Covered Bridge Builder Game

HOW A TRUSS WORKS

A truss works to hold up a bridge by transferring the weight that is on top of a bridge up through the vertical posts and down through the 45 degree braces until the force reaches the abutements (the stone or cement ends of the river shore). The force is then absorbed into the earth. If the bridge does not have this triangular design, all the force of the weight becomes concentrated on a particular part of the bridge and the stress may break it.

Click on the Play (arrow below) to see how the force of the weight is transferred to the abutements.

(1) The green arrow shows the weight of the car pushing down on the bottom chord of the bridge.

(2) The vertical post is attached to the bottom chord. The vertical post pulls up on the bottom chord to hold the car's weight. The force of the weight travels up the post (red arrow).

(3) The force of the car's weight then travels down along the 45 degree angle braces and into the next vertical post.

(4) The force continues to travel up each vertical post and down each 45 degree brace until the force reaches the abutements and is dispersed into the ground.

	Covered Bridge Builder Game HOW A TRUSS WORKS A truss works to hold up a bridge by transferring the weight that is on top of a bridge up through the vertical posts and down through the 45 degree braces until the force reaches the abutements (the stone or cement ends of the river shore). The force is then absorbed into the earth. If the bridge does not have this triangular design, all the force of the weight becomes concentrated on a particular part of the bridge and the stress may break it. Click on the Play (arrow below) to see how the force of the weight is transferred to the abutements. (1) The green arrow shows the weight of the car pushing down on the bottom chord of the bridge. (2) The vertical post is attached to the bottom chord. The vertical post pulls up on the bottom chord to hold the car's weight. The force of the weight travels up the post (red arrow). (3) The force of the car's weight then travels down along the 45 degree angle braces and into the next vertical post. (4) The force continues to travel up each vertical post and down each 45 degree brace until the force reaches the abutements and is dispersed into the ground.