Reference Article

from Wikipedia, the free encyclopedia

Trebuchet

A trebuchet, also sometimes called a trebucket is a medieval siege engine, a weapon employed either to batter masonry or to throw projectiles over walls.

The invention of the trebuchet derives, no doubt, from the ancient sling.

A variant of it, the staff sling, involved using a short piece of wood to extend the arm and provide greater leverage.

A traction trebuchet functions in the same way as a counterweight trebuchet, except that instead of a hoisted weight, the hurling arm is powered by a crew of men, pulling on ropes attached to the short lever arm.

A counterweight trebuchet is powered by a very heavy counterweight, acting on a lever arm.

The fulcrum of the lever (usually an axle) is supported by a high frame, and the counterweight is suspended from the short arm of the lever.

The sling is attached to the end of the long arm of the lever.

One end of the sling is captive, while the other end is hooked to the long arm in such a way as to release when the arm and sling reach the optimal hurling angles.

The trebuchet is energized by lowering the long arm and raising the weighted short arm, usually with a winch, and is locked into the charged state by a trigger mechanism.

With the long arm lowered near ground level, the sling is loaded with the projectile, and laid out on the ground, with the captive and hooked ends away from the target, and the load and pouch laid on the ground toward the target.

When the trigger is released, the weighted short arm is driven by gravity into an accelerating pendulum motion, causing the lighter, long arm of the lever to revolve around the fulcrum at the opposite arc, which in turn, pulls the sling and its contents into a whipping motion at the end of the long arm.

As the arm continues to swing past the vertical position, the counterweight rises causing the lever motion to begin to slow down, while the sling continues to whip forward around the end of the long arm.

When the sling reaches its launch angle, one end slips from its hook, releasing the projectile toward the target.

Note: This article excerpts material from the Wikipedia article "Trebuchet", which is released under the GNU Free Documentation License.

See the following related content on ScienceDaily:


Related Stories


Share This



Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

from the past week

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

    Technology News



    Save/Print:
    Share:  

    Free Subscriptions


    Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

    Get Social & Mobile


    Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

    Have Feedback?


    Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
    Mobile iPhone Android Web
    Follow Facebook Twitter Google+
    Subscribe RSS Feeds Email Newsletters
    Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins