Clinker (boat building)#Timbering or framing out

File:Clinker diagram 1937 Adm manual seamanship.jpg N:{{nbsp}}{{nautical term|knee}}s O:{{nbsp}}risings P:{{nbsp}}mast thwart S:{{nbsp}}bottom boards T:{{nbsp}}bilge rail V:{{nbsp}}socket for {{nautical term|oar crutch}} (commonly called a rowlock) X:{{nbsp}}{{nautical term|stretcher}} rail (the stretchers fit into notches in this rail)}}]]Clinker construction is a boat and ship-building method in which the hull planks overlap and are joined by nails that are driven through the overlap (often called the "lap"). These fastenings typically go through a metal {{nautical term|rove}} over which the protruding end of the nail is deformed in a process comparable to riveting the planks together. This gives a distinctive appearance to the outside of the hull as the overlaps are obvious in the stepped nature of the hull surface.{{r|Adams 2013|pp=53-54}}{{cite book |last1=Vinner |first1=Max |title=Boats of the viking ship museum |date=2013 |publisher=Viking Ship Museum |location=Roskilde |isbn=978-87-85180-63-6}}{{rp|10-11}}

Clinker construction is a shell-first technique (in contrast to the frame-based nature of carvel). The construction sequence begins with the joining of the {{nautical term|keel}}, {{nautical term|stem}} and {{nautical term|sternpost}} (or {{nautical term|transom}}) and setting these in place in the build area. Thereafter, the shape of the hull is determined by the shaping and fitting of the hull planking that forms the waterproof exterior of the hull. Any reinforcing {{nautical term|frame}}s, {{nautical term|thwart}}s or beams{{efn|In some early instances, beams were notched over the planks, so they had to be installed before the next strake was added. This design was replaced by fastening beam ends to other framing components that spread the load better over the hull surface.}} are added after the joining of the hull planks. This may involve completely finishing the exterior planking first, or just some planking may be fitted with, for instance, {{nautical term|floor}}s being added whilst that part of the hull is accessible before planking is continued.{{r|Adams 2013|pp=53-54}}

File:Clinker built dinghy awaiting restoration.jpg dinghy showing some of the basic structural details. The single rowing thwart supports the aft end of the centre-board case. The pairs of knees at each end of the thwart can be seen; also the longitudinal stringer (rising) on which the thwart rests.]]Medieval clinker construction used iron nails and roves{{snd}}the latter often being a distinctive diamond shape. There are less common regional instances of planks being joined with treenails or by sewing, but iron fastening predominated.{{r|Adams 2013|p=54}} More modern boats generally use copper nails with an annular rove of the same material.{{cite book |last1=Leather |first1=John |title=Clinker Boatbuilding |date=1973 |publisher=Adlard Coles Limited |location=London |isbn=0-229-11504-7}}{{rp|25}}

Historically, particularly in the traditional Nordic tradition{{efn|Nordic clinker construction has been categorised into "traditional" and "modern". These two styles originate from increasing change in the details of clinker construction, starting from the 13th century onwards, but with the traditional remaining in use in the Northern part of Scandinavia, where there was limited urbanisation and little trade to continental Europe. Conversely, the modern tradition adopted ship-building practices that were influenced by contact from outside Scandinavia. Use of sawn planking is an example.{{cite conference |last1=Bill |first1=Jan |date=2006 |section=From Nordic to North European. Analysis in the study of changes in Danish shipbuilding A.D. 900 to 1600 |editor-first=Ronald |editor-last=Bockius |title=Between the Seas. Transfer and Exchange in Nautical Technology. Proceedings of the Eleventh International Symposium on Boat and Ship Archaeology, Mainz 2006 |doi=10.13140/2.1.5120.3204}}}}, clinker construction most commonly used cleft, or radially split, oak planks. This gives a stronger piece of timber than with sawn material{{snd}}not only is the grain continuous along the length of the piece, but the medullary rays are aligned in the same plane as the timber surface, so maximising the strength available. However, this timber conversion method does limit the maximum width of plank to slightly more than one third of the diameter of the tree from which it is split{{snd}}the narrowest part (including any pith) and the sapwood are cut off.{{r|Adams 2013|pp=53-54, 60}}{{Cite book |last1=Gawronski |first1=Jerzy |url=https://books.google.com/books?id=QphLDwAAQBAJ&dq=cleft+plank+on+boat&pg=PA320 |title=Ships And Maritime Landscapes: Proceedings of the Thirteenth International Symposium on Boat and Ship Archaeology, Amsterdam 2012 |last2=Holk |first2=André van |last3=Schokkenbroek |first3=Joost |date=2017-09-25 |publisher=Barkhuis |isbn=978-94-92444-29-5 |pages=320 |language=en}} The slightly uneven surface found on cleft timber is the reason why caulking is laid in the overlap between the hull planks during construction, often using animal hair.{{r|Bill 2006}}

