Editing Longship (section)

==Construction==
The first longships can trace their origin back to between 500 and 300&nbsp;BC, when the Danish [[Hjortspring boat]] was built.<ref name="Asingh2009">{{cite book|author=Pauline Asingh|title=Grauballemanden|url=https://books.google.com/books?id=zZy-4znpeWIC&pg=PA195|access-date=2 July 2013|year=2009|publisher=Gyldendal A/S|isbn=978-87-02-05688-4|pages=195–}}</ref> It was fastened with cord, not nailed, and paddled, not rowed. It had rounded cross sections and although {{convert|65|ft|m|0|abbr=in|order=flip}} long was only {{convert|6|ft|m|0|abbr=in|order=flip}} wide. The rounded sections gave maximum displacement for the lowest wetted surface area, similar to a modern narrow rowing skiff, so were very fast but had little carrying capacity. The shape suggests mainly river use. Unlike later boats, it had a low bow and stern. A distinctive feature is the two-prong cutaway bow section.
[[Image:Hammars (I).JPG|upright|thumb|The [[Stora Hammars stones|Stora Hammars I stone]], Sweden showing armed warriors in a longship]]

The earliest rowed true longship that has been found is the [[Nydam Mose#Nydam boat|Nydam ship]], built in Denmark around 350&nbsp;AD. It also had very rounded underwater sections but had more pronounced flare in the topsides, giving it more stability as well as keeping more water out of the boat at speed or in waves. It had no sail. It was of lapstrake construction fastened with iron nails. The bow and stern had slight elevation. The keel was a flattened plank about twice as thick as a normal strake plank but still not strong enough to withstand the downwards thrust of a mast.

Sails started to be used from possibly the eighth century. The earliest had either plaited or chequered pattern, with narrow strips sewn together.<ref>[[Magnus Magnusson]]. ''The Vikings''. p. 90, History Press. 2008, {{ISBN|978-0752426990}}</ref>

In the late eighth century, the [[Kvalsund ship]] was built.<ref>{{cite journal| last1=Nordeide | first1=S.W. | last2=Bonde | first2=N. | last3=Thun | first3=T. | year=2020 | title=At the threshold of the Viking Age: New dendrochronological dates for the Kvalsund ship and boat bog offerings (Norway) | journal=Journal of Archaeological Science: Reports | volume=29 | page=102192 | doi=10.1016/j.jasrep.2020.102192 | s2cid=214352713 | doi-access=free | hdl=1956/22938 | hdl-access=free }}</ref> It is the first with a true keel. Its cross sectional shape was flatter on the bottom with less flare to the topsides. This shape is far more stable and able to handle rougher seas. It had the high prow of the later longships. After several centuries of evolution, the fully developed longship emerged some time in the middle of the ninth century. Its long, graceful, menacing head figure carved in the stern, such as the Oseburg ship, echoed the designs of its predecessors. The mast was now square in section and located toward the middle of the ship, and could be lowered and raised. The hull's sides were fastened together to allow it to flex with the waves, combining lightness and ease of handling on land. The ships were large enough to carry cargo and passengers on long ocean voyages, but still maintained speed and agility, making the longship a versatile warship and cargo carrier.

===Keel, stems and hull===

[[File:Sebbe Als 2.jpg|thumb|Schematic drawing of a longship construction representing the [[Sebbe Als]] ship. It is a reconstructed ''snekke'' from Denmark.]]
[[File:Immegram kyst.jpg|thumb|The ships' design gave both strength, agility and versatility. They could navigate the open ocean, coastal waters, fjords and many rivers and could be landed on a beach. The pictured ship is the reconstructed ''Imme Gram''.]]
The Viking shipbuilders had no written diagrams or standard written design plan. The shipbuilder pictured the longship before its construction, based on previous builds, and the ship was then built from the keel up. The keel and stems were made first. The shape of the stem was based on segments of circles of varying sizes. The keel was an inverted T shape to accept the garboard planks. In the longships the keel was made up of several sections spliced together and fastened with treenails. The next step was building the strakes—the lines of planks joined endwise from stem to stern. 

Nearly all longships were [[clinker (boat building)|clinker]] (also known as lapstrake) built, meaning that each hull plank overlapped the next. Each plank was hewn from an oak tree so that the finished plank was about {{convert|25|mm|in|abbr=in|sigfig=1}} thick and tapered along each edge to a thickness of about {{convert|20|mm|in|abbr=in|sigfig=1}}. The planks were riven (radially hewn) so that the grain is approximately at right angles to the surface of the plank. This provides maximum strength, an even bend and an even rate of expansion and contraction in water. This is called in modern terms quartersawn timber, and has the least natural shrinkage of any cut section of wood. 

The plank above the turn of the bilge, the ''meginhufr'', was about {{convert|37|mm|in|abbr=in}} thick on very long ships, but narrower to take the strain of the crossbeams. This was also the area subject to collisions. The planks overlapped by about {{convert|25|–|30|mm|in|abbr=on|1}} and were joined by iron rivets. Each overlap was stuffed with wool or animal hair or sometimes hemp soaked in pine tar to ensure water tightness. Amidships, where the planks are straight, the rivets are about {{convert|170|mm|in|abbr=in}} apart, but they were closer together as the planks sweep up to the curved bow and stern. There is considerable twist and bend in the end planks. This was achieved by use of both thinner (by 50%) and narrower planks. In more sophisticated builds, forward planks were cut from natural curved trees called reaction wood. 

Planks were installed unseasoned or wet. Partly worked stems and sterns have been located in bogs. It has been suggested that they were stored there over winter to stop the wood from drying and cracking. The moisture in wet planks allowed the builder to force the planks into a more acute bend, if need be; once dry it would stay in the forced position. At the bow and the stern builders were able to create hollow sections, or compound bends, at the waterline, making the entry point very fine. In less sophisticated ships short and nearly straight planks were used at the bow and stern. Where long timber was not available or the ship was very long, the planks were butt-joined, although overlapping scarf joints fixed with nails were also used.

As the planks reached the desired height, the interior frame (futtocks) and cross beams were added. Frames were placed close together, which is an enduring feature of thin planked ships, still used today on some lightweight wooden racing craft such as those designed by Bruce Farr. Viking boat builders used a spacing of about {{convert|850|mm|in|abbr=in}}. Part of the reason for this spacing was to achieve the correct distance between rowing stations and to create space for the chests used by Norse sailors as thwarts (seats). The bottom futtocks next to the keel were made from natural L-shaped crooks. The upper futtocks were usually not attached to the lower futtocks to allow some hull twist. The parts were held together with iron rivets, hammered in from the outside of the hull and fastened from the inside with a rove (washers). The surplus rivet was then cut off. A ship normally used about {{convert|700|kg|lb|abbr=in}} of iron nails in a {{convert|18|m|ft|abbr=in}} long ship. In some ships the gap between the lower uneven futtock and the lapstrake planks was filled with a spacer block about {{convert|200|mm|in|abbr=in|sigfig=1}} long. In later ships spruce stringers were fastened lengthwise to the futtocks roughly parallel to the keel. Longships had about five rivets for each yard ({{convert|90|cm|in|abbr=in|disp=or}}) of plank. In many early ships treenails (trenails, trunnels) were used to fasten large timbers. First, a hole about {{convert|20|mm|in|abbr=in|sigfig=1}} wide hole was drilled through two adjoining timbers, a wooden pegs inserted which was split and a thin wedge inserted to expand the peg. Some treenails have been found with traces of linseed oil suggesting that treenails were soaked before the pegs were inserted. When dried the oil would act as a semi-waterproof weak filler/glue.

The longship's narrow deep keel provided strength beneath the waterline. A typical size keel of a longer ship was {{convert|100|x|300|mm|in|abbr=in|sigfig=1}} amidships, tapering in width at the bow and stern. Sometimes there was a false outer keel to take the wear while being dragged up a beach. These large timbers were shaped with both adze and broadaxe. At the bow the cut water was especially strong, as [[longboat]]s sailed in ice strewn water in spring. Hulls up to {{convert|5.60|m|ft|abbr=in}} wide gave stability, making the longship less likely to tip when sailed. The greater beam provided more moment of leverage by placing the crew or any other mobile weight on the windward side. Oceangoing longships had higher topsides about {{convert|1|m|ft|abbr=in|0}} high to keep out water. Higher topsides were supported with knees with the long axis fastened to the top of the crossbeams. The hull was waterproofed with animal hair, wool, hemp or moss drenched in pine tar. The ships would be tarred in the autumn and then left in a boathouse over the winter to allow time for the tar to dry. Evidence of small scale domestic tar production dates from between 100&nbsp;AD and 400&nbsp;AD. Larger industrial scale tar pits, estimated to be capable of producing up to {{convert|300|l|USgal|sigfig=1}} of tar in a single firing have been dated to between 680&nbsp;AD and 900&nbsp;AD.<ref>{{Cite news|url=https://www.theguardian.com/science/2018/nov/04/viking-longboat-industrial-tar-pits-dominance-seas|title=The secret of Viking success? A good coat of tar…|last=McKie|first=Robin|date=4 November 2018|work=The Observer|access-date=3 November 2019|language=en-GB|issn=0029-7712|archive-date=2 November 2019|archive-url=https://web.archive.org/web/20191102220502/https://www.theguardian.com/science/2018/nov/04/viking-longboat-industrial-tar-pits-dominance-seas|url-status=live}}</ref> A drain plug hole about {{convert|25|mm|in|abbr=in|sigfig=1}} was drilled in the garboard plank on one side to allow rain water drainage.

