Stretching the Pipeline
A new transfer system keeps fast-moving armies supplied with fuel and water
Today's army relies on fast-moving, mechanized equipment that can sweep across varied terrains to reach an objective before the enemy has a chance to dig in. But armies as far back as Napoleon's have grappled with the fact that the forward speed of a fighting force eventually is restrained by the slower advance of the supplies that sustain it.
For modern warfighters, aging systems that supply critical fuel and water to the battlefield may no longer be mobile enough to support future force projections like those deployed during the early hours of Operation Iraqi Freedom in 2003.
To get water or fuel to the front, the existing Inland Petroleum Distribution System uses 19-foot sections of rigid pipe that must be carried on trucks, unloaded by hand and joined with clamps - and even then, they can leak if the pipe deflection exceeds the allowable angle. This labor-intensive system can advance the supply of fuel only about two to three miles a day.
Engineers and technicians from SwRI are demonstrating a new, highly mobile system for the U.S. Army that deploys four to six times faster, requires fewer soldiers and trucks, and has the ability to control and monitor its own performance and remotely detect and locate leaks from a central command post.
Under contract with the U.S. Army Tank-automotive and Armaments Command (TACOM), the SwRI team has built and demonstrated a prototype Rapidly Installed Fluid Transfer System (RIFTS), which consists of lay-flat hose, deployment and retrieval reels for the hose, pumping stations and a command module complete with a leak detection system.
The lay-flat, reel-mounted hose is deployed from a large, all-terrain tactical truck, and with only three people (truck driver, reel operator, and an observer for safety) it can lay more than a mile of hose per hour. Pumps are installed every three to 10 miles, depending on terrain slope, to maintain flow from the point of origin to the tactical petroleum and water terminals near the battlefield.
RIFTS is deployed in 50-mile sets and can go almost anywhere in the world. Multiple RIFTS sets can be joined together to transport fuel or water over hundreds of miles. It can operate at temperatures from minus 40 degrees to 120 degrees Fahrenheit and at elevations from sea level to 9,000 feet.
SwRI is the developer and system integrator for RIFTS. The major components of the system are purpose-built, but RIFTS makes use of commercial subcomponents when possible to lower overall costs. SwRI is overseeing several subcontractors that are developing and manufacturing some of the components in the system. This establishes supply sources that are capable of manufacturing large quantities of components.
The key component of RIFTS is six-inch-diameter conduit which somewhat resembles fire hose but is larger and much more advanced in design. The RIFTS hose, when compared to standard commercially available hose, represents a four- to five-fold increase in performance in terms of pressure and fluid delivery volume. The use of higher operating pressures and larger diameters with the RIFTS conduit is very important because it greatly reduces the number of pumping stations needed for a given deployment distance.
Specialized RIFTS equipment includes the conduit reels, with a capacity of one mile of conduit per reel. Efficient use of space in the reels, coupled with the lay-flat conduit, results in a three-fold reduction in the number of shipping containers compared to the number of containers required for pipe.
The automated pumping stations use modern subcomponents and efficient packaging to reduce by half the number of shipping containers required for those components. Reducing the number of RIFTS containers is critical to reducing the equipment and manpower needed to deploy the system, which in turn increases operational speed and flexibility.
The central command station remotely controls and monitors all of the pumping stations via wireless digital communications links. Its operator will be able to completely operate and closely monitor all of the pumping stations used in a 50-mile set. Pressure and flow data from the pumping stations are monitored by a system that can detect and locate leaks as small as 0.4 percent of the total flow rate, or less than four gallons per minute when RIFTS is flowing at its full capacity of 800 gallons per minute. The existing, rigid-pipe system has no leak detection capability.
Starting with work in the late 1980s, the Institute's Mechanical and Fluids Engineering Department has been instrumental in developing modern line break detection methodologies for gas and liquid pipelines. SwRI researchers formulated techniques based on pipeline fluid dynamics to replace the simpler "rate of pressure-drop" methods that had been in common use. The older methods were often de-tuned by their users to avoid frequent false alarms, with the result that true line breaks often went undetected.
The algorithms and techniques pioneered by SwRI have found their way into microprocessor-equipped automatic closing valves and updated valve spacing criteria used by the gas pipeline industry to maximize the probability of detection and minimize product loss.
The RIFTS mission
RIFTS was designed to improve on the existing tactical bulk fuel and water transfer system in a number of categories. An important aspect of that mission is rapid deployment - the ability to not just lay up to 20 miles of hose line per day but also to retrieve it at 10 miles per day. Delivery capacity was established at 850,000 gallons of fuel or water per day using pumping stations located 3 to 10 miles apart, depending on terrain. Uphill pumping would require more frequent boosts, while fewer pumping units would be needed to transport fluids over relatively flat land.