The term clinker derives from a common Germanic word for clinch or clench, a word meaning “to fasten together”.{{cite EB1911|wstitle=Clinker|volume=6|page=527}}

In the first few centuries AD, several boat and ship-building systems existed in Europe. In the Mediterranean, flush-planked hulls were produced by edge-to-edge joining of the hull planking with mortise and tenon joints. This was a shell-first technique{{efn|Other descriptive terms for the same concept include "plank orientated", "planking first", etc,}}, which started with a keel, stem and stern-post, to which planking was added. The hull was then reinforced by the addition of {{nautical term|frame}}s. The shape of the individual planks generates the shape of the hull. In the Roman-occupied parts of Northern Europe, the Romano-Celtic tradition involved flush-planking that was not joined with mortise and tenon joints but was connected by framing elements. (This may be a building tradition that continued with the bottom planking of the medieval cog and then into the Dutch bottom-based building methods of the 17th century.) The Romano-Celtic method of construction is also a shell-first technique, in that the hull shape is dictated by the shaping of the planks, not by the underlying framing of the finished hull.{{cite book |last1=Adams |first1=Jonathan |title=A maritime archaeology of ships: innovation and social change in late medieval and early modern Europe |date=2013 |publisher=Oxbow Books |location=Oxford |isbn=9781782970453}}{{rp|at=ch 4}}

There are precursors of clinker construction. The archaeological remains of a river boat dated to the first two centuries AD (described as Romano-Celtic), found in Pommeroeul in Belgium, had a single {{nautical term|strake}} that overlapped the underlying plank{{snd}}though it is not clear how it was fastened. Earlier finds have bevelled lap joints or other similar arrangements that do not have the full lap of clinker. These include the Dover boat and Ferriby 1 (both dating to the middle of the second millennium BC) and the Hjortspring boat ({{circa|300-350 BC}}). In these cases, the planks are stitched or sewn together. The Hjortspring boat is built shell-first so suggesting some continuity with the Nordic tradition of clinker construction.{{cite book |last1=McGrail |first1=Seán |title=Boats of the world: from the stone age to medieval times |date=2009 |publisher=Oxford University Press |location=Oxford New York |isbn=978-0199271863 |edition=Reprinted}}{{rp|201, 207-210}}{{r|Adams 2013|p=63-66}}

File:Nydam-Boot.JPG

The earliest example of ship and boat building using overlapped planking joined with metal fastenings is in an extended logboat from Björke in Sweden. This dates to {{circa|310 AD}}. The Nydam boat ({{circa|320 AD}}) is an almost complete example of a boat built with clinker construction. It has overlapping planks joined with iron nails driven through the lap. The nails are clenched over {{nautical term|rove}}s on the inside of the planking. The boat was built shell-first.{{r|Adams 2013|p=63-66}}{{r|McGrail 2009|p=210-211}}

Though clinker construction is closely associated with Nordic countries, the same technique was used at an early stage in other parts of Northern Europe. The Saxon burial ship at Sutton Hoo in eastern England is an early ({{circa|630 AD}}) example of this sort of ship occurring in the broader Northern European area. Other sites from the 7th century AD include Kvalsund, Norway, Gretstedbro in Jutland and Snape in eastern England. One difference from the Nydam boat is that individual planks in the later period are shorter and narrower. This suggests that large oak trees for ship-building had become a lot less common by the 7th century, so timber of smaller dimensions had to be used.{{r|Adams 2013|p=65}}{{r|McGrail 2009|p=207-210}}

File:Gokstadskipet1.jpg, a Viking longship, displaying the overlapping planks that characterize clinker construction.]]The 8th, 9th and 10th centuries saw the use of Viking longships for raiding and settlement. Archaeological remains of these clinker-built ships include the Oseberg ship and the Gokstad ship. These show some development from earlier vessels, including a partial {{nautical term|keelson}} which acted as the mast step. As well as these warship types, cargo vessels were built which were less extreme with greater beam and more emphasis on propulsion by sail, together with extra cross-beams to strengthen the hull for greater weight carrying.{{r|McGrail 2009|p=212-217}}

The cog is part of another ship-building tradition in Northern Europe that existed at the same time that the purely Nordic-tradition clinker vessels were being built. Though the classic cog construction uses flush planking for the bottom, the sides are constructed in a clinker method{{snd}}with the difference that the nails that passed through overlapping planks were simply bent over and driven back into the plank, rather than using roves.{{r|Adams 2013|p=66}}

