Kronan (ship) - Design

Design

Kronan was one of the most heavily armed warships of its time, a three-decker with 105 guns. She had three gundecks with guns from bow to stern. Altogether there were seven separate levels divided by six decks. Furthest down in the ship, above the keel, was the hold and immediately above it, but still below the waterline, lay the orlop; both were used primarily for storage. Above the orlop were the three gundecks, two of which were covered while about half of topmost gundeck was open to the elements in the middle, or waist, of the ship. The bow had one deck, making up the forecastle, and the stern had two decks, including a poop deck.

During the first half of the 17th century, Swedish warships were built according to the Dutch manner, with a flat, rectangular bottom with a small draft. This was a shipbuilding style adapted for the shallow coastal waters of the Netherlands, and allowed for quick construction and tended towards smaller ships. The drawbacks was that the vessels had relatively light, less sturdy structures that were somewhat unstable in rough seas, aspects generally unsuitable for warships. When Kronan was built, the English manner of building had prevailed, giving hulls a more rounded bottom and greater draft, as well as a sturdier frame and increased stability. The underwater part of the stern was also more streamlined below the waterline, which lessened resistance.

Kronan displacement, the ship's weight calculated by how much water it displaced while floating, is not known precisely since there are not exact records of the dimensions. By using contemporary documents describing its approximate measurements, it has been estimated to around 2,300 tonnes. In relation to the number, and sheer weight, of guns, Kronan was heavily over-gunned. It wasn't until after 1650 that European shipwrights had begun building three-deckers on a large scale, and the designs were by the 1660s still quite experimental. Both English and French three-deckers were known to be unstable since they were built high, narrow and crammed with too many guns. The distance between the lowest gunports and the waterline was also quite small. In rough seas these ships were often forced to close the lowest row of gunports, and were thereby deprived the use of their heaviest guns, their most effective weapons. In the 18th century, ships with the same amount and weight of guns as Kronan were built much heavier, usually from 3,000 up to 5,000 tonnes, which made them much more stable. When Kronan was built she was ranked as the third or fourth largest ship in the world, but as the trend moved towards ever greater ships, she was surpassed by several other large warships. At the time she sank, she was down to seventh place, a position shared with many other ships.