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Old 11-10-2008, 07:31 PM   #25
Icelander
 
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Default Re: Sailing Ships -At least until CCoI (Low-Tech) arrives

Cogs

The vessels known as cogs probably trace their descent to open-decked Frisian coasters and first appeared around the mid-10th century. Many of the features of the early cogs were probably borrowed from Viking vessels, but the clumsy transports eventually outcompeted the sleek Viking ships and became the premier vessel of the North Atlantic and Baltic.

Until relatively recently, there was not enough evidence to reconstruct what historical cogs might have looked like. Around the beginning of the 20th century, people living in the areas were cogs had been extensively used were familiar with the term, but applied it indiscriminately to any merchant vessel of more than a century old design. It is only with archaeological finds such as the Bremen Hanse Cog and a number of later discoveries that a definite picture has formed of the primary transport ship of northern Europe during the medieval period.

Cogs were round-bellied transport ships that could carry a lot of cargo for a relatively small crew. The length-to-breadth-ratio was usually close to three to one. They had a high-boarded hull with a steep stem and straight keel. A solid, continuous deck was installed to protect the cargo from the elements and a ship intended for war might have one or two castles on deck.

Features common to all cogs include a single mast rigged with a yard sail, clinker outer planking at the sides of the hull, straight stem and sternpost (as opposed to the rounded Viking stem) and strong cross-beams, which usually protruded through the ship's sides and served to hold the sides together. The hull was built of overlapping plates of oak fastened together with iron rivets. Caulking was generally tarred moss that was inserted into curved grooves, covered with wooden laths, and secured by metal staples called sintels.

The first cogs still had an old rudder on the starboard side, much like Viking ships, but this was later on was replaced by a stern rudder. As the stern rudder is considered an important development in the history of sailing ships and one of the chief advancements of the cog class, no vessel is presented here with an older fashioned starboard rudder.

Optional Modifiers: While the clinker-built method makes it relatively easy to armour the sides and decking of the vessel simply by adding more timber, the hull is usually weak. As a result, the DR of a cog struck below the waterline (such as by reefs or rams) is halved (if two DR scores are given, use the higher DR before halving) and any HT checks caused by underwater damage receive a -1 penalty. Also, cogs are square-rigged, which makes them very difficult to sail into the wind. Unless a greater penalty is given for the vessel in question, Hnd is -1 to windward and speed is slower than a vessel with a lateen-sail or a full rig.

Cog, Early (60‘)
TL: 3
ST/HP: 192†
Hnd/SR: -3/4
HT: 12c
Move: 0.1/4
EWt: 55t
LWt: 91t
Load: 36t
SM: +6
Occ: 12
DR: 12/8
Range: -
Cost: $44K
Locations: M, O, s
Draft: 6‘

This is an example of the kind of cog that might be seen in the Baltic and the Atlantic around the Low Countries between the years of 1000-1200 AD. It is an inefficient design compared to later cogs and compared to knarrer it is heavy, slow and expensive. But the closed-deck provides added comfort to the crew for long voyages and protects the cargo from wave and weather, which is an important consideration when sailing the Atlantic Ocean.

Optional Modifiers: This vessel has a more primative square-rig configuration than later cogs and consequently Hnd is -2 to windward and speed is negliable compared to a lateen-sail or a full-rigged ship.

Cog, Standard (70‘)
TL: 3
ST/HP: 186†
Hnd/SR: -3/4
HT: 12c
Move: 0.1/3.5
EWt: 50t
LWt: 133t
Load: 66t (+17t ballast)
SM: +7
Occ: 14
DR: 15/10
Range: -
Cost: $40K
Locations: M, O, 2s
Draft: 7‘

This was the primary trade vessel of the 13th and 14th century, with some variation in size. While the earlier models could ill compete with knarrer on other points than comfort, these vessels can transport much heavier loads and hence enjoy efficiency of scale. In the 14th century, this vessel is somewhat outdated compared to the best cogs of the day, but it remained in use among people whose shipwrights were not as accomplished as those of the Hanseatic cities.

Hanse Cog, Small (50‘)
TL: 3
ST/HP: 171†
Hnd/SR: -3/4
HT: 12c
Move: 0.1/4
EWt: 37t
LWt: 64t
Load: 27t
SM: +6
Occ: 10
DR: 14/9
Range: -
Cost: $30K
Locations: M, O, s
Draft: 6‘

Hansa (or the Hanseatic League) was an alliance of trading cities and their guilds that established and maintained trade monopoly along the coast of Northern Europe, from the Baltic to the North Sea and inland. Their power reached its zenith during the 14th and 15th century, but most historians place the beginning of the League around 1158 AD (even though the name Hanseatic League is first mentioned in 1267 AD) and it existed in some form until the end of the 16th century. At its core, the power and riches of the Hansa cities stemmed from the mercantile shipping that they controlled.