Clinker-built vessels were constructed as far South as the Basque country; the Newport Medieval Ship is an example.{{cite journal |last1=Nayling |first1=Nigel |last2=Jones |first2=Toby |title=The Newport Medieval Ship, Wales, United Kingdom: The Newport Medieval Ship |journal=International Journal of Nautical Archaeology |date=September 2014 |volume=43 |issue=2 |pages=239–278 |doi=10.1111/1095-9270.12053|s2cid=108922370 |url = https://onlinelibrary.wiley.com/doi/10.1111/1095-9270.12053 | access-date = November 17, 2024 | url-access=subscription }}{{cite journal |last1=Nayling |first1=Nigel |last2=Susperregi |first2=Josué |title=Iberian Dendrochronology and the Newport Medieval Ship: Iberian Dendrochronology and the Newport Medieval Ship |journal=International Journal of Nautical Archaeology |date=September 2014 |volume=43 |issue=2 |pages=279–291 |doi=10.1111/1095-9270.12052}} By the 14th century, clinker-built ships and the cog represented the major construction methods in Northern Europe.{{r|Adams 2013|p=66}}

Carvel construction was developed in the Mediterranean around the end of the Classical antiquity period.{{efn|The shipbuilding changes in the Mediterranean region once appeared to be a simple and steady transition away from the mortise and tenon edge-joined hull planking to carvel. As more archaeological finds have been investigated, the evidence suggests that this was not a linear developmental process.}} By the end of the 13th century AD, Mediterranean ships were being built on a skeleton basis, with hull planks being fixed to the frames and not to each other. At the same time, Northern European cogs were voyaging into the Mediterranean. The two maritime technological traditions had differences beyond the hull construction methods. Mediterranean ships were carvel-built, lateen rigged (using more than one mast on larger vessels) and still used side rudders. The visiting cogs had a single square-rigged mast, a stern-post mounted pintle-and-gudgeon rudder and clinker sides. As part of the process of merging these two sets of traditions, carvel-built ships started to arrive in Northern waters. They were soon followed by shipwrights with the skills to build in carvel construction, with the first being built in this region in the late 1430s. The change is still not well understood. The frames of carvel could be made stronger to support the weight of the guns that ships were starting to carry and allowed gun-ports to be cut in the hull. Carvel construction may have solved the shortage of large cleft oak planks from which to make larger clinker vessels.{{r|Adams 2013|p=50, 58-60, 69-72}} Despite the large-scale move over to carvel construction for large vessels, clinker construction remained prominent throughout Northern Europe.

File:Sailors of HMS King Edward VII….jpgGenerally, after the establishment of carvel construction for ships, clinker construction continued for boats across Northern Europe. A wide range of traditional craft were built in clinker. Yawls were ubiquitous around the coasts of Britain and Ireland. They included the fast-sailing Suffolk Beach Yawls; one was recorded making 16 knots.{{cite journal |last1=Cooper |first1=Ernest R. |title=The SUFFOLK and NORFOLK BEACH YAWLS |journal=The Mariner's Mirror |date=1 January 1927 |volume=13 |issue=3 |pages=213–218 |doi=10.1080/00253359.1927.10655424 |url=https://doi.org/10.1080/00253359.1927.10655424 |issn=0025-3359|url-access=subscription }} Examples of more general working craft were the ship's boats that were carried by larger vessels. Some Royal Navy boats that were built in Navy dockyards were carvel-built, but many, including those bought in from builders in Deal were clinker.{{Cite book |last1=May |first1=W E |last2=Stephens |first2=Simon |date=2003 |orig-date=1999 |title=The Boats of Men of War |publisher=Caxton Editions |location=London |isbn=1-84067-4318}}{{rp|28}} The civilian boats built and used in Deal, their crews famous for their servicing of ships anchored in the Downs, were examples of the many beach-launched clinker boats to be found in British waters. At the other end of Britain, Shetland had the yoal and the sixareen. The coasts of Northumberland and Yorkshire had the coble, with its distinctive hull shape.{{cite book |last1=Leather |first1=John |title=Spritsails and Lugsails |date=1979 |publisher=International Marine Publishing Company |location=Camden, Maine |isbn=0877429987 |edition=1989 reissue}}{{rp|115, 118}}{{cite book |last1=Greenhill |first1=Basil |title=Inshore Craft: Traditional Working Vessels of the British Isles |date=2013 |publisher=Seaforth Publishing |location=Havertown |isbn=978-1-84832-167-0}}{{rp|passim}}{{cite book |last1=March |first1=Edgar J. |last2=March |first2=Edgar J. |title=Inshore craft of Britain in the days of sail and oar |date=2005 |volume=1|publisher=Chatham |location=London |isbn=186176264X}}{{rp|31-75, 93-141}}

