Olympic Trap

BUILDING A BUNKER

by Lester L. Greevy, Jr.

A few months ago, this column ran a list of the operating public
International Trap Bunkers in the U.S. There were nineteen. Now there
are twenty. The newest is at my home club, the North Mountain
Sportsmen’s Association (www.northmt.com), Muncy Valley, PA, just off of
Rt. 220, North of Hughesville, in the north central part of the state.

Opening our bunker was the result of two years effort, mostly research
and planning. During that time, I had the opportunity to talk to many
people around the country who had or were building or were planning to
build bunkers. We all were facing or had faced and solved the same or
similar problems. Not all of the solutions were the same. For those of
you who might have interest, let me briefly discuss some important
considerations involved in building a bunker.

By way of review, an International or Olympic Trap Pit is generally
constructed of concrete, over 60' long, contains 15 traps and is dug
into the ground with its roof on the same level as the shooting
stations. It is operated by a computer system that selects which
targets to throw and is activated by a voice release system. It is
expensive. The traditional cost estimate starting point is $100,000 per
field.

It doesn’t have to be that expensive. At North Mountain we built a
modular steel bunker on a concrete slab. The cost, not covering
concrete and site preparation was a little over $50,000, which included
all new state of the art equipment. Most of the money came from a grant
by the Pennsylvania Department of Community and Economic Development.
Additional funds came from the NRA Foundation, Inc. Grant Program.

It doesn’t have to cost that much to begin. Double Trap is shot with
only the three center traps of the Bunker. Automatic Trap (wobble trap)
can be used to train and qualify shooters for USA Shooting Junior
Olympics and PTO (preliminary try out) Competitions. That means
shooters can train for both disciplines with a facility consisting of a
12' wide house holding 3 traps, a wobble trap in the center and 2
stationary traps, one on either side. My Youth Development Shotgun Team
trained on that type of field for its first year and until May of 2003.
During that time, we couldn’t dig the unit into the ground so the kids
stood on wooden boxes to approximate the elevations. It was crude, but
effective. Several current top shooters regularly train on three trap
Bunkers.

If you are planning on building a Bunker, the first thing you should do
is get a USA Shooting Official Rule Book. There are available from
USAS, Competitions, One Olympic Plaza, Colorado Springs, CO 80909. The
cost is about $30.00.

The Technical Rules Chapter (GTR) sets forth the standards for Automatic
Trap (wobble trap), Trap (Bunker), and Double Trap and the critical
dimensions for the Trap, Automatic Trap, and Double Trap pit section and
for the Trap range, clay target pit, firing stations and return walk.

Certain of those dimensions are mandatory and some are optional. The
mandatory ones, including distance from firing station to front edge of
pit roof, distance between traps in each group, and distance from pivot
point of trap throwing arm to top and to front edge of pit roof are
absolutely critical to insure uniform target presentations from field to
field around the world.

Concerning other dimensions, such as the interior of trap pit, form can
follow function. Since the advent of automatic self loading carousel
traps, you don’t have three men inside cocking and loading so you can
economize on space.

The second thing you ought to do is talk to National Coach Lloyd
Woodhouse at USA Shooting and to the other Bunker operators to solicit
their advice. It is my experience that as a group they are very
forthcoming and willing to share their experiences, problems and
solutions with interested folks. Maybe you can borrow a plan with
construction details, elevations and electrical schematics.

The third step is to visit other Bunkers. Take a camera a shoot a lot
of pictures from many different angles. Notice how they get access to
the Bunker to load and store targets. How do they aim and repair
machines, do they have water or snow problems and how do they deal with
them; or must they shut down during the winter? Do they have complete
sun and rain protection, is it permanent or removable? Do they overlay a
skeet field? All of these are important questions that may or may not
be apparent. That itself is a good reason for visiting other Bunker
facilities.