The oars did not use rowlocks or thole pins but holes cut below the gunwale line. To keep seawater out, these oar holes were sealed with wooden disks from the inside, when the oars were not in use. The holes were also used for belaying mooring lines and sail sheets. At the bow the forward upper futtock protruded about {{convert|400|mm|in|abbr=in}} above the sheerline and was carved to retain anchor or mooring lines.

===Timber===
Analysis of timber samples from Viking long boats shows that a variety of timbers were used, but there was strong preference for [[Oak#Uses|oak]], a tree associated with [[Thor]] in Viking mythology. Oak is a heavy, durable timber that can be easily worked by adze and axe when green (wet/unseasoned). Generally large and prestigious ships were made from oak. Other timber used were [[Fraxinus|ash]], [[Elm#Wood|elm]], [[pine]], [[spruce]] and [[larch]]. Spruce is light and seems to have been more common in later designs for internal hull battens (stringers). Although it is used for spars in modern times there is as yet no evidence the Vikings used spruce for masts. All timber was used unseasoned. The bark was removed by a [[bark spud|bark spade]]. This consisted of a {{convert|1.2|m|ft|adj=mid|long}} wooden handle with a T crossbar at the upper end, fitted with a broad chisel-like cutting edge of iron. The cutting edge was {{convert|60|mm|in|abbr=in}} wide and {{convert|80|mm|in|abbr=in}} long with a {{convert|120|mm|in|adj=mid|long}} neck where the handle was inserted. It appears that in cold winters wood work stopped and partly completed timber work was buried in mud to prevent it drying out. Timber was worked with iron [[adze]]s and [[axe]]s. Most of the smoothing was done with a [[Broadaxe|side axe]]. Other tools used in woodwork were [[hammer]]s, [[wedge]]s, [[drawknife|drawknives]], [[plane (tool)|planes]] and [[saw]]s. Iron saws were probably very rare. The [[Domesday Book]] in England (1086&nbsp;AD) records only 13 saws. Possibly these were [[pit saw]]s and it is uncertain if they were used in longship construction.

===Sail and mast===
Even though no longship sail has been found, accounts and depictions verify that longships had square sails. Sails measured perhaps {{convert|35|to|40|ft|m|abbr=in|order=flip}} across, and were made of [[wadmal|rough wool cloth]]. Unlike in [[knarr]]s, a longship sail was not stitched.

The sail was held in place by the mast which was up to {{convert|16|m|abbr=in}} tall. Its base was about {{convert|250|x|180|mm|abbr=in|0}}. The mast was supported by a large wooden maststep called a ''kerling'' ("old woman" in Old Norse) that was semicircular in shape. (Trent) The kerling was made of oak, and about {{convert|700|mm|abbr=in}} wide and up to {{convert|6|m|abbr=in}} long in the larger ships. It usually heavily tapered into a joint with the internal [[keelson]], although keelsons were by no means universal. The kerling lay across two strong frames that ran width-wise above the keel in the centre of the boat. The kerling also had a companion: the "mast fish", a wooden timber above the kerling just below deck height that provided extra help in keeping the mast erect. It was a large wooden baulk of timber about {{convert|3|m|abbr=in|sigfig=1}} long with a {{convert|1.4|m|ft|adj=mid|long}} slot, facing aft to accommodate the mast as it was raised. This acted as a mechanism to catch and secure the mast before the stays were secured. It was an early form of mast partner but was aligned fore and aft. In later longships there is no mast fish—the mast partner is an athwartwise beam similar to more modern construction. Most masts were about half the length of the ship so that it did not project beyond the hull when unstepped. When lowered the mast foot was kept in the base of the mast step and the top of the mast secured in a natural wooden crook about {{convert|1.5|-|2.5|m|ft|abbr=in|sigfig=1}} high, on the port side, so that it did not interfere with steering on the starboard side.

