Armor Operations and Training in Korea

Armor Operations and Training in Korea by Lieutenant Colonel Oleh B. Koropey Enemy armor, and our inability to stop it, was a decisive factor in the 1950 Communist plunge down the Korea peninsula to the Pusan Perimeter. Our own armor was a key element in the defense of that perimeter, and later in the United Nations (UN) counteroffensives to win back the lost real estate. Tanks provided mobile, powerful direct and indirect fires, protecting the infantry by day and being protected by the infantry at night. Much has changed during the ensuing 30 years, but armor remains a critical ingredient in the defense of South Korea, especially in light of AirLand Battle concepts.

This article discusses some practical aspects of combined arms in Korea, based on experience and experimentation by 2d Infantry Division and associated Republic of Korea (ROK) tank units. The lesson that stands out in Korea is not new, but the types of terrain and enemy there make it especially important

- that tanks, in order to survive, need to be part of a combined arms team.

Geography Korea is dramatically different from most countries where U.S. armor is stationed, but bears some similarity to other places in which U.S. armor may have to fight, like parts of Southwest Asia. It’s like the West Virginia hill country in topography and climate - very mountainous with steep slopes often rising to 800 meters or more. The slopes are sparsely vegetated, generally covered with short brush, and in the winter are practically bare. Most of the people live in the river valleys and flood plains and this is where most of the roads are. Tank movement is usualIy limited to these low areas. Almost all flat areas and many of the lower slopes are cultivated, usually with rice paddies. You get the impression (through all your senses) that every inch of land on a slope less than forty-five degrees is intensively fer-tilized and farmed. The paddies are considered too soft for tank movement during much of the year; they are trafficable by tanks only during the coldest months of the winter. (This will be discussed in more detail later.) Except during the summer monsoons, the weather is predominantly clear. The frequent fog and mist of Germany are not prevalent in Korea.

The Defile Problem The biggest challenge of attacking with armor in Korea is coping with defiles. Tanks must move along narrow valleys with steep, high slopes, often on a one-tank front. Although certainly not easy, the defile problem was not critical during the Korea War because the enemy lacked lethal, highly portable antitank weapons. But today’s enemy - operating from those same superior vantage points, hidden and dug in (granted, it’s tough to dig in those rocky hills) - has 3,000-meter antitank guided missiles, numerous antitank guns, recoilless rifles, and rocket propelled grenade launchers. He can make the defiles into effective tank killing grounds, unless armor columns skillfully employ combined arms and a few other tricks.

One answer is to clear the slopes ahead of vehicles in the defile with infantry walking along the ridges. In this combined arms approach, the armor provides direct-fire snp-port to the infantry clearing force. This is thorough, but awfully slow. A faster variation is to send an armor vanguard ahead of the main armored column, reconnoiter by fire, and send infantry up to clear the hills only when and if the vanguard draws effective antitank fire. Movement by bounds, with one element always in position to observe and instantly return fire, further enhances security, at the price of slowing things down.

Helicopters can be a great help. During decent flying weather they can comb the hillsides ahead of armor columns, search out the enemy, and allow plenty of reaction time for using smoke, working the area with artillery and/or air, or sending up the infantry. The use of scout helicopters in this role, coupled with gunships to make the kill, was an effective technique in exercise Team Spirit 83. Helicopter usefulness obviously drops off in bad weather or darkness, but so does the enemy’s ability to shoot long-range antitank weapons. Helicopter crews now train to fly with night vision goggles, improving their night capability somewhat; but even with this aid, the ability to observe at night remains limited. (If the enemy gets attack helicopters in Korea, our defile problem will become much more difficult). The defile problem demands smooth teamwork between tanks and infantry down to the lowest level. To achieve this, 2d Infantry Division light infantry soldiers frequently practiced the seemingly simple actions of mounting, riding on top of, dismounting, and communicating with tanks. Tankers were conditioned to such hazards as traversing a turret while carrying externally mounted infantry, and firing sabot ammunition over friendly troops. The “Legs” became potentially as mobile as mechanized infantry (albeit with considerably more vulnerability). The general idea was to transport them rapidly and, as the first shot was fired, to dismount them to maneuver against the enemy on the slopes in coordination with tank fire. Properly trained, and employing I . available artillery and air support, such a team can neutralize the enemy on the hillsides.

