Stakes in the Sand: Surveying in the Gulf War

In 1990, US forces arrived in the Persian Gulf with a cornucopia of navigation technologies: not just GPS but also LORAN, TACAN, TERCOM (for cruise missiles), and inertial navigation systems which used laser, electrostatic, or mechanical gyroscopes, as well as old-fashioned manual tools like maps and compasses. So why were US surveyors heading off into the Saudi desert?

The surveyors were from the 30th Engineers Battalion (Topographic), which was deployed to provide map production and distribution, surveying, and terrain analysis services to the theatre. The survey platoon’s work was being done on behalf of the Corps and divisional artillery, which had their own particular navigational needs. Unlike fighter or helicopter pilots, field artillery gunners didn’t have the opportunity to see their targets and make last-minute adjustments to their own aim. Unlike bomber crews or cruise missiles, their fire missions were not planned well in advance using specialized materials. To provide precise positioning information to the guns, each artillery battalion in the Gulf was equipped with two Position and Azimuth Determining Systems (PADS), truck-mounted inertial navigation systems that keep an ongoing track of the unit’s positions. At the heart of the PADS was the standard US Navy inertial navigation system, the AN/ASN-92 Carrier Inertial Navigation System (CAINS).

Like all inertial navigation systems, PADS had a tendency to drift over time. That meant that it required regular refreshes using a pre-surveyed location, or control point. The initial specifications for PADS were to achieve a horizontal position accuracy of 20 meters over 6 hours and 220 kilometers. Actual horizontal accuracy seems to have been far better, more like 5 meters. One reason for the high accuracy was that, unlike an airplane, the vehicle carrying the PADS could come to a complete stop, during which the system detect and compensate for some of the errors by the accelerometers in the horizontal plane.

Unfortunately, the US had exactly one control point in Saudi Arabia, at Dharan airbase (Army Reserve historian John Brinkerhoff says this and several other point surveyed were done with “Doppler based methods.” I assume that means using the TRANSIT satellite system, which determined location on the basis of Doppler shift). Starting from that control point, the 30th’s surveyors extended a network of new control points northwards and westwards towards the Iraqi border. Conventional line-of-sight survey methods would have been too slow, but the surveyors had received four GPS receivers in 1989 and soon got more from the Engineer Topographic Laboratories to equip a follow-up team of surveyors. Eventually, their survey covered 10,000 square kilometers and included 95 control points. Relative GPS positioning took about two hours (according to Brinkerhoff) and offered accuracy to about 10 centimerers (compared to 17 meters for regular GPS use). Absolute positioning – done more rarely – required four hours of data collection and provided accuracy of 1–5 meters.

When the ground war began on 24 February 1991, the two survey teams tried to stay ahead of the artillery, which meant driving unescorted into the desert and marking new control points with steel pickets with reflectors (for daytime) and blinking lights (for night-time). Providing location data through headquarters was too slow, so the surveyors took to handing it directly to the artillery’s own surveyors or just tacking it to the pickets. By the ceasefire on March 1 they had surveyed all the way to 30 km west of Basra. Where the artillery outran the control points they used their own GPS receivers to make a “good enough” control point and reinitialized the battalion PADS there, so all the artillery batteries would at least share a common datum. One thing PADS could do and GPS couldn’t was provide directional information (azimuth), so units that outran their PADS capabilities had to use celestial observations or magnetic compasses to determine direction.

What the 30th Battalion and the artillery’s surveyors did in the Gulf was different enough from traditional survey methods that the some in the army already used a different phrase, “point positioning,” to describe it. In the 1968–1978 history for the Engineer Topographic Laboratories, which designed army surveying equipment, PADS was one of three surveying and land navigation instruments singled out as part of this new paradigm (the others were a a light gyroscope theodolite with the acronym SIAGL and the Analytical Photogrammetric Positioning System).

