Build the cart’s frame from two straight hardwood shaft poles 8-10 cm thick, laid parallel 80-100 cm apart at the bed, with four to six cross-members notched into them in half-lap joints and secured with hardwood pegs or wet rawhide, then lay a plank or pole floor across. Take care over the notches: a half-lap removes half the depth of a rectangular member and leaves a quarter of its bending strength at that section.
Part of Cart & Wagon Construction
The frame and bed of a cart are the pair of shafts and the cross-members and floor between them that carry the load to the axle.
The Notch Is The Weak Point
The carrier builds the bed from the two shaft poles themselves, which run the full length of the cart, with the cross-members let into them. Half-lap joints are quick and strong in the joint but take wood out of the member at the notch.
For a rectangular section, bending strength follows b × h² / 6, where h is the depth. Cutting the depth in half to h / 2 leaves b × (h/2)² / 6 = one quarter of the original. Shaft poles are round rather than rectangular, which behaves a little differently, but the lesson holds: a deep notch in a shaft, in the stretch between the axle and the animal where it bends most, weakens it badly. Notch only as deep as the joint needs, and avoid notching at the axle position and just forward of it.
What You Need
- Two shaft poles: straight hardwood, 2.5-3 m long, 8-10 cm diameter
- Cross-members: four to six pieces, 90-120 cm long, same diameter
- Floor planks or lashed poles
- Pegs, lashing cord, or salvaged bolts
- An axe, saw, chisel, auger and mallet (Woodworking)
- Seasoned timber where possible (Wood Seasoning)
Method: Frame, Joints, Floor
Step 1: Select the shafts Choose two straight poles that run the full length of the cart and extend forward for the animal. Sight along each to check it is straight, and reject any with a large knot or crack in the stretch between the bed and the animal.
Step 2: Lay them parallel Place them 80-100 cm apart at the bed section.
Step 3: Notch the cross-members in Cut half-lap notches in the cross-members and the shafts so they sit flush.
Step 4: Secure Drive hardwood pegs through drilled holes, or lash with wet rawhide, which shrinks tight as it dries (Lashing Techniques).
Step 5: Floor Lay floor planks across the cross-members and peg or lash them down.
Step 6: Converge the front Let the shafts converge slightly so they end about 50-60 cm apart at the hitch point.
Key Dimensions
- Bed length: 120-150 cm
- Bed width: 80-100 cm
- Shaft total length: 250-300 cm
- Ground clearance: 30-40 cm minimum
Common Mistakes
- Deep notches in the shafts — a notch halving the depth leaves a quarter of the bending strength there.
- Pegs in green wood without allowing for shrinkage — the peg loosens as the member dries; use seasoned stock or re-drive.
- Shafts not parallel — the bed twists and the axle sits crooked.
- Floor planks butted tight — rain and mud have no way out, and the floor rots.
Safety
Edge tools and heavy timber
Hewing, notching and chiselling shaft poles put axes and chisels near your hands and legs. Clamp or chock the pole, work with the cut directed away from the body, and do not lift a 3 m pole alone.
What’s Next
- Learn next: Shafts & Hitch Points — the front of the shafts
- Combine with: Wooden Axle Construction — the beam beneath the bed