Surface Danger Zone and No Blue Sky Concept
By: Clark Vargas
The concept of the Surface Danger Zone (SDZ) comes from WWI when troops were sent in the field for military maneuvers to practice with live fire. One of the maneuver movements that was practiced was coming under attack by strafing aircraft. The practice then was to form the platoon and raise their muzzles up to about 30 degrees and, on command from the platoon leader to volley fire simultaneously, hoping the aircraft would run into the hail of bullets. The resulting 30 degree firing angle is also very close to the optimum angle to achieve maximum range in small arms. Needless to say, troops in the surrounding vicinity up to 3 miles away of the exercise would come under direct fire.
The concept of the SDZ was developed then and used to insure maneuvering troops would be kept out of projectile impact areas of all other units.
When the military developed design manuals for fixed shooting ranges, all open ranges back then, this same concept, the SDZ, was applied to insure no troops would enter the down range SDZ of fixed ranges.
Upon the end of WW II numerous military facilities having shooting ranges were abandoned and the ranges were taken over by civilian shooting clubs and municipalities, presumably these then had proper SDZ.
After WW II another thing happened, suburban development and car ownership exploded creating and allowing encroachment on many shooting ranges endeavors that up to then disturbed no one.
Two encroachment on existing facility societal problems that I am most familiar with are Airports and Shooting Ranges. Others I have been involved in are feed lot slaughter houses and paper mills. These are very expensive facilities to have to move or to site.
Many airports until the late 70’s, early 80’s were routinely closed due to population encroachment creating great expanses for many municipalities. The societal fix was to develop Zoning Regulations that afforded new airport protection “The Airport Compatible Use Zoning (ACUZ)” from encroaching population.
The ACUZ only airport compatible zoning, one the airport is sited. Only appropriate compatible development with in the potential crash and noise zones is allowed around the airport, i.e. commercial, industrial development, no residential.
Ranges like wise in the 90’s were provided “noise” Range Protection from State Legislatures for noise by being provided “grandfather provisions” of different kinds. Feed lots slaughter houses and paper mills have suffered and have been closed due to nuisance odor ordinances.
The Golden Age of shooting began after the war when retuning soldiers wanted to practice the sport and the military still supported firing teams in National Competition rivalry between the services and allowed civilian participation.
The NRA then, as it does without recourse now, was very instrumental in organizing the competition at Camp Perry called the National Matches. It was very impressive to have the Secretary of the Army and the Marine Commandant watch the competition to see which service would be the “National Champions”. This type competition gave impetus to civilian clubs around the country to build and improve former military shooting ranges as shooting clubs to practice their sport.
Unfortunately the Golden Age of Shooting was coming to and end when I started to shoot competitively.
With the advent of the Kennedy brother assassination members in congress decided to defund the services’ competition budgets in 1968 and military support for the National Matches was vastly reduced.
The population encroachment on ranges would not cease however.
For new ranges, the shooting industry recommended in 1989 that since it was unrealistic and no one could afford to provide the full 3.5 mile SDZ down range, that contained range protection should be designed. Fully contained in urban settings and partially baffled for ranges more removed from development.
That recommendation never applied to existing ranges of any specific configuration and it was left to the engineers and range designers to figure out what specific low cost fix should be implemented to make existing ranges work economically..
The Industry finally addresses this concept in the NRA Manual of 1989 revisions to the prior manual. ‘All bullets will be contained within the ranges property lines”
Prior to the “Source Book”, the design industry had been shocked by a court ruling that closed the Tampa Police Range. A range very important to the competitive shooting fraternity. The Tampa Police Range had for many years hosted the National Match Mid Winters competitions that started the National shooting schedule for the country.
The Nationals at Camp Perry are usually set for July at Camp Perry. The Mid Winters were scheduled for mid February to mid March to allow each State to hold a Regional and a State championship in between the Mid Winters and the Nationals.
The Tampa Police Range (TPR) unfortunately on the police side got a bullet out. Half of the ranges the civilian side had just been re-built as a totally enclosed baffled ranges. The TPR and PC was willing to upgrade the rest of the facility if they would be allowed to operate the baffled portion while improvements were being made. The range needed the cash flow.
The judge however “closed the range” on the basis that the Sheriff testified that a shooter could still shoot to the rear or from the parking lot and hit the city. The Judge shut the range down permanently.
It might be pointed out that the class action suit by the people living in the subdivision down range is said to have been orchestrated by a DEVELOPER WHO COVETED THE RANGE PROPERTY.
The Sheriff who testified as to the range being unsafe, subsequently after retirement, went to work for the developer. A fine high school sits on the site with the developer subdivision behind. “No more Mid Winters”.
Throughout the 70’s and 80’s the concept of “No Blue Sky” expensive ranges had been discussed and applied in design, but is no where really codified.
The “No Blue Sky” concept relies on range rules that require the shooter not to chamber a round until he is an approved position such that when he chambers he can not see blue sky. When this occurs then the bullet can not get directly out of the range if adequate baffling material is used.
This principle then also developed tube ranges and bench rest ranges where the firing line is baffled and a horizontal slit of limited height is provided by relatively thin sheet metal plywood. In both instances, the only thing the shooter sees is the target and the back stop.
More sophisticated baffling methods were shown by the NRA in the 1998 Range Source Book where wood, wood and gravel, and wood and steel, and steel, rubber baffles are shown as acceptable methods of baffles to destabilize or stop the bullet and when coupled with the range rules of “No Blue Sky”, a safe design results.
Another concept change that occurred in the range design industry was the decision not to mention the SDZ’s. It is the very, very rare case where land is available. The concept now is to contain all projectiles within the vertical projection of the ranges property lines in the order to make ranges defensible against trespass law suits.
The only remaining argument now among the designers is the use of the proper materials to achieve the task.
For a firing range with sufficient property it is not necessary to stop the bullet at the baffle. Destabilizing the bullet and causing it to fall within the properties controlled safe zone is sufficient.
If you don’t have a large shooting range parcel or property, more robust baffles are needed, until finally the bullet is contained within the perimeter of the range itself.
The “No Blue Sky” concept is the most economical way to make ranges safer.