There is a suggestion that the rig was sometimes used in a lateen style with the top cross spar dipped at an angle to aid sailing to windward i.e. the spar became the luff. There is little or no evidence to support this theory. No explanation is offered as to how this could be accomplished with a square sail as the lower reefed portion of the sail would be very bulky and would prevent even an approximation of the laminar flow necessary for windward sailing. There is no evidence of any triangular sails in use. Masts were held erect by side stays and possibly fore and aft stays. Each side stay was fitted at its lower end with a {{convert|150|mm|in|adj=mid|long|0}} toggle. There were no chain plates. The lower part of the side stay consisted of ropes looped under the end of a knee of upper futtock which had a hole underneath. The lower part of the stay was about {{convert|500|-|800|mm|ft|abbr=in}} long and attached to a combined flat wooden turnblock and multi V jamb cleat called an angel (maiden, virgin). About four turns of rope went between the angel and the toggle to give the mechanical advantage to tighten the side stays. At each turn the v-shape at the bottom of the angel's "wings" jambed the stay, preventing slippage and movement.

===Rudder===
Early long boats used some form of steering oar but by the tenth century the side rudder (called a steerboard, the source for the etymology for the word [[Port and starboard|starboard]] itself) was well established. It consisted of a length of timber about {{convert|2.4|m|ft|abbr=in}} long. The upper section was rounded to a diameter of about {{convert|150|mm|abbr=in|0}}. The lower blade was about {{convert|1.8|x|0.4|m|ft|abbr=in}}. The steerboard on the [[Gokstad ship]] in the Viking Ship Museum in Oslo, Norway, is about {{convert|8|in|cm|abbr=in|order=flip}} wide, completely flat inboard and with about a {{convert|3|in|cm|abbr=in|order=flip}} maximum width at the center of the foil. The head of the rudder shaft had two square holes about {{convert|200|-|300|mm|abbr=in|0}} apart. When the rudder was in its normal position the tiller was inserted in the upper hole so that the tiller faced athwartwise. The shaft was attached to the gunwale by a U-shaped joint. Near the stern, about halfway down the starboard topsides, was a rounded wooden block about {{convert|150|mm|abbr=in|0}} in diameter and {{convert|100|mm|abbr=in|0}} high, with a central hole for a rope. This corresponded to a hole in the midsection of the rudder blade. From the outside the rope ran through the blade, through the round block and topsides and was fastened inside the hull. The flexibility of the hemp rope allowed the blade to pivot. When beached or in shallow water the tiller was moved to the lower hole, the blade rope was slackened and the rudder head pulled up so the rudder could operate in shallow waters. Modern facsimiles are reported to steer quite well but require a very large amount of physical effort compared to the modern fore and aft tiller.

===Anchors===
Longships for the most part used two different kinds of anchors. The most common was a natural wood yoke formed from a tree branch. The weight was supplied by a stone passing laterally through the U of the yoke. The top of the yoke was closed by either a length of hardwood or a curved iron head, which kept the stone in place. One side of the head stuck out so it could dig into mud or sand. In the Ladby ship burial in Denmark, a unique iron anchor has been found, resembling the modern fisherman's anchor but without the crossbar. The cross bar may have rusted away. This anchor—made of Norwegian iron—has a long iron chain to which the hemp warp was attached. This construction has several advantages when anchored in deep waters or in rough seas.<ref>{{cite web|url=http://www.vikingeskibsmuseet.dk/en/professions/education/method/the-archaeological-sources/ladby/?T=&S=8|title=Ladby|publisher=Viking Ship Museum, Roskilde|access-date=10 January 2016}}{{Dead link|date=April 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>

===Ship builders' toolkit===

At the height of Viking expansion into Dublin and [[Scandinavian York|Jorvik]] in 875–954&nbsp;AD, the longship reached a peak of development – for example, the Gokstad ship built in 890. Archaeological discoveries from this period at [[Coppergate]], in York, show the shipwright had a large range of sophisticated woodwork tools. As well as the heavy adze, broad axe, wooden mallets and wedges, the craftsman had steel tools such as anvils, files, snips, awls, augers, gouges, draw knife, knives, including folding knives, chisels and small {{convert|300|mm|in|abbr=in}} long bow saws with antler handles. Edged tools were kept sharp with sharpening stones from Norway. One of the most sophisticated tools was a {{convert|25|mm|in|abbr=in|0}} diameter twist drill bit, perfect for drilling holes for treenails. Simple mechanical pole wood lathes were used to make cups and bowls.