Brinkerhoff tells the story of the 30th’s surveyors as the meeting of the high and low tech, but the work really relied on a whole range of technology. Most of the GPS surveying was relative positioning that was anchored to previous Doppler surveying. Position and azimuth information was carried forward by inertial navigation, and the position of the firing battery was paired with target information from a forward observer equipped with GPS, an inertial navigation system, or a paper map or from aerial photography which could be interpreted using the aeroplane’s own navigation system or a photointerpreter’s tool like APPS. GPS surveying and navigation did not stay wrapped up with all these other navigational tools for long. The technology was flexible enough to be used in place of many of them. But in the early 1990s, GPS’s success was contingent on these other systems too.

Sources Notes: The story of the 30th and its surveyors appears in John Brinkerhoff’s monograph United States Army Reserve in Operation Desert Storm. Engineer Support at Echelons Above Corps: The 416th Engineer Command (printed in 1992). Further details appear in the Army Corps of Engineers history Supporting the Troops: The U.S. Army Corps of Engineers in the Persian Gulf War (1996) by Janet A. McDonnell and “The Topographic Challenge of DESERT SHIELD and DESERT STORM” by Edward J. Wright in the March 1992 issue of Military Review. Reflections on how the artillery used PADS and GPS in the Gulf come from the October 1991 issue of Field Artillery, a special issue on “Redlegs in the Gulf.” Technical details for PADS are from the ETL History Update, 1968–1978 by Edward C. Ezell (1979).

A Tale of Two Keystone States

An auxiliary crane ship, the SS Cornhusker State, in 2009. US Navy by Petty Officer 1st Class Brian Goy. DIVIDS Photo ID 185724.

In the later years of the Cold War, the US Navy recognized the need to revitalize its seagoing transport capacity. During the Second World War, the military had built a massive fleet to support transatlantic and transpacific campaigns. Mothballed after the war, much of it had rotted away by the time reconstruction began under presidents Nixon and Carter and accelerated under President Reagan. One necessity for the new fleet was equipment to move cargo – especially containers – from ship to shore. After experiments with lifting by helicopter or balloon, the Navy settled on fitting a series of cargo ships with heavy cranes to unload cargo in ports that lacked the necessary infrastructure. The first ship to be converted was the SS President Harrison, previously operated by American President Lines, which was renamed the SS Keystone State (T-ACS-1) upon completion of its refit in 1984.

The Barge Derrick Keystone State (BD-6801) being towed by two Army Small Tugs during an exercise at Joint Base Langley-Eustis, Va., Aug 6, 2013. (U.S. Army photo by Spc. Cal Turner/Released) DIVIDS ID 990511.

Confusingly, the T-ACS-1 is not the only US military crane watercraft named the Keystone State. In 1998, the US Army launched a engine-less crane barge BD-6801 with the same name, chosen to honor the 28 soldiers from Pennsylvania’s 14th Quartermaster Detachment killed in a SCUD attack during the first Gulf War (in this instance, BD stands for Barge Derrick). Operated by the Transportation Corps, the BD-6801 was built to help unload military cargo in any of the many ports around the world unequipped to handle the cargo. It carries a single crane with a reach of 175 feet and a lift capacity of 115 long tons which, unlike the cranes on previous army barges, is able to lift a 60 ton M1 tank off of a cargo ship.

Between 1985 to 2005, at least one Army floating crane like the Keystone State was always aboard the MV American Cormorant, a float-on/float-on (FLO/FLO) heavy lift ship at Diego Garcia that carried a package of Army watercraft for operating a damaged or unequipped port. The American Cormorant and its cargo deployed to many major crises as part of the army response, including the first Gulf War and Operation RESTORE HOPE in Somalia. Until the launch of the Keystone State, the crane barge carried aboard the American Cormorant was one from the BD-89T class, with an 100 foot reach and an 89 long ton (100 short ton) capacity.

The American Cormorant en route to the Gulf. Note the two BD-89T cranes on-board, only one of which was used in operations. From Operations Desert Shield and Desert Storm: The Logistics Perspective (Association of the United States Army Institute of Land Warfare, 1991), p.12. Courtesy of the AUSA website.

