table saw, and circular saw (small, battery operated, with a 5 1/4" blade is best for cutting the curves) or jigsaw

drill, with phillips head bit, and 1/4" , 3/8" , 1/2" , 3/4" drill bits

carpenter’s square, measuring tape, hammer, pen.

Materials
(based on a 9’ high by 12’ wide by 26’ long modular halfpipe, not pressure treated)
 

plywood..and lots of it..4’ by 8’ sheets....

3/4" "CDX" sheets ("CDX" is cheaper, has knots, but is still strong)

12 sheets

1/2" "BC" sheets ( no knots, cheaper than "AC")

15 sheets

**2 x 4’s..lots of ‘em... 8  feet long... 54 ..GET A FEW EXTRA....

** 12’ long if your’e making this permanent, and not as many..24..and 18  8’ long... ..GET A FEW EXTRA..

2 x 6’s..lots of ‘em ..8 feet and 12 feet long... 42   8 footers and 4   12 footers

(4) 24 foot "longboards" or (8) 16 foot "longboards" (if you have a 16 foot long platform) used to connect the whole thing together...2 by 8’s or 2 by 10's would be best....and while you're at it..get about (20) 1/2" by 5" and (10) 1/2" by 4" threaded bolts with washers and nuts to match..these will bolt the whole thing together

2 x 4 joist hangers (what you say?) you’ll see... 72..MODULAR pipes only

# 14; 2" (that’s number 14, 2 inch long) philips head wood screws.. better buy stock in these ...approx 720 (!) ...ok so why do we need the philips head screw bit ?? :p
 

#12 2" philips head wood screws..don’t even want to count these.., let’s see..hmmm...your screwing the 1/2" plywood (riding surface) to the 2 x 4’s with these...ok..8 per 2 x 4, times 18 2 x 4’s per "section" times 6 sections...844 !.

#12   2  1/2" philips head wood screws..3 boxes

last item....6" by 5/16" stove bolts, 1 washer and nut per bolt; 24 per section, 6 sections,..144 (bolts)  + 144  (washers) + 144  (nuts)

other stuff to aid in the creation:

(2) 1/4" 3 feet long threaded steel rods, with oversized washers and nuts to match..for compressing plywood..you’ll see.....