Make a breast strap at least 8 cm wide, ideally 10-12 cm, lined with sheepskin, felt or folded cloth, and set it across the point of the shoulder, not on the windpipe: too high chokes the horse and too low interferes with leg motion. Traces attach at each end and run back to the load.
Part of Harness & Yoke Making
The design of the chest strap in a breast harness: width, padding, position and attachment points.
Width Is The Only Way A Strap Spreads Its Load
A strap pulls on a band of skin. The wider the band, the lower the pressure for the same pull. That is why the source sets a minimum width and why narrow straps concentrate pressure.
What You Need
- Strap material at least 8 cm wide — leather, or a salvaged wide strap. See Leather Alternatives.
- Padding — sheepskin, felt or folded cloth.
- Rings or loops at each end — for the traces.
- The animal, for measuring.
Method: Make And Place The Strap
Step 1: Choose the width. At least 8 cm, ideally 10-12 cm.
Step 2: Pad the inner face. Line it with sheepskin, felt or folded cloth, smooth and without ridges.
Step 3: Place it. Across the point of the shoulder. Too high chokes the horse; too low interferes with the leg motion.
Step 4: Attach the traces. At each end of the strap, running back to the load.
Step 5: Check at work. Watch the animal’s breathing; check the chest afterwards for rubbed hair, heat or swelling.
Worked Example
For the same pull, pressure on the skin is force divided by contact area. If the contact length across the chest is the same for both straps (an assumption), the area is proportional to width.
- Pressure ratio, 12 cm strap to 8 cm strap: 8 / 12 = 0.67.
- So widening from the 8 cm minimum to 12 cm cuts the pressure to about two thirds, a reduction of about one third.
- Going from 10 cm to 12 cm: 10 / 12 = 0.83, a reduction of 17%.
The ratio holds for equal padding and equal contact length. A salvaged strap may be narrower than 8 cm: measure it before using it, and add a wider padded piece underneath if it is.
Common Mistakes
- A narrow strap on a heavy pull — pressure concentrates on a small band.
- No padding — raw webbing or leather rubs.
- Strap sits on the windpipe — the animal coughs and struggles.
- A lumpy fold in the padding — re-lay it flat.
Safety
Windpipe pressure
A strap too high compresses the trachea. Stop work at coughing, noisy breathing or a horse that throws its head. Fit the strap with the horse standing with its head in a natural position, and recheck when it lowers its head to pull.
What’s Next
- Learn next: Surcingle & Belly Band — keeping shafts at the right height
- Combine with: Padding & Cushioning — materials for the lining