The Army also desired a reduced logistical footprint: fewer containers to ship, fewer soldiers to deploy and operate the system, and fewer problems with reliability and maintainability. TACOM also sought better situational awareness and system control over the fluid delivery process.
The four major component assemblies envisioned for RIFTS include emplacement and retrieval devices (ERD) or "hose reels," collapsible high-pressure conduit, automated pumping stations, and a command and control module, as well as support equipment.
Under a two-year, $13.6 million contract, SwRI has been tasked with developing component performance specifications; performing competitive source-selection for ERDs, automated pumping stations (APSs) and high-pressure conduit, or hose, while also overseeing their development; developing a command and control module that includes leak detection; developing the support equipment required for deployment; integrating RIFTS into a complete system for evaluation and testing; developing and integrating system documentation; and developing training systems for soldiers in RIFTS operation.
SwRI is developing the Command and Control Module (C2M), with the leak detection system, as well as conduit repair kits, displacement and evacuation kits, manuals and training for RIFTS operators. Other major components, such as the ERDs, conduit and automated pumping stations, are to be supplied by subcontractors.
Component development and testing
RIFTS conduit must have a minimum 6-inch inner diameter, be able to lie flat and to be wound onto a reel, and to be supplied in 500-foot sections that can be joined using quick-connect, field-repairable couplings.
A number of outside conduit suppliers were identified, and five potential suppliers provided samples for environmental and performance testing at SwRI. Of the five vendors, one has developed a hose that is considered a good candidate for RIFTS adoption. Its conduit is very close to meeting the RIFTS specifications, and the vendor is developing methods to raise performance even further. By June 2005 the vendor will be fabricating five miles of limited production conduit, with another five miles to be supplied by September 2005. This conduit will be combined with the hose reels and support equipment into a 10-mile system that the Army will subject to production acceptance testing and limited user testing. The tests are to be complete by December 2005. Full-scale production is scheduled to begin in 2006, and expected to total at least 200 miles.
An ERD prototype has been designed, fabricated, delivered and tested with the Heavy Expanded Mobility Tactical Truck (HEMTT), a 13-ton capacity, 8-wheel-drive vehicle capable of operating through almost any terrain. The HEMTT will be used to move RIFTS in the battlefield. RIFTS conduit deployment and retrieval operations have been initially tested with the ERD. Eleven additional units will be delivered and combined with the 10 miles of conduit. Meanwhile, the prototype APS, powered by an industrial diesel engine, also has been fabricated and delivered.
The Command and Control Module, developed by SwRI, is the central command point for RIFTS operations, including system controls and leak detection. The module is designed to be integrated into a standardized command post system mounted on a high-mobility multi-wheeled vehicle (HMMWV). It controls all functions of automated pumping stations, provides real-time monitoring of the system's status and offers the RIFTS operator a graphical user interface. The module uses ruggedized PC computers and flat-panel displays with a touch-screen interface, using Windows® operating system. It provides wireless data links and voice communication to the automated pumping stations for contact with troops involved in on-site maintenance, repair, support or security.
The command and control module identifies and reports leaks along the conduit, including size and location, and provides immunity from false alarms. It does these using only pressure and flow rate data sent from the APS.
SwRI engineers built a small-scale technology demonstrator system to test remote pump operations, status and leak detection and demonstrated the unit successfully at Fort Pickett, Virginia.
Under steady-state operation, the leak detection software was able to determine that a leak had occurred within a minute or less after it began if the leak amounted to 3 percent of flow or greater. At its sensitivity limit, the system detected leaks as small as 0.3 percent of flow. It also was able to determine a leak's location within 10 percent of the conduit length for leaks larger than 5 percent of flow. Lessons learned from the small-scale demonstrator are being incorporated into full-scale RIFTS development.
Future development of RIFTS
During the remaining year of the TACOM contract, SwRI team members will begin integrating and testing the conduit, the emplacement and retrieval device, the automated pumping station and the command and control module, integrating the command and control module into its HMMWV-mounted shelter, and finalizing the digital battlefield communications system. Researchers will use future testing to document lessons learned, strengths and needed improvements, and move RIFTS toward production as quickly as possible.
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Published in the Spring 2005 issue of Technology Today®, published by Southwest Research Institute. For more information, contact Joe Fohn.