File:St Ayles Skiff off Anstruther.jpgNordic countries have many traditional boat types that were and are built in clinker. The Nordic clinker boat tradition was inscribed to the UNESCO List of the Intangible Cultural Heritage on December 14, 2021, as the first joint Nordic application to the list.{{cite web | author = Marsio, Leena & FHA Staff | date = 2021-12-14 | title = Nordic Clinker Boat Tradition Inscribed to UNESCO List of the Intangible Cultural Heritage | work = Museovirasto.fi | url = http://www.museovirasto.fi/en/articles/pohjoismainen-limisaumaveneperinne-unescon-luetteloon | access-date = 2024-11-17 | location = Helsinki, Finland | publisher = Museovirasto (Finnish Heritage Agency (FHA)}}

A modern variant of clinker construction is to glue the strakes together rather than using metal fastenings. This is a technique that was pioneered by Iain Oughtred. The planking is normally cut from plywood and, after shaping, is glued with epoxy resin. Based in Britain, Oughtred initially worked on designs based on traditional craft from the United States, but in the mid-1980s he produced designs inspired by Scottish working boats{{snd}}types that were clinker-built. An example of his output is the St. Ayles Skiff and the technique is now used by other boat designers.{{cite news |last1=Compton |first1=Nic |title=Iain Oughtred obituary |url=https://www.theguardian.com/sport/2024/apr/04/iain-oughtred-obituary |access-date=23 March 2025 |work=The Guardian |date=4 April 2024}}{{cite journal |last1=Owner |first1=Practical Boat |title=Eight bells for renowned boat builder and designer Iain Oughtred |journal=Practical Boat Owner |date=27 February 2024 |url=https://www.pbo.co.uk/news/iain-oughtred-tribute-84692 |access-date=23 March 2025}}{{cite web |title=Clinker Ply |url=https://www.selway-fisher.com/clinker_ply.htm |website=www.selway-fisher.com |access-date=23 March 2025}}

{{Gallery|width=195 | height=170 |noborder=yes|perrow=4|

|File:Exhibition in Viking Ship Museum, Oslo 01.jpg|The bow of the Viking Oseberg ship

|File:Kogge stralsund.jpg|Clinker-built medieval cog from Stralsund.

|File:Deal luggers (3).jpg|An 1866 photo of Deal luggers and, in the foreground, a four-oared galley, both types clinker-built

|File:Norwegian pram.jpg|A Norwegian pram dinghy

|File:Bolt in St Mary's Harbour 02.jpg|Cornish pilot gig, a type of working boat from the 19th and early 20th centuries, now popular for racing

|File:Folkeboot Kiel2007.jpg|A Folkboat, a class of clinker-built long-keeled cruiser/racer

|File:Sunnmørsfæring - Herøy kystmuseum.jpg|A Norwegian faering, a four-oared boat

|File:Coble SH105 1 (Nigel Coates).jpg|A coble from the Northeast of England

}}

{{div col|colwidth=15em}}

• Classic Boat (magazine)
• Dragon Harald Fairhair (ship)
• Gableboat
• Montagu whaler
• Longship
• Naglfar
• Oselvar
• Rivet
• Yoal

{{div col end}}

{{notelist}}

{{Reflist}}

• {{cite book | author = Greenhill, Basil | date = 1976 | title = Archaeology of the Boat | location = London, England | publisher = Adam and Charles Black Publishers Ltd. | url = | access-date = | isbn = 9780713616453}}
• {{cite book | author = Greenhill, Basil & Morrison, John S. | date = 1995 | title = The Archaeology of Boats and Ships: An Introduction | location = London, England | publisher = Conway Maritime Press | url = | access-date = | isbn = 9781557500397}}
• {{cite book | author = Leather, John | date = 1990 | title = Clinker Boatbuilding | location = London, England | publisher = Bloomsbury-Adlard Coles | isbn = 9780713636437}}
• {{cite book | author = McKee, Eric | date = 1972 | title = Clenched Lap or Clinker: An Appreciation of a Boatbuilding Technique | location = Greenwich, England | publisher = National Maritime Museum | url = | access-date = | isbn = }}

• UNESCO video[https://www.youtube.com/watch?v=PDF6GhV0OG4] on the Nordic clinker boat tradition

{{Shipbuilding-Footer|state=autocollapse}}

{{Ancient seafaring}}

{{DEFAULTSORT:Clinker (Boat Building)}}

Category:Shipbuilding

Category:Intangible Cultural Heritage of Humanity