It was a BD-89T barge, the Algiers (BD-6072), which was deployed to be used by the Army 10th Transportation Battalion (Terminal) during the Gulf War. In addition to performing more than 1,500 lifts in Saudi ports, the Algiers was used to help clear damaged Kuwaiti ports of obstructions – harbor clearance being a mission shared between the US Army and Navy. After having built-up an extensive salvage force after the Second World War, changes to salvage doctrine meant the US Navy only sent one salvage ship and no heavy-lift gear to the Gulf. Commercial salvors being paid by the Dutch government took up much of the slack, but there were limits to what the contractors could do. With rental fees for barges and cranes running as much as $150,000 a day for a 600 ton Ringer crane barge, the Americans ended up mostly going without the heaviest equipment. The biggest harbor clearing lift involving the Algiers was a sunken Iraqi Osa II missile boat in the Kuwaiti port of Ash Shuaybah. Though small by seagoing standards, the Osa II was 127 feet long and displaced almost 200 tons in standard load. Even in combination with a quayside 140 ton crane, the crane barge couldn’t lift the ship whole. Only after army divers cut off the still-life missile launchers could the boat be raised. Looking back at the operation in the navy after-action report, perhaps with a little bit of envy, one of the navy salvage engineers called the army crane “very workable.” Other sunken craft the divers lifted at Ash Shuaybah, with or without the help of the crane, included a 90 foot sludge barge and two other boats.

The deployment of the Algiers during the first Gulf War is only the tip of the iceberg when it comes to the military roles played by American floating cranes, which since the conversion of the battleship Kearsage into Crane Ship No. 1 have worked to construct warships, salvage sunken submarines, and clear wrecks from the Suez Canal.

Source Notes: Much of the information for this post came from various sources around the internet, and in particular the website for the US Army Transportation Corps’ history office. The Corps’ 1994 official history, Spearhead of Logistics, was also useful. Details on the salvage operations during the Gulf War came mostly from the two-volume US Navy Salvage Report: Operations Desert Shield/Desert Storm, printed in 1992 and available online at the Government Attic (volumes one and two); the report’s chronology was the only place I was able to find which US Army crane barge was actually operated during the war.

Combat-Ready Kitchen

Current, 2015

Combat-Ready Kitchen by Anastacia Marx de Salcedo (Current, 2015)

Anastacia Marx de Salcedo’s Combat-Ready Kitchen is an entertaining look at the work of the US Army’s Natick Soldier Systems Center that manages to pack in a lot of the science behind food processing and preservation. The research sponsored or done by the Army since the Second World War has led, de Salcedo shows, to a lot of the techniques behind easy-to-prepare, ready-to-eat processed foods. On the more frivolous side, both Cheetos and the McRib trace their origins back to military products. More seriously, products like intermediate-moisture foods, energy bars, and plastic packaging all originate at least in part from that work.

De Salcedo frames her story by talking about the remarkable impact that Natick, which has a relatively small budget, has on the products that the commercial food industry, leading to the question of whether we really want us and our children to be eating like Special Ops. The pervasiveness of military-sponsored food research is certainly true, but casting the question as one that has anything to do with military sponsorship seems less than useful. Yes, Natick wants to have its developments commercialized – to lower the cost of production and increase the availability of supplies. But the US economy is littered with industries where the military played a formative influence and has then seen its influence dwindle. Just look at the US merchant marine (long subsidized and hired to keep it available for military purposes), airline industry (ditto, via the Civil Reserve Air Fleet), electronics, and computing (and leading to articles with titles like “Five Reasons Why Silicon Valley Won’t Partner with the Pentagon”).

Our supermarket shelves are filled with products with a military provenance not because Natick is remarkably good at influencing the food industry (though they are good), but because North Americans crave the rugged, imperishable, and cheap products that also make sense for the military. We may not have the foods that would be best for us, but it seems that – for better or for worse – we have the foods we want. That might change if someone could make the idea that health and food security was a national security issue stick. But that’s a whole separate conversation would cost a lot more than the fairly modest budgets the US military puts into food research.