Despite the recognized need for tank-infantry teams in a defile situation, I feel it quite likely that a tank company will have occasion to move through defiles without the necessary infantry attachments. There may be cases where the pure “bold mounted thrust” through the defile without the hill-clearing precautions is successful; but when effective antitank fire stops the column and the tankers can’t neutralize it with mounted weapons, the tankers themselves must be trained and ready, in both a physical and psychological way, to respond. One possibility is to dismount the rear two platoons with submachine guns and M60D machine guns (when equipped with M48A5s) to clear the hillsides and allow mounted elements to move through. Thus, in Korea, tankers must be capable as infantry fighters, as well as expert users of their tank armament. This places a heavy premium on physical fitness and toughness, and adds the dismounted training requirement to an already packed training program. Another technique to reduce the potential effects of long-range antitank fires while moving through defiles - or anywhere else for that matter - is to move under conditions of limited visibility, at night or using smoke. This lesson was repeatedly confirmed in MILES force-on-force exercises. The trade-offs are that night maneuver is invariably slower and more difficult to control, and smoke is subject to the whims of the wind, and can blind you as well as the enemy. With M60A3 tank thermal vision devices, we can move better under these conditions than ever before without being seen by the enemy. Only noise gives away our movement.

Communications are difficult in this kind of terrain. It’s hard to talk over the hills. This situation forces frequent use of relay stations and radio retransmission.

Barrier Obstacles The defiles and other armor avenues are well-known by both friend and foe and are blocked as a matter of course. Obstacle breaching operations are therefore de rigueur. Engineers must be well forward in every column, or they will not be able to get around the traffic to do their job. They often travel in the vanguard, in the personnel carriers of attached mechanized infantry, or are sent far ahead with scouts to find and clear obstacles. Armored vehicle-launched bridges (AVLBs) and combat engineer vehicles (CEVs) are also prudently placed near the column front in a narrow defile. must be trained in mine-clearing and obstacle-breaching to avoid undue dependence on cross-attachments. Battle drills focus heavily on breaching operations involving close teamwork among tanks, infantry security teams, and engineer equipment and personnel. Tanks equipped with bulldozer blades, an albatross in most units due to reliability problems, are at a premiumin Korea. AVLBs are used not only for spanning ditches, but also to build ramps to the top of obstacles such as tank walls. AirLand Battle Doctrine in Korea The AirLand Battle emphasizes the offensive. If this opportunity arises for US. ground forces in the defense of South Korea, it may involve breaching extensive complex obstacles like those found in a primary defensive line. To succeed in such operations we must know exactly what the obstacle belt consists of, and then plan carefully, rehearse, and execute the breaching operation with the full “orchestra” of engineers, armor, infantry, smoke, artillery, and air. Much will depend on the specific sequence of obstacles encountered. 2d Division engineers have developed an obstacle breaching course that tactical units use every year. As an example of the training for such operations, consider the following situation presented to company teams of 1st Brigade, 2d In-ENEMY LIGHT INFANTRY f h ‘t. c 15’ANTlTANU

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Complex Obstacle Breaching Exercise 1st Bde, 2d ID Company ARTEPs January, 1983 Figure 1 fantry Division, during the attack phase of their January 83 ARTEPs. The complex obstacle is sketched in Figure 1. It consisted of mined wire entanglements, followed by an antitank ditch, more mines, then a water obstacle, and finally a 15-foot high antitank wall. A platoon of enemy light infantry defended the team’s objective area. One tactical solution to the problem was as follows: Tanks initially went into overwatch positions. A platoon of mechanized infantry moved in near the closest wire entanglements, dismounted, and established close-in security. At the same time the area was smoked. An obstacle-breaching line charge was pulled into position by an armored personnel carrier and it blasted a 70-foot-long, 15-foot-wide strip through the wire and mines. Next a mineroller tank advanced through this lane up to the antitank ditch. Its task was to confirm that the line charge had cleared a safe lane for the first AVLB which followed. The first AVLB then pulled up and spanned the antitank ditch. The mineroller tank then crossed this AVLB and continued across the ford to the base of the tank wall. Mechanized infantry then followed in APCs to the base of the tank wall where they climbed from the tops of their vehicles on each other’s shoulders to seize the top of the wall, clear off enemy infantry, and provide local security for the crossing. (Wall-scaling ladders had been tried in rehearsals, but rejected as too cumbersome.) A second AVLB followed the infantry to the base of the tank wall where it extended its bridge to the top of the wall, forming a ramp.