This vessel and others of similar size were the standard trade vessels of the Hanseatic League in the 13th century. As cogs went, they were fast and shallow-drafted, but they were still not well-suited for anything but bulk transport. Undoubtedly some were used in warfare, but vessels of this size do not appear to have been purpose-built as warships.

Hanse Cog, Medium (77‘)
TL: 3
ST/HP: 178†
Hnd/SR: -3/4
HT: 12c
Move: 0.1/4
EWt: 44t
LWt: 132t
Load: 88t
SM: +7
Occ: 16
DR: 15/10
Range: -
Cost: $39K
Locations: M, O, s
Draft: 7‘

The continual evolution of the cog led to larger and larger vessels being built. This is an intermediate form of cog, with most of the vessel constructed using traditional clinker-built techniques, but the keel laid with carvel-built method. As a result, it’s light and handy compared to other cogs. It’s one of the most advanced hull shapes found in vessels that still remain recognisable ‘cogs’ and do not fit into the ‘holk’ category.

Many of the wrecks that have been found have been around this size and even during times when larger ships reached twice or three times the tonnage, a vessel such as this was probably the workhorse of the Hansa. It is very cheap for its capability and provides a stable archery platform if pressed into battle.

If sold outside the Hansa cities before the year 1400, it would probably go at a premium of 20%-50%, since the carvel hull represents the bleeding edge of technology. After the beginning of the 15th century, it slowly decreases in price as carvel-built holks become more widespread.

Optional Modifiers: Due to the carvel-built keel of this vessel, it uses its full DR 10 against underwater damage and does not receive a penalty on HT checks versus such attacks or hazards.

Hanse Cog, Large (70‘)
TL: 3
ST/HP: 248†
Hnd/SR: -3/4
HT: 12c
Move: 0.05/3.5
EWt: 120t
LWt: 320t
Load: 200t
SM: +8
Occ: 20
DR: 20/15
Range: -
Cost: $96K
Locations: M, O, 2S
Draft: 9‘

The ability to ship more cargo with a small crew led to an ever-increasing demand for larger cogs. Technical limitations of clinker-built hulls made this an expensive initial investment, but the savings on labour costs and economies of scale made up for it. But there were hard limits on how big one could make a classic cog. That eventually led to the abandonment of the cog as a transport vessel and its replacement with the holk, a carvel-built ship that incorporated many features of the cog into its design.

Optional Modifiers: The tall castles impose a penalty of -1 to Hnd if the vessel is exposed to high winds from the sides.

War Cog (80‘)
TL: 3
ST/HP: 290†
Hnd/SR: -3/4
HT: 13c
Move: 0.05/3
EWt: 190t
LWt: 370t
Load: 180t
SM: +8
Occ: 40+140
DR: 25/15
Range: -
Cost: $152K
Locations: M, O, 2S
Draft: 9‘

A large cog fitted as a warship. It features a thicker hull and a high sterncastle and forecastle that serve as firing platforms for crossbowmen or archers. While this is hardly a fast vessel, it can nevertheless be very hard for lower-decked vessels to board or sink.

Optional Modifiers: The tall castles impose a penalty of -1 to Hnd/SR if the vessel is exposed to high winds from the sides.

Cog Greatship (218‘)
TL: 3
ST/HP: 557†
Hnd/SR: -5/4
HT: 12c
Move: 0.02/2
EWt: 1350t
LWt: 2750t
Load: 1400t
SM: +10
Occ: 200+200
DR: 30/20
Range: -
Cost: $1,296K
Locations: M, O, 2S
Draft: 21‘

When the English warship Grace Dieu was built in 1418, it was the largest vessel in the world. It was certainly by far the largest clinker-built vessel ever attempted. Unfortunately, it never saw action and was quickly beached. It ended its days by burning down to the waterline after being struck by lightning.

Opinions are divided on whether it would have been useful in battle or not. It was certainly large enough to carry an enormous mass of soldiers (if accommodations are not needed, thousands can be packed aboard) and the imposing castles reached over 50’ from the waterline, which suggests that it would have been hard to do any harm to any archers inside them without cannon. On the other hand, the Grace Dieu was likely slow and sluggish, which might have made it irrelevant in battle. If the enemy could manoeuvre around it, the battle might be over before it could make its presence felt.

Optional Modifiers: The tall castles impose a penalty of -1 to Hnd/SR if the vessel is exposed to high winds from the sides.

© 2008 Garđar Steinn Ólafsson
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Last edited by Icelander; 11-20-2008 at 05:14 AM.
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