The term Jacob's ladder, used on a ship, applies to two kinds of rope ladders.
The first 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. The name is commonly used without the apostrophe (Jacobs ladder).
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 in a pilot ladder that distinguishes it from a Jacob's ladder.
Spreaders are long treads that extend well past the vertical ropes to stop the ladder from twisting about its long axis (possible when a ship rolls and the ladder is no longer in contact with the ship's side) with the person possibly becoming trapped between the ship's side and the 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. These and railings would be removed and replaced with Jacob's ladders and ropes while preparing for battle the days before. This was done to prevent them from blocking line of sight or turning into
shrapnel
Shrapnel may refer to:
Military
* Shrapnel shell, explosive artillery munitions, generally for anti-personnel use
* Shrapnel (fragment), a hard loose material
Popular culture
* ''Shrapnel'' (Radical Comics)
* ''Shrapnel'', a game by Adam ...
when hit by enemy shells.
The second applies to a kind of
ladder
A ladder is a vertical or inclined set of rungs or steps 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 ...
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 ship
A tall ship is a large, traditionally- rigged sailing vessel. Popular modern tall ship rigs include topsail schooners, brigantines, brigs and barques. "Tall ship" can also be defined more specifically by an organization, such as for a race or fe ...
s often provide an easier vertical ladder from the
ratlines
Ratlines () are lengths of thin line tied between the shrouds of a sailing ship to form a ladder. Found on all square-rigged ships, whose crews must go aloft to stow the square sails, they also appear on larger fore-and-aft rigged vessels ...
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 ship
A ship is a large watercraft that travels the world's oceans and other sufficiently deep waterways, carrying cargo or passengers, or in support of specialized missions, such as defense, research, and fishing. Ships are generally distinguished ...
s and even as recently as the 1950s, their use today on board modern
merchant ship
A merchant ship, merchant vessel, trading vessel, or merchantman is a watercraft that transports cargo or carries passengers for hire. This is in contrast to pleasure craft, which are used for personal recreation, and naval ships, which ar ...
s is minimal due to obvious safety issues. Today, Jacob's ladders are used only to board
lifeboats and
liferaft
A lifeboat or liferaft is a small, rigid or inflatable boat carried for emergency evacuation in the event of a disaster aboard a ship. Lifeboat drills are required by law on larger commercial ships. Rafts ( liferafts) are also used. In the mi ...
s and as a draft ladder.
References
Sailing ship components
Vertical transport devices
Watercraft components
{{Water-transport-stub