Meanwhile, the lead tanks were leaving their overwatch positions. As soon as the ramp was in place they drove up it, crested the tank wall, and drove down the relatively gentle slope on the other side, to establish a foothold on the far side of the complex obstacle. One problem encountered was water freezing on the ramped AVLB from the vehicles exiting the water, making it slick, but this was solvable with sand. The keys to such an operation have to be well-rehearsed; speed and timing are necessary to avoid a column of tanks in the open, queued up at the obstacle.

The Light Infantry Brigade Problem Enemy commando-type light infantry brigade (LIB) forces pose a unique challenge to U.S. armor in Korea. North Korea has invested heavily in light, mobile, elite troops who could be air-dropped, infiltrated, or amphibious-landed behind friendly lines to wreak havoc in conventional formations, command posts, logistics facilities, and bases. Because of the large number of these troops, close-in security becomes a major challenge for tank units. There will never be enough infantry available to provide sufficient attachments for adequate close-in security. So, in Korea, tankers must be capable of providing their own close-in security. Tank crews must be able to man their own observation posts and listening posts, and must be able to patrol and fight dismounted if necessary. They must be at home on the ground. A significant part of training during the poor-tank-trafficability summer season was devoted to dismounted small unit operations by tankers armed with sub-machine guns and the loader’s M60D machine guns on M48A5 tanks.

One technique for close-in security of armor which proved effective in exercises is called “the old in and out.” During daylight and good-visibility conditions, tanks are spread out to the maximum while maintaining visual contact (50 to 100 meters as a rule of thumb). This reduces vulnerability to enemy artillery (of which he has much) and air support (of which he has less). Observation posts are put out on commanding ground to maintain security. During darkness and limited visibility, vehicles are pulled in much tighter (10 to 30 meters). This is done just at dark, and timing is important. A fine-tuned surveillance plan ties together night vision devices, platoon early warning systems, ground surveillance radars, patrols, and listening posts into a tight-knit 360-degree perimeter.

The enhanced night vision features of the M60A3 tank improve our capability to observe and shoot at night, but the limited field of view makes them far from a total solution. Constant alertness against infiltrators remains a major challenge.

The LIB threat and the likelihood of ambush by infantry makes anti-personnel flechette (APERS) ammunition very useful in Korea. Consequently, this ammunition is retained in the tanks’ stowed load and crews are trained in it use. Camouflage of Tanks US.

Tankers in Korea are probably among the best in the world at camouflaging their vehicles. This is probably a spin-off from the ROK Army, who are masters of the art. The idea is to do more than go through the motions to “camouflage” tanks; the key is to make them invisible. These camouflaging techniques can be broken down into categories of “moving” and “stationary.” Moving camouflage is necessary when the tanker knows he will have to displace instantly. It involves attaching rice straw, branches, brush or other matter in such a way that the tank can move, traverse the turret, and shoot instantly.

The second category is stationary camouflage in which the need for instant movement is not as critical as the need for thorough concealment. This involves extensive use of camouflage nets, along with other means. Whenever do-able, tanks are positioned next to hillsides so that the net-covered vehicles look like an extension of the hillside. Rice straw, branches, or other appropriate vegetation is placed over the net to further blend the visual image into the terrain; openings are left to allow sighting and shooting the guns.

