Halfpipe Construction: The Shape of Things to Come
by Greg Johnson

In the eyes of snowboarders, one of the most difficult structures to build and maintain is a quality halfpipe. From the humble beginnings of snowboarding (please read; A Complete History of the Snowboard Halfpipe by Lee Crane), halfpipe rulers have been doing battle with contest organizers, mountain operations, and mother nature to assure that they at least have a meager place to practice their craft. Stories are legion, even at the World Cup level, of pipes almost unrideable, producing a contest which looks lame at best, and dangerous at worst.

In the past, a significant amount of halfpipe anxiety was due to the learning curve of a new sport, and educating resorts and pipe construction personnel on how to prepare the best shapes with basic resort equipment. This mode of operation is changing with the advent of new snowboard specific technology both in machine and hand tools. As technology has made halfpipes better, the standards have also been. Most halfpipe riders have a vision of what an ideal pipe should look like, but shifting that vision into reality seems to be a quantum leap.

The problem lies in the fact that too many people who control the decision making process view the halfpipe as a fixed and static feature, and that once built, a pipe is left to the forces of nature. A severe change of opinion is needed, as the halfpipe needs to be thought of as an elastic form (almost lifelike) that changes daily and which needs continual maintenance. Another huge factor in developing consistent halfpipes is a set of standards. Over the years the NASBA, OP, USASA, USSA, ISF, and FIS have given differing pipe dimensions to resorts. All this help from various organizations has left pipe building more of an art than a science. Both the ISF and the FIS are now promoting similar versions of halfpipe dimensions. We hope this will assist the construction process greatly.

Halfpipe Technical Information
The standards now being proposed by the ISF and FIS are as follows:

Technical Data Inclination Length Width Wall Height Transition Vertical* Bottom Flat* Drop in Area* Banner fence from wall* Outside fence from banners*

Minimum 15 degrees 100m 13m 3m 4m

Recommended 18 degrees 110m 15m 3.5m 4m 0.3m @ 85 degrees 5m maximum 2m 1.5m 0.5m

Maximum 20 degrees 20m 17m 4m 6m

*These measurements are given as only one value due to the fact that these numbers should be consistent at every halfpipe contest.

The Foundation
There are four factors which will affect the outcome of any halfpipe. These include: Site, Snow, Orientation and the Work/Expense involved. All must be in harmony. Out of these four the most important is the site and the mechanics that surround selecting the best location.

1. The Site
2. Snow
3. Orientation of the Pipe
4. Work/Expense of Halfpipe Construction

The Construction
Construction should begin at the top and move to the bottom following the fall-line using gravity to the advantage of the snowcats. Remember to give yourself about a week to complete the project as all the halfpipe elements take longer than expected. Listed below are the steps for constructing a halfpipe.

1. Read the recommended pipe dimensions, and use it.
2. Pick the proper site.
3. Make enough snow to have a huge pile (roughly 4000 cubic meters).
4. Find an expert snowcat driver with experience shaping pipes.
5. Smooth the initial pile of snow to work with and block out initial shape.
6. Stake out the width of the walls for the orientation of the pipe.
7. Remove material from the channel of the halfpipe with the snowcat.
8. Measure wall to wall distance and verify all dimensions.
9. Shape the roll out decks with the snowcat.
10. Shape the transition with a Pipe Dragon, other device, or by hand.
11. Shape the vertical by hand.
12. Remove excess material from the bottom of the halfpipe with the snow cat.
13. Shape the start area.
14. Buff out the roll-out decks.
15. Place fencing if necessary.
16. Maintain the halfpipe as needed.

When building a halfpipe pay close attention to the initial shaping of the snowcat. Do not remove too much material from the walls on the beginning pass and try to cut down the channel in a V type formation with the snowcat. This will leave enough snow for the Pipe Dragon, back hoe or humans to shape in a smooth transition to the bottom of the halfpipe. If you remove too much material from the walls you will have too much flat bottom, the walls will be to vertical and the maintenance of the walls will be difficult because the pipe will get wider and wider as the sun melts it out.

