[This article was first published in Army Sustainment Professional Bulletin, which was then called Army Logistician, volume 3, number 1 (January–February 1971), pages 20–23. The text, including any biographical note, is reproduced as faithfully as possible to enable searchability. To view any images and charts in the article, refer to the issue itself, available on DVIDS and the bulletin’s archives at asu.army.mil/alog/.]
The mobile warfare concept has mushroomed the magnitude of earthmoving tasks. This problem is in the lap of the Army Engineers who have the mission of enhancing the mobility of friendly forces, restricting the mobility of enemy forces, and performing essential construction tasks under all conditions.
MODERN TECHNOLOGY has come a long way since the turn of the century. Man has learned to fly through the air and to move rapidly across land and has improved his capability to travel on and through the water.
But time has stood still in another equally important area which would cause an army to lose a war, a kingdom to come tumbling down. Man has not yet learned how to move rapidly through and under the earth’s crust.
And Mother Earth could mean life or death to a soldier in combat. Survival for the fighting man still depends to a great degree on how swiftly he can dig himself a hole in the dirt.
Even in this day of the atom and all of the modern weapons of war, the soldier must dig his hole with an entrenching tool (spade or pickax) or bayonet because he is issued nothing else with which to do the job.
It has been said that the shovel is still the U.S. Army’s most versatile earthmover. Our soldiers are still using the same principles today that were used 3,000 years ago to move the earth. In those days the soil was tilled by dragging a crooked stick through it. Now, our foot soldiers and military engineers have more sophisticated equipment, but the methods have not changed. They both go about getting the job done the same way — through brute force. The soldier uses brute force with a shovel or pickax, and the engineer uses that same brute force plus tractive effort to move the soil.
Today, the Army Materiel Command’s Mobility and Equipment Research and Development Center at Fort Belvoir, Virginia, is giving priority to the development of earthmoving equipment during the 1970’s.
Many people probably wonder why the Army is so interested in new types of earthmoving equipment. The reason is simple. Wars require special equipment of all kinds. The earthmoving equipment that was adequate during World War II, for example, is no longer adequate under new concepts of warfare. Although some items of commercial construction are adaptable, the lack of repair facilities, skilled operators and mechanics, and the need for cross-country mobility and air transportability make earthmoving equipment designed specifically for military combat operations more efficient.
Engineers Responsibility
The engineers are responsible for the construction of roads, Air Force and Army aircraft landing facilities in non-strip-landing areas, and hardstands for dispersed storage. They are also responsible for removal of barriers, streamcrossing facilities, and the placement of everything below ground for protection from nuclear blast and radiation. Speed is essential when performing these high priority jobs.
An example is the Army air-landing facilities that are needed to support air mobility and air assault concepts. These facilities must be built in hours, used perhaps only for hours, abandoned, and then rebuilt in new locations. They must be built when and where needed — in forests or mountains, jungle or arctic, in all kinds of weather, and in darkness as well as daylight.
These facilities, which are built to minimal standards from locally available materials, are usually earth strips covered with membrane to repel water and with metal landing mats to increase the load-bearing capability. These air-landing facilities also require clearing, leveling, soil stabilization, control of dust, compaction, and drainage. Landing strips, however, represent only one-sixth of the total area that must be prepared, including runways, taxiways, parking areas, and access roads.
Modern military operations require that some engineer equipment, whether it is earthmoving, excavating, brush clearing, or leveling and compacting, be lightweight, highly mobile off road, air transportable, efficient, durable under all environmental conditions, and simple to operate. It must be capable of performing a number of different jobs. It must be easily repaired in the field by replacing components. Engines must have high horsepower-to-weight ratios. Most of the equipment must be able to swim inland waterways — and all of it must be able to ford 3-foot streams.
New Multipurpose Tractor
One of the most important items of construction equipment on the horizon today is the Universal Engineer Tractor (UET). This multipurpose, tracked, amphibious, 265-horsepower vehicle is capable of excavating and scraping, bulldozing and rough grading, land clearing, hauling combat engineer squads, and transporting their organic tools and equipment. The UET has great maneuverability. As an amphibious vehicle, it can swim at a speed of about 3 miles per hour propelled by its tracks.
Much of the Army’s existing earthmoving equipment is too heavy to move by air. The UET, though, can be airlifted and airdropped by the C-130, but there is still a serious gap in the Army’s capability for rapid localized deployment.
Developing Lightweight Equipment
The Army currently is rushing the development of a family of construction equipment that can either be moved by fixed-wing aircraft or lifted by helicopter. This family of engineer construction equipment is expected to become available to combat-deployed troops in the midseventies.