In the winter, depending on the completeness of the snow cover, either white or regular camouflage nets are used. These can be further enhanced by weaving other colors of cloth strips into them and cap-ping with brush or vegetation as appropriate. These covering techniques for snow conditions are more practical and effective than painting the tank with a whiteflour-water solution. Whether moving or stationary, special care is necessary to break up those distinct outlines (like gun tubes) which assist the enemy in target acquisition and coincidence ranging.

Fording and River Crossing Tanks in Korea often drive along river beds and cross rivers with and without the use of bridges. In training, we used fords whenever possible to reduce safety risk to civilian traffic and to avoid wear and tear on bridges. This also makes tactical sense, since bridges will most likely be targeted by enemy artillery and air. When we had to cross a bridge and were not sure of its classification, we often reinforced it by laying an AVLB over it. Wide ford sites which exceeded maximum allowable fording depth (4 feet) were lined by our engineers with multiple AVLBs. The engineers placed overlapping sections in the water, end-to-end, across the too-deep part of the ford. In Exercise Team Spirit 82, we emplaced six AVLBs in this way to get a tank battalion across the Han River, which had a depth of 5% feet at its deepest point at the fording site. Tank movement in and along stream beds is not only possible but frequently the only way to go. The beds are generally rocky bottomed and offer a firm base, (unlike in many other parts of the world, where getting near a stream bed runs a high risk of a tank miring down). During most of the year, most streams and some rivers are shallow enough for continuous movement of tanks along them. Since the roads often parallel streams along the bottom of valleys, a tank unit often advances down a valley on a two-tank front, one column on the road, the other in the stream bed. An uninitiated aggressor may not be aware of the armor trafficability of a river bed; as was demonstrated in Team Spirit ’85, this movement technique offers an attractive opportunity for surprise.

Tankers and their combined arms teammates must be attuned to the special demands of frequent movement through water. This includes frequent changing of grease in suspension systems; and care to ensure availability and proper functioning of all hull access plates, drain plugs, escape hatches, and seals. A thorough reconnaissance of the river’s depth and bottom conditions prevents surprises such as sink holes. Scouts or engineers in hip boots with a strong rope tied around them are a good way to do this. The simple matter of marking the reconnoitered fording lane for a night crossing requires a bit of forethought to ensure adequate poles and flashlights with filters. During peak monsoon rainfall (maybe once a year), the shallow streams fill up very rapidly and can become literally raging torrents in a matter of hours. During heavy rain, water levels need constant watching, and units in stream beds must be ready to move quickly. Unfortunately, many assembly and laager areas have to be in stream beds because they are the only flat areas large enough to hold the unit. Tank Driving Driving a tank in Korea requires unusual skill, alertness, guts, and adaptability in today’s environment. Due to the clogging of roads by refugees, we will require these qualities in quantity in war. Korean civilian drivers are either ignorant of the hazards of sharing a road with tanks, have little regard for their own safety, or both. When driving on roads, tankers must take extraordinary measures to protect civilian traffic and pedestrians from the tanks. Narrow, bumpy roads and heavy civilian traffic -mostly crowded buses, overloaded trucks and taxis - combine to demand an unprecedented level of defensive driving from tankers. Off-road conditions vary with the season. from March through November the paddies are soft, and driving a tank over them risks bog-ging in the mud. But totally avoiding paddies during this time means writing off some significant maneuver opportunities. Commanders should be prepared to mire a few vehicles in order to learn the full extent of tank trafficability at any given time or place. Drivers must be given opportunities to experiment with off-road mobility and develop the skills to negotiate semi-dry paddy areas.

Moving over paddies may require a dismonted reconnaissance of the route, or even ground-guiding vehicles over difficult spots, sometimes for miles. It helps to avoid “tracking,” that is, tanks should cut separate paths through soft areas rather than follow in the tracks of the tank in front of them. During the cold weather months, there is little excuse for not maneuvering over the paddies other than consideration for maneuver damage to paddy dikes and wear-and-tear on the vehicles and crews from cresting over, then dropping down off a dike. Well-trained drivers can traverse most of the flat land in Korea during the winter months and, given their heads, could probably traverse much more terrain than they are allowed to try in the warmer months.

It is probably worth mentioning that taking more risks in terrain trafficability will demand well-trained, properly-equipped recovery crews, both in the M88s and in the tanks.

