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 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 regulati ...

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 C ...

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 Square rig is a generic type of sail and rigging arrangement in which the primary driving sails are carried on horizontal spars which are perpendicular, or square, to the keel of the vessel and to the masts. These spars are called ''yards'' and ...

ships. To climb above the lower mast to the

topmast The masts of traditional sailing ships were not single spars, but were constructed of separate sections or masts, each with its own rigging. The topmast is one of these. The topmast is semi-permanently attached to the upper front of the lower ...

and above, sailors must get around the

top A spinning top, or simply a top, is a toy with a squat body and a sharp point at the bottom, designed to be spun on its vertical axis, balancing on the tip due to the gyroscopic effect. Once set in motion, a top will usually wobble for a few ...

, a platform projecting from the mast. Although on many ships the only way round was the overhanging

futtock shrouds {{for, 1970 British television comedy, Futtocks End Futtock shrouds are rope, wire or chain links in the rigging of a traditional square rigged ship. They run from the outer edges of a top downwards and inwards to a point on the mast or lower ...

, modern-day tall ships 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 to ...

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 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 are u ...

s is minimal due to obvious safety issues. Today, Jacob's ladders are used only to board

lifeboats Lifeboat may refer to: Rescue vessels * Lifeboat (shipboard), a small craft aboard a ship to allow for emergency escape * Lifeboat (rescue), a boat designed for sea rescues * Airborne lifeboat, an air-dropped boat used to save downed airmen A ...

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 m ...

s and as a draft ladder.

References

Sailing ship components Vertical transport devices Watercraft components {{Water-transport-stub