The schematic MTDC gravel bag pattern on page 9 shows the general layout. Plan dimensions could vary slightly based on fabric used. Fabricate a prototype before mass producing. The steel hoop should be fabricated first.
STEEL HOOP DETAIL
1. Steel bar is 1-1/4" x 45-1/2" x 3/16".
2. From the center point of the bar,
measure 6" out on each side and make
90° bends on both. Now round the free
ends together and weld.
3. Weld the chain links to the hoop.
A carabiner or metal double snap clip
can be used to connect the chains to
each other. Decker saddles require 9"
of chain on each side, while sawbuck
saddles require 20" per side.
R = right side of material, and W = wrong side
1. Fold material with wrong sides
together, and match 1" side dots with
the back side 2" dots and stitch (Figure A).
2. Check to make sure the material will
fit snugly around the metal hoop, then
3. False Fell Seam: Fold the 2" side
around the 1" side (Figure B). Tuck by
folding it again and stitching as shown.
The second stitch line must be started
from one end to the halfway point. Clip
thread and finish stitch line from the
4. The hoop end will be double-folded.
To reduce bulk, cut 4-1/2" of false fell
seam from the hoop end (Figure C).
5. At the hoop end, fold at the 5-1/2"
6. Stitch completely around on the
4-1/2"stitch line (Figure D).
7. Cut rectangular holes for hoop chain
links. Use a hot-knife if material is
Cordura™, and burn through both layers
8. Insert the hoop and pull the chain
links up through the holes.
9. Fold fabric around the hoop. Hoop
edge should be on the 8-1/2" fold
10. To attach the hoop inside the bag,
stitch close to the fold edge on the
inside of the hoop (Figure F).
11. To secure the hoop, stitch over the
stitch line created in Step 6, reinforcing it
since the machine will not sew completely
into the corners.Lock stitches (Figure G).
12. Bottom D-ring: Webbing 1-1/2" x 10".
Use 3-point, running 'W' stitch (Figure H).
13. Bottom support: Material 17-1/2" x
with 1" seam tape on all four sides.
14. Attach taped piece on three sides
(two long sides and one short side).
15. Insert 1" x 16" steel or aluminum
strip. Sew open end shut.
This page last modified October 1, 1999