Brief description

A cart is a two-wheeled vehicle designed for transport, typically pulled by a person or a draft animal. It is a fundamental advancement in logistics, allowing for the movement of loads far heavier than what can be carried.

Use / Function

• Transport of Goods: Moving crops, wood, stones, or trade goods.
• Transport of People: Basic transportation for travel.
• Warfare: Early chariots were essentially specialized carts.

Operating principle

The cart utilizes the wheel and axle to reduce friction.

• Load Distribution: The load is balanced over the axle, meaning the draft animal (or person) only needs to overcome rolling resistance and inertia, rather than supporting the full weight.
• Rolling vs. Sliding: Wheels roll over the ground, drastically reducing friction compared to a sled.

How to create it

1. Frame Construction: Build a rectangular frame from sturdy wood planks.
2. Axle Mounting: Securely attach the axle (see Axle) to the underside of the frame.
3. Wheel Attachment: Mount the wheels (see Wheel) onto the axle.
4. Shafts/Tongue: Attach two long shafts (for a single animal) or a central tongue (for pairs) to the front of the frame.
5. Harnessing: Use leather or rope to connect the shafts to the animal.

Materials needed

• Wood: Planks for the body, beams for the frame and shafts.
• Axle: A strong wooden or metal axle.
• Wheels: Two sturdy wheels.
• Fasteners: Nails, pegs, or rope to hold the structure together.

Variants and improvements

• Handcart: Smaller, pushed or pulled by a human.
• Wagon: A four-wheeled vehicle (requires a steering mechanism for the front axle).
• Chariot: Lightweight, fast cart for war or racing.
• Tumbrel: A cart that can tilt to dump its load.

Limits and risks

• Terrain: Difficult to use on very rough, muddy, or steep terrain.
• Balance: If the load is not balanced over the axle, it puts excessive strain on the animal (lifting them up or pushing them down).
• Maintenance: Axles need regular greasing; wheels can break.