The term Jacob's ladder, [1] used on a ship, applies to two kinds of rope ladders. [2] The term may also appear without the apostrophe, as Jacobs ladder.
The term Jacob's ladder, [1] used on a ship, applies to two kinds of rope ladders. [2] The term may also appear without the apostrophe, as Jacobs ladder.
The first type of Jacob's ladder is a flexible hanging ladder. It consists of vertical ropes or chains supporting horizontal, historically round and wooden, rungs. Today, flat runged flexible ladders are also called Jacob's ladders. [3]
They are used to allow access over the side of ships, and as a result, pilot ladders are often incorrectly referred to as Jacob's ladders. A pilot ladder has specific regulations on step size, spacing and the use of spreaders. It is the use of spreaders (long treads that extend well past the vertical ropes) in a pilot ladder that distinguishes it from a Jacob's ladder.
When not being used, the ladder is stowed away, usually rolled up, rather than left hanging. On late 19th-century warships, this kind of ladder would replace the normal fixed ladders on deck during battle. Fixes ladders, and railings, would be removed and replaced with Jacob's ladders and ropes in preparation for battle. This was done to prevent such wooden elements from blocking line of sight or turning into shrapnel when hit by enemy shells.
The second type of Jacob's ladder applies to a kind of ladder found on square rigged ships. To climb above the lower mast to the topmast and above, sailors must get around the top, a platform projecting from the mast. Although on many ships the only way round was the overhanging futtock shrouds, modern-day tall ships often provide an easier vertical ladder from the ratlines as well. This is the Jacob's ladder.
While they were a popular way of boarding a vessel or carrying out shipside maintenance during the era of wooden ships, and even as recently as the 1950s, their use today on board modern merchant ships is minimal due to obvious safety issues. Today, Jacob's ladders are used only to board lifeboats and liferafts and as a draft ladder. [4]
The term "Jacob's Ladder" is said to have come from the Bible, Genesis 28:12, when Jacob has a dream of a ladder which reached to heaven. [5]
Seamanship is the art, competence, and knowledge of operating a ship, boat or other craft on water. The Oxford Dictionary states that seamanship is "The skill, techniques, or practice of handling a ship or boat at sea."
A ladder is a vertical or inclined set of rungs or steps commonly used for climbing or descending. There are two types: rigid ladders that are self-supporting or that may be leaned against a vertical surface such as a wall, and rollable ladders, such as those made of rope or aluminium, that may be hung from the top. The vertical members of a rigid ladder are called stringers or rails (US) or stiles (UK). Rigid ladders are usually portable, but some types are permanently fixed to a structure, building, or equipment. They are commonly made of metal, wood, or fiberglass, but they have been known to be made of tough plastic.
A barque, barc, or bark is a type of sailing vessel with three or more masts of which the fore mast, mainmast, and any additional masts are rigged square, and only the aftmost mast is rigged fore and aft. Sometimes, the mizzen is only partly fore-and-aft rigged, bearing a square-rigged sail above.
Scaffolding, also called scaffold or staging, is a temporary structure used to support a work crew and materials to aid in the construction, maintenance and repair of buildings, bridges and all other human-made structures. Scaffolds are widely used on site to get access to heights and areas that would be otherwise hard to get to. Unsafe scaffolding has the potential to result in death or serious injury. Scaffolding is also used in adapted forms for formwork and shoring, grandstand seating, concert stages, access/viewing towers, exhibition stands, ski ramps, half pipes and art projects.
Boat building is the design and construction of boats — and their on-board systems. This includes at minimum the construction of a hull, with any necessary propulsion, mechanical, navigation, safety and other service systems as the craft requires.
A cutter is a name for various types of watercraft. It can apply to the rig of a sailing vessel, to a governmental enforcement agency vessel, to a type of ship's boat which can be used under sail or oars, or, historically, to a type of fast-sailing vessel introduced in the 18th century, some of which were used as small warships.
This glossary of nautical terms is an alphabetical listing of terms and expressions connected with ships, shipping, seamanship and navigation on water. Some remain current, while many date from the 17th to 19th centuries. The word nautical derives from the Latin nauticus, from Greek nautikos, from nautēs: "sailor", from naus: "ship".