When shaping the vertical by hand remember to use stakes and string to keep the line straight along the walls of the halfpipe. All shaping starts at the top and shapes down from the vertical. After this is complete along both walls the shapers go inside the pipe and pull down the loose material to the bottom. The best tools for shaping a halfpipe are the Heine tools which are a very specific vertical shaping shovel and a oversize rake that pulls down material very effectively.

When dealing with difficult conditions i.e.; too icy or too soft, remember the following: if the conditions are icy wait until the afternoon when the pipe is at its warmest to start shaping and working the pipe. Using special tools like chain saws, back hoes and other heavy implements might be your only chance in altering pipe shape. If the pipe is too mushy salt must be used in conjunction with patching the divots and chunks that get pulled from the wall. Using some light plywood and compressing snow behind and packing under pressure sometimes works in fixing holes in the halfpipe walls.

Things to avoid in Halfpipe Construction
1. Bad site selection and lack of halfpipe specifications.
2. Not enough snow in the formative pile.
3. No experienced snowcat drivers to push snow.
4. Halfpipe initial channel is flawed.
5. Walls are uneven.
6. The flat bottom to large.
7. The transition to small. (This is the worst)
8. Too much vertical.
9. Too little vertical.
10. Halfpipe wall are over vertical.

Maintenance
What makes or breaks a halfpipe in the course of a season is how well it is maintained. It is essential to take care of the investment. The destroyers of a halfpipe are the sun, fresh snow, and neglect. It is important to remove fresh snow the day it happens and remove the excess of material from the bottom of the pipe.

In spring conditions or when warm the pipe might need 1-3 snowcat hours every other day, along with significant man hours to keep the pipe in shape. It is better to maintain the pipe on a daily basis rather than risk trying to salvage the halfpipe if things go bad.

During a competition the halfpipe will need to be maintained after training runs and at the end of the competition day. Everything should be rechecked as far as specifications and a staff should be available to assist in reshaping the pipe.

Materials for Halfpipe Construction
Snowcats: Good snowcats that have experienced drivers and have the ability and power to push big quantities of snow, a large blade to push snow and a tiller buff out the bottom of the pipe.

Pipe Dragon, back hoe or lots of humans: One of these devices are essential in forming the transition of the halfpipe. Since this is the most important part of the pipe that usually gets screwed up the most it is imperative that someone really knows what they are doing.

Shovels and rakes: Kurt Heine has made the best implements for halfpipe shaping and maintenance. These shovels and rakes are specific to halfpipe building and are constructed beefy to withstand abuse. The shovels are heavy, flat bladed and have extra long reach. the rakes are oversized, well spaced teeth and also have long handles. Buy them if you can find them as Kurt is no longer making these great tools.

Other helpful materials:
1. 10 Stakes
2. Lots of String
3. Spray Paint
4. Inclinometer
5. Measuring Tape
6. Chain saw
7. Salt
8. Whiskey

These items will help in outlining the specifications of the halfpipe and keep you on track when shaping the beast. Use the stakes and string and paint to mark the top of the walls or edges when needed. The inclinometer is used to make sure of the slope of the halfpipe channel. The salt is used when the pipe is mushy from the sun. And the whiskey....well the whiskey is used when the whole thing starts to fall apart, or to tempt the snowcat driver into making one more pass at buffing out the roll-out decks. You get the picture.

The Big Picture
The halfpipe is part of snowboarding's unique culture. Unlike skating which has a complete, fixed and solid halfpipe, the snowboarder has to contend with inconsistent pipes and the forces of nature. The perfect halfpipe has yet to be built for snowboarders, but the time is close when all riders can have the same consistency in pipe shape and design from site to site. As the sport develops and better tools allow the building of halfpipes to become more consistent, the range of tricks and the ability of riders will continue to grow and halfpipe riding will attract more dedicated riders who enjoy the sensation of floating and catching big air. We as riders have just scratched the surface of what will be done in the halfpipe, it is up to all of us to push the limits to see what we can build and accomplish in the halfpipe.