A grappling hook or grapnel is a device invented by the Romans in approximately 260BC  The grappling hook was originally used in naval warfare to catch ship rigging so that it could be boarded. They typically have multiple hooks (known as claws or flukes), attached to a rope; it is thrown, dropped, sunk, projected, or fastened directly by hand to where at least one hook may catch and hold. Generally, grappling hooks are used to temporarily secure one end of a rope. They may also be used to dredge for submerged objects.
A common design has a central shaft with a hole ("eye") at the shaft base to attach the rope, and three or four equally spaced hooks at the end, arranged so that at least one is likely to catch on some protuberance of the target. Some modern designs feature folding hooks to resist unwanted attachment. Most grappling hooks are thrown by hand, but some used in rescue work are propelled by compressed air (e.g., the Plumett AL-52), mortar, or a rocket.
Grappling hooks are used by combat engineers to breach tactical obstacles. When used as such, the grappling hook is launched in front of an obstacle and dragged backwards to detonate trip-wire-fused land mines, and can be hooked on wire obstacles and pulled to set off booby traps on the wire. Two tools are available for this purpose; the rifle-launched grapnel, a single-use grappling hook placed on the end of an M4/M16 rifle, or the crossbow launched version. A grapnel can clear up to 99% of the trip-wires in a single pass. During WW2 British and German ships would tow grappling hooks in the hope of snagging or damaging enemy submarines this was a tactic also employed by the Japanese. Grappling hooks were used at the D-Day landings to aid soldiers climbing the cliffs at the Normandy beaches. 
In popular culture
Grappling hooks, grapple guns and their many variants have been a staple in a large number of video games for at least 30 years now. One of the earliest appearances in gaming is in 1987 arcade game Bionic Commando. More recently they are a central feature of the Just Cause video game series.
|Wikimedia Commons has media related to Grappling hooks.|
- "The Roman Navy and the Grappling Hook". Patent Pending. Retrieved 14 September 2019.
- "Naval Warfare". Britannica. Retrieved 14 September 2019.
- "Boarding Hooks". The Pirate King. Retrieved 14 September 2019.
- The Launch Grapnel Hook (LGH), Infantry Magazine 1999 Sep-Dec pages 4-5
- United States Army Launched Grapnel Hook (LGH) NSN 1095-01-412-4150, formerly Muzzle Launched Grapnel Hook Projectile US5448937
- SAA Crossbow Launched Grapnel Hook
- Field Manual 3-34.2 Combined Arms Breaching Operations. 31 August 2000. Para. C-57 and Table C-2
- "A Brief History of Anti-Submarine Warfare". Globe Composite. Retrieved 14 September 2019.
- McDonald, Craig R. (2007). The USS Puffer in World War II: A History of the Submarine and Its Wartime Crew. p. 68. ISBN 9780786432097.
- "D-Day Landings in WWII Normandy". Classroom. Retrieved 14 September 2019.
- "Subsea Cables". Kis-Orca. Retrieved 15 September 2019.
- "30 years ago, Bionic Commando proved video game grappling hooks are awesome". Games.Avclub. Retrieved 15 September 2019.