (reduced form and skin friction drag) for greater speed and maneuverability, improved hull structural strength, and was able to withstand open sea voyages with easy maintenance and repair.
Speculation
Perhaps this innovation came about by a bowl of pitch resin being accidentally spilt on sail cloth. This advantage was likely to be controlled by the Palace shipyards and as it represents such a significant advantage it may have been a Minoan state-controlled secret.
An interesting possibility is that limestone powder was replaced with metal powders. The Minoans were fascinated with the aesthetic, which is clear from so many artifacts and pieces of art. For example, the Processional/Flotilla fresco shows the entire fleet shipshape in Bristol fashion, with wonderful decoration: it is adorned with the fastest animals of the ground, sea, and sky.
It seems likely that the Minoan Palace workshops or yard would have experimented with metal fillings from the metal workers to see if a metallic quality could be imparted to the hull. Metal fillings are produced when a hard bronze saw or file is used on a softer base metal of tin or copper. Metal fillings are used today to give plastic cast parts a metallic appearance when ‘cold cast’.
Although this may have been explored entirely for aesthetic reasons, there would have been a useful side effect if they had done so, barnacles would not build up on a copper or nickel impregnated hull, allowing for higher speeds maintained by oar or sail. The Royal Navy clad copper hulls for precisely this reason, copper bottomed ships outperformed those of another navy and this low drag performance advantage was closely guarded. Metalized nickel impregnated hulls would do the same, likely recorded as white on the fresco.
Cropped image of the procession fresco. Copper-bottomed Minoan hull? This is the only large ship in the procession fresco which is not white (40 oars). It is also interesting to note that the frame of the captain’s cabin seems to have the same coloring. That suggests that composite reinforcement may also have been applied internally and/or to reinforce, make watertight, or join other structural components. It is also interesting that the artist paints the interior of the hull in blue, ignoring the ‘Egyptian’ drawing convention that show scenes in strict side or plan elevation, rather than perspective, it is as if the artist wants to record the Minoan technology as an advantage. (Public Domain)
Wider Application
It seems strange that the Minoans don’t appear to have employed this construction method for other objects. Or perhaps they did, but the evidence is not to be found in literature or archaeology (noting they would naturally degrade over time.) However, they did exploit the advantages of material composites in shields.
Perhaps they never understood the underlying strength of the cloth/resin composite, as the resin would bond to the substrate, and they may have thought its application was limited to making large structures watertight. Today, composite parts are laid up on formers, which have a wax or silicone spray applied so that the part can be demolded (which requires considerable force).
This said, the Minoans prized beeswax in their toolbox for lost wax casting, so perhaps they may have experimented with other applications. As with so many things the Minoans did, they show ingenuity and creativity, but perhaps the next inventive steps were less obvious, and this technology was limited to their maritime pursuits: linen cloth being valuable and time consuming to spin and weave.
Nonetheless, it was an advantage: a faster more agile fleet, ships that were easy to repair and service. What must foreign ports have thought of these ships with their fine lines, perfect hull, and splendid decoration? They are the modern-day equivalent to a super yacht; they would surely have inspired awe and attention – that may have assisted the Minoan merchants to advertise their arrival and wares.
Palace Workshops
It is interesting that Icarus was accredited with inventing the sail and that Aero linen was used on the ‘first’ aircraft to provide a skin using a similar method to seal flight surfaces over a light structural skeleton frame. Perhaps there is substance to the fabled flight of Daedalus and Icarus. The feasibility of such will be explored in a future article.
Minoan hulls were seaworthy, fast, maneuverable, and repairable: a distinct maritime advantage that other societies were unable to reproduce.
Author’s notes: The fresco may suggest the crew paddled (the crew face forward), rather than rowed (with the crew backward), OR another interpretation is that oars were set down within the hull itself and a counterbalance pulley system was employed to assist the oar count. That would suggest larger ships.
The destination is the navel of the Cyclades: Delos; to celebrate Apollo and pay the Marines (Carians) for military service rendered to support the inter-island and wider mainland mercantile trade activity.
The title illustration suggests the crew were: nude, which is unlikely. It would be hugely difficult to lift the oar as illustrated. It is likely that the passengers (who would have been specialists) would have been protected from above and front (which does not come through in the original art – side view or by modern day interpretation).
Minoan shield technology: a wooden frame; wicker subframe (to absorb kinetic energy) and many skins of leather (stapled and likely glued by a shipwright).
It may have been an act of Minoan maritime law to intercept plain brown (wooden) hulls crossing their territorial seas.
Top Image: Detail of Minoan painting, from Akrotiri, the Ship Procession. Source: Public Domain
By Nik Aed
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