A derrick is a lifting device composed at minimum of one guyed mast, as in a gin pole, which may be articulated over a load by adjusting its guys. Most derricks have at least two components, either a guyed mast or self-supporting tower, and a boom hinged at its base to provide articulation, as in a stiffleg derrick. The most basic type of derrick is controlled by three or four lines connected to the top of the mast, which allow it to both move laterally and cant up and down. To lift a load, a separate line runs up and over the mast with a hook on its free end, as with a crane.
A ropes course is a challenging outdoor personal development and team building activity which usually consists of high elements, low elements, or some combination of the two. Low elements take place on the ground or above the ground. High elements are usually constructed in trees or made of utility poles and require a belay for safety.
The top on a traditional square rigged ship is the platform at the upper end of each (lower) mast. This is not the masthead "crow's nest" of the popular imagination – above the mainmast is the main-topmast, main-topgallant-mast and main-royal-mast, so that the top is actually about 1/4 to 1/3 of the way up the mast as a whole.
Each yard on a square or gaff rigged sailing ship is equipped with a footrope for sailors to stand on while setting or stowing the sails.
Crosstrees are the two horizontal spars at the upper ends of the topmasts of sailing ships that are used to anchor the shrouds from the topgallant mast. They may also be mounted at the upper end of the topgallant to anchor the shrouds from the royal mast. Similar transverse spars remain on steamship and motor vessel masts to secure wire antennae or signal flag halyards. In modern sailing vessels, spreaders serve the same purpose.
A pit cave, shaft cave or vertical cave—or often simply called a pit and pothole or pot ; jama in Slavic languages scientific and colloquial vocabulary —is a type of cave which contains one or more significant vertical shafts rather than being predominantly a conventional horizontal cave passage. Pits typically form in limestone as a result of long-term erosion by water. They can be open to the surface or found deep within horizontal caves. Among cavers, a pit is a vertical drop of any depth that cannot be negotiated safely without the use of ropes or ladders.
A chain is a serial assembly of connected pieces, called links, typically made of metal, with an overall character similar to that of a rope in that it is flexible and curved in compression but linear, rigid, and load-bearing in tension. A chain may consist of two or more links. Chains can be classified by their design, which can be dictated by their use:
The automatic tide signalling apparatus or Pilot House at Irvine harbour in North Ayrshire, Scotland, is a category B listed building, and is probably unique, having been invented and patented by Martin Boyd, the Irvine harbourmaster, in 1905 and opened in 1906.
Literally, the word pinisi refers to a type of rigging of Indonesian sailing vessels. A pinisi carries seven to eight sails on two masts, arranged like a gaff-ketch with what is called 'standing gaffs' — i.e., unlike most Western ships using such a rig, the two main sails are not opened by raising the spars they are attached to, but the sails are 'pulled out' like curtains along the gaffs which are fixed at around the centre of the masts.
The sambuca was a ship-borne siege engine which was invented by Heracleides of Tarentum and was first used unsuccessfully by Marcus Claudius Marcellus during the Roman siege of Syracuse in 213 BC.
A pilot ladder is a highly specialized form of rope ladder, typically used on board cargo vessels for the purposes of embarking and disembarking pilots. The design and construction of the ladders is tightly specified by international regulation under the SOLAS regime. Pilot ladders and other boarding arrangements must be carefully prepared for each operation, with the equipment inspected and verified as safe to use before each boarding takes place. Additional requirements relate to the use of man-ropes, platforms, accommodation ladders, combination ladders and securing methods.
Caving equipment is equipment used by cavers and speleologists to aid and protect them while exploring caves. The term may also be used to refer to equipment used to document caves, such as photographic and surveying equipment. Originally, cave diving equipment was quite limited, but the increasing popularity of caving during the 20th century led to the creation of specialist caving equipment and companies.
This glossary of nautical terms is an alphabetical listing of terms and expressions connected with ships, shipping, seamanship and navigation on water. Some remain current, while many date from the 17th to 19th centuries. The word nautical derives from the Latin nauticus, from Greek nautikos, from nautēs: "sailor", from naus: "ship".