Materials List
The following is a complete listing of materials required to build
this ski ramp.
4" CHANNEL - 5.4 lb/ft 158'2"
2" X 3" X 0.188 HSS 70' 4 1/2"
1" X 2" X 0.100 HSS 179'
2" X 2" X 1/4" ANGLE 168'
2" X 2" X 3/16" ANGLE 174'
1" X 1/4" FLAT 177'
2" X 1/4" FLAT 20'
3" X 1/4" FLAT 2' 2"
3/4" PIPE 8"
1 1/2" PIPE 10'
2" PIPE 8' 10"
2 1/2" PIPE 2' 6"
5/16" ROD 42'
12' CHAIN
14' COPPER PIPE
2 HEAVY DUTY PULLEY BLOCKS
2 PULLEYS
2 WINCHES
2 HYDRAULIC JACKS, 1 1/2 TON, 13" MINIMUM TRAVEL
18 7" x 20" x 8' DOW DOCK BILLETS
36 HEAVY DUTY JOIST HANGERS
24 2" X 10" FIR JOISTS
8 1/2" X 4' X 8' SHEETS GIS PLYWOOD
14 3/4" x 4' x 8' SHEETS GIS PLYWOOD
AXLE AND WHEEL ASSEMBLY
PAINT AND SEALER
500 #10-24 X 1 1/2" WAFER HEAD TEK SCREWS
(use to attach wing plywood to angle iron)
750 #12 X 2" STAINLESS STEEL SCREWS FLAT HEAD, ROBERTSON
(use to attach deck plywood, 6" spacing)
600 #8 X 1 1/2" STAINLESS STEEL SCREWS
(use to attach joists and joist hangers to joist end plates)
2 - 1/4" X 2" BOLTS/NUTS - secure top of jacks
2 - 1/4" X 3 1/2" BOLTS/NUTS
(secure main hinge sleves to main hinge pins)
24 - 1/4" X 2 1/2" S.S. BOLTS/NUTS
(secure joist end plates to deck trusses)
16 - 3/8" X 1" BOLTS/NUTS
(secure winches, jacking beam, safety chains and pulley blocks)
9 - 3/8" X 1 1/2" BOLTS/NUTS
(set screws for cable sleeves & boat bumpers, shafts for pulleys)
12 - 1/2" X 1" BOLTS/NUTS - to attach wings to wing hangers
3 - 1/2" X 5" BOLT/NUT - to attach towing bar to coupler
6 - 1/2" X 2 1/2" BOLTS/NUTS - to attach jack bases and wing braces
THE FOLLOWING IS A LISTING OF PIECES REQUIRED TO FABRICATE
EACH COMPONENT OF THE JUMP
TRAILER FRAME
4' CHANNEL 2 @ 8" BRACKET FOR PULLEY BLOCK
4 @ 11' 4" FRONT/REAR TRUSSES
4 @ 26' MAIN TRAILER TRUSSES
2" X 3" HSS 5 @ 11' 4" FLOATATION SUPPORT
1" X 2" HSS 6 @ 26' FLOATATION SUPPORT
4 @ 2' WINCH MOUNTS
1/4" X 1" FLAT 108 @ 12" TRUSSES
2" X 2" x 1/4" ANG 2 @ 11" FRAME FOR TOWING BAR
2 @ 14" FRAME FOR TOWING BAR
1 @ 8 1/2" FRAME FOR TOWING BAR
1/4" X 2" FLAT 8 @ 3" BRACKETS FOR JACKS AND WING BRACES
1/4" X 3" FLAT 4 @ 4" BASE PLATES FOR WINCHES
2 1/2" PIPE 2 @ 2' MAIN HINGE SLEEVES
2" PIPE 2 @ 2' 2" MAIN HINGE PINS
5 @ 10" SLEEVES
DECK FRAME
2" X 2" x 1/4" ANG 4 @ 25' 8" TRUSSES
2 @ 14' TRUSSES
2 @ 13" 8 1/2" TRUSSES
1/4" X 1" FLAT 10 @ 6" WING HANGERS
54 @ 12" TRUSSES
20 @ 9" WING HANGERS
5/16" ROD 3 @ 14' TIE RODS
3/4" PIPE 6 @ 1" SLEEVES FOR WATERING SYSTEM
2 1/2" PIPE 2 @ 3" MAIN HINGE SLEEVES
TOWING BAR
4' CHANNEL 2 @ 7' 6"
1/4" X 2" FLAT 1 @ 6' 0"
1/4" X 2" FLAT 1 @ 5"
CABLE SLEEVES AND BOAT BUMPERS
1 1/2" PIPE 5 @ 2'
1/4" X 2" FLAT 4 @ 3"
WING
2" X 2" X 3/16" ANG 2 @ 26'
2 @ 19' 8 3/8" APPROX
2 @ 4'
2 @ 7' 8"
2 @ 8' 11 1/3" APPROX
2 @ 6' 2 1/2" APPROX
2 @ 4' 5 1/3" APPROX
2 @ 2' 8 " APPROX
N.B. THE PIECES LISTED AS APPROX. LENGTHS SHOULD BE CUT ON
THE CORRECT ANGLE TO ENSURE A GOOD FIT FOR WELDING.
WING BRACE
1" X 2" HSS 2 @ 7'
JACKING BEAM
2" X 3" HSS 1 @ 13' 8 1/2"
1/4" X 2" 2 @ 5"
3/4" PIPE 1 @ 1"
JACK BASE
1" X 2" HSS 2 @ 6"
1/4" X 2" 2 @ 5"
GENERAL NOTES:
1. Mount the trailer frame so the bottom side is a minimum of 20"
off the ground at the axles. This will prevent the rear of the
jump from dragging on the ground. Although it is not shown, you
may build a box or small truss nad weld the hangers for the axles
to this. Then bolt this assembly to the trailer frame so you can
adjust the position of the axles along the frame as you wish.
2. Floatation recommended are DOW Dock Billets - 7" X 20" X 8'.
We secure the floatation by simply looping rope underneath each
piece near the ends. Tying them snuggly to the 1" X 2" HSS.
Cut the billets to fill under the trailer, as shown. You may find
it necessary to add weight to the bottom end of the jump to get
the proper length of deck above the water.
3. Bolt the main hinge pins to the 3" sleeves that are welded to the
deck trusses to insure that they will not separate.
4. The four winches allow you to move the jump in any direction
and rotate it easily.
5. Secure the safety chain from each side of the trailer frame
to the jacking beam. Otherwise a very strong wind may flip the
deck over resulting in repair work.
6. We cover the front of the trailer frame with 3/4" plywood to
provide a working and access area. The materials list allows for
this.
7. It is recommended that you have the frame sand blasted and
galvanized or coated with epoxy tar.
8. Use a piece of light rope to attach each jack handle to the
jump. It is not always easy to find them in the bottom of the lake.
9. Cap both ends of the 1/2" copper pipe and cut it in half. Put
a tee and ball valve in the middle so you can shut the water off at
that point and also adjust the height of the spray.
10. Drill holes in the 2" pipe sleeves and weld a 3/8" nut at
that spot so the bolt can be used as a set screw to lock the boat
bumpers and the cable sleeves in place.
11. The jack that we have used is a "Shurlift" model R040-B4,
1.5 ton, minimum height 22 7/16", maximum height - 40 15/32".
12. Note that the jump shown in the photos wqs built prior to
using a jacking beam. We have found that the beam is a worthwhile
addition. Mount the jack base as shown on the plans; not in
the photos.