Beginning in the 1975-76 time frame, the Army plans to be producing a high speed earth excavator based on a completely new technological approach. Called the Repetitive Explosive Device for Soil Displacement (REDSOD), it will have a slotted blade lip that pushes into the soil while a mixture of air and fuel is admitted to a combustion chamber. The fuel ignites and the resulting explosion blows out through the blade slots displacing and casting the soil. It also has been called a “Soil Blaster” with an appropriate acronym — “SOB.”
The REDSOD looks like the answer to the Army’s requirement for quick construction of protective shelters for both conventional and nuclear warfare. It can be used to construct rough road beds or to open waterways through marshy terrain, swamps, and lowlands. It can also be used for flood control and for brush and undergrowth clearance.
Hole-drilling equipment for explosive ordnance disposal has been under development for some time and there also is a priority need for rapid hole-boring equipment to emplace atomic demolition munitions. The current state-of-the-art is limited to hand tools, earth augers, and drills obtainable from commercial sources. These fall far short of Army requirements for mobility, penetration rate, and similar capabilities.
Test Explosive Drilling
Experimental drilling with explosives using shaped charges and mechanical equipment is also being studied by the Army. But even if this technique is adopted, it will still be below the Army’s requirements for speed of emplacement and flexibility in choice of hole dimensions.
Further in the future (1980–85 time frame), the Army hopes to find even better approaches to the hole-boring system. It is presently examining such possibilities as laser beams, ultra-high-velocity fluid jets, and thermal drills.
The Army also sees a future in hypervelocity fluid jets for such military tasks as breeching barriers, rock quarrying, and rock fracturing. Additionally, they could be used in boring for emplacement of explosives, tunneling, and ordnance disposal. The Russians reportedly have found these jets practical for coal mining, rock fracturing, and boring. The Russians claim the jets have a production efficiency of up to 10 times that of conventional rock-breaking hammers.
Army scientists have already begun developing an exploratory model jet mechanism that uses the waterhammer principle for fluid extrusion. Pulses of about 0.02 cubic inches of water can be expelled at a frequency of about six per second at a peak stagnation pressure of about 100,000 pounds per square inch. The mechanism can deliver 800 foot-pounds of impact energy per pulse and uses about 60 gallons of fluid per hour. The pulsed jet is expected to have such great rock-fracturing capabilities that a vehicle mounting this equipment will significantly aid the Army in breeching rock barriers such as those that prevent amphibious landings and restrict the emplacement of atomic demolitions.
Versatility Necessary
Any way the crystal ball turns, the Army’s needs in the earthmoving field are many. It needs machines with the versatility to handle many jobs. More specifically, here are just a few special purpose machines the Army could use now:
- A lightweight amphibious tactical tractor that counterinsurgent forces could use in remote areas. It should weigh no more than 6,000 pounds, have a high earthmoving production rate, and be capable of bull-dozing, land clearing, excavating, hauling, and rough grading.
- A high speed burrowing machine that can dig the tunnels and underground chambers that are necessary to protect and conceal materiel and personnel. It would probably be a high-powered, tracked vehicle with an ultra-high-speed soil drill on an articulated arm extended in front similar to a dentist’s drill.
- A blowdown clearing machine to handle, displace, and remove standing timbers in areas hit by atomic blast. The cutting edge of the plow could be made of high speed chain saws and a retractable chain saw provided for cutting stumps at ground level.
- A cross-country terrain construction machine that is air transportable and can use, process, and finish soil in place to produce a pavement at a rate of 10 feet per minute, 10 feet wide, that would sustain a high volume of traffic. This would be a bonanza for the construction engineer engaged in rapid repair and construction of communications routes, airfields, and supply depots.
- A soil-decontamination machine to remove soil from contaminated areas to minimize the radiation effect from nuclear blast fallout.
- Remote control and mechanical manipulators for equipment that must operate in hazardous or contaminated areas — probably mechanical arms attached to remote-controlled tractors.
Need Many Capabilities
All of the Army’s new earthmoving machines must have a number of capabilities. They must be lightweight, high performance, reliable, and versatile power plants compatible with new mobility concepts in earthmoving equipment. The engines should be capable of operating on all the operational fuels available in a tactical theater anywhere on earth. The gas turbine is perhaps the best power plant built. Certainly, no other power plant can compete with it on a size and weight basis. No other can match its versatility and quick-starting characteristics. And, further, the gas turbine has a multifuel capability, being relatively insensitive to fuel type and quality.
AMC hopes to give the engineer-soldier in the field the earthmoving capability he must have to get the job done on the battlefield of tomorrow. New AMC-produced earthmoving equipment far surpasses the spade and the pickax, but there is still a long way to go.
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