The traditional Bunker is 60' long, 8' wide, and 8' deep made of
concrete and becomes a rather permanent fixture. In this age of
shooting range closings, how sure are you that you will be able to
continue to shoot at that location over the working life of the Bunker
or even over the time needed to depreciate or amortize the cost of
Bunker construction. This is a problem I faced and is the primary
reason I chose to build a modular Bunker made of structural steel. Cost
is another reason.

Five of us constructed our Bunker on its concrete slab in one day.
Another half day was needed to level, plumb and square the Bunker and
install the 15 traps with temporary solar power. Another day was needed
to install the voice releases, computer and permanent electrical wiring.
If necessary, we could remove that Bunker and reconstruct it somewhere
else in about the same time.

The North Mountain Bunker was designed by Joe Reynolds and built by
Reynolds Iron Works, Inc., in Williamsport, Pennsylvania. Joe is a
sporting clay shooter but has never seen a Bunker in the flesh. He did
have many pictures to view and knew the critical dimensions. He also
had plans for a concrete Bunker. We requested that he strictly heed the
critical dimensions, but otherwise to design for convenience, economy,
safety, and efficient use. His end product is a masterpiece of clean
design and quality of construction.

Many experienced International shooters have viewed our Bunker including
Simon Hurley, the Engineer from Promatic, who came over from the UK to
wire up our system and install the computer. If I may brag, their first
reactions have all been exactly the same, “This is the nicest bunker I
have ever been in.” That speaks well for Joe’s Design and RIWI’s work.

Another important decision is trap selection. There are only a few
manufacturers selling Olympic or Bunker Traps, but there are several
variables. One critical issue is power source. Some traps run on
single phase 110v AC; some on 12v DC, easily transformed from 110v AC or
provided by deep cycle battery and solar power. Some systems need three
phase 230/400v. Each has its advantages and disadvantages but it is
important to understand what your options are. We chose the new
Promatic Olympic Traps and are very satisfied with them.

Because by rule, the height of the roof above the pivot of the trap
throwing arm is restricted to one half meter (about 20"), the trap must
have a Bunker or short clay target carousel in order to ease loading and
the carousel must be made for the larger (110mm) International Target,
which will not fit in most carousels sized for American sized (108mm)
targets.

Because there are nine trap setting schemes used in Bunker, the machines
must be easy to adjust and aim and because the 3 Double Trap schemes
require precise setting, the traps must be able to be set precisely and
to hold that setting.

We selected the Electronica Progretti computer system to run our Bunker.
This is the same system used at the Olympic Training Center Range in
Colorado Springs. It is very flexible and allows you to instantly
change among the three Double Trap schemes, to Olympic Trap, to
Universal Trench, to throw practice drills with all rights, lefts, or
center targets, and to test fire all the machines in sequence. There
are many other settings that we haven’t even gotten to yet. The system
is reliable and simple and has the up-to-one-second-delay mandated by
new ISSF Rules for Double Trap. It is easy to learn, pretty much
foolproof, and can be coin or token operated.

Our first big shoot and test of the Bunker was the NRA Advanced Junior
Shotgun Camp held June 23 through 26. We had 17 promising young
American Trap, Skeet and Sporting Clays Shooters, 15 boys and 2 girls.
Our goal was to teach these young shooters the Olympic Shotgun
Disciplines of Trap and Double Trap. USAS Assistant National Coaches,
BJ McDaniels and Jon Olgivie came in to help.

During that camp we threw over 15,000 targets (donated by White Flier)
without a hitch. The system performed perfectly. We had made a lot of
decisions in the planning and construction of our Bunker and its
performance during the camp proved the correctness of those decisions.
That doesn’t mean that our way is the only way or that there are not
other equally successful setups, but our system meets our needs well.

If I can be of any help to you in planning or designing a Bunker, please
do not hesitate to contact me at les@greevy.com.

Next month we will talk more about the NRA Advanced Junior Shotgun Camp
and training young shooters in the Olympic Clay Target Sports.