Tank Gunnery in Korea The Korean battlefield requires a versatile tanker capable of employing all his weapons in all directions against a variety of targets. Enemy tanks, in themselves, will probably constitute a manageable portion of the overall target mix because North Korean armor, like ours, is quite limited in its avenues of approach; and because, although formidable, North Korean tanks are not the most capable in the Communist bloc.

The limited avenues of approach simplify defensive planning. The defile problem becomes the enemy’s problem, and our challenge becomes one of positioning our tanks for maximum standoff, dispersion, and cover. Up to 4,000 meters line-of-sight can sometimes be obtained with careful reconnaissance (usually dismounted) of firing positions and routes to get a tank up into them. Range cards and accurate ranging skills pay a premium in these long standoff situations. (The M60A3’s laser rangefinder will be a big plus here.) More typical engagement ranges are 1,000 to 2,000 meters along valleys, and from 0 to 1,000 meters in built-up areas and other restricted terrain. Increased urbanization and a national emphasis on tree planting will contribute toward reducing these engagement ranges in the future. Since the enemy will have long-range antitank weapons, we must be able to suppress or kill these weapons at the same or longer ranges. A 2,000 to 3,000-meter HEAT, APERS, or HEP engagement to knock out an enemy ATGM on a hillside is quite likely; and target acquisition skills will be very important. At the closer ranges, it will be possible to engage effectively with machine guns. We tailored our gunnery ranges to this type of situation and emphasized fast, accurate machine gun fire to both point and area targets, often high up on hillsides. The loader’s M60D machine gun offers an additional weapon for this purpose. During the Korean War, the enemy used the night to his strong advantage; but today, our superior night observation equipment, used by properly trained crews, should give us a distinct upper hand in the dark. Now we need extensive night gunnery training to learn to exploit the last iota of utility from this new equipment. One training challenge is learning to transfer target information from other members of the tank crew to the gunner. This requires some careful thought and experimentation.

In the event of a breakthrough into the enemy’s rear areas, a great smorgasbord of targets would appear. Machine guns, APERS, and HEP would be the workhorses against personnel, buildings, and materiel. Thus, gunnery training must retain a good balance between tank targets as well as other types. Indirect fire was a frequent role for our tanks during the Korean War. This capability should be retained if possible, but not at the expense of the previously mentioned gunnery skills. The necessary references and equipment should be kept available, and, if time and ammunition allowances permit, then classes and dry fire, followed by live indirect fire, should be conducted. (We, frankly, couldn’t find time to practice indirect-fire.) The M 4 9 4 (APERS) Cartridge During a visit to Egypt after the Yom Kippur War, the Army’s development engineer for the M494 was told by an Egyptian general that the APERS rounds used by the Israelis were very effective against Sagger antitank guided missile teams.

Actual firings of the same round in Korea in the early 1980s did not impress our tankers. They did not seem to put very many holes in the targets. This is due to a lack of understanding of what the round is designed to do, inadequate training with the round, and possibly some shortcomings in the rounds themselves due to very low turnover and consequent long storage.

The round was originally designed for countering human wave attacks. It dispenses 5,000 match-sized steel darts (flechettes) at a designated range in about a 20-degree fan. Dispersion patterns are such that you can expect to see only one or two flechette holes per 10 square feet of target area (about a 3 by 3 foot square. Cranking the correct target range into the fuze before firing is critical because the round is designed to disperse about 75 meters before the target, and the flechettes spread out to an optimal pattern in those last 75 meters. Setting too long a range can mean the round disperses after it passes the target, while setting it too short means too much dispersion on target with the possibility that no flechettes hit.

The design engineer emphasizes the following: Crank in proper range. (This should be much easier with the M60A3 laser rangefinder.) Do not adjust for standoff. (The round does this automatically.)

Turn the fuze only clockwise to set the range. If you pass the desired range setting then continue around again clockwise until you get it right. (If you turn the fuze counterclockwise you induce backlash into the gears and get an inaccurate setting.)

A more subtle point is that t density of flechettes is high6 about 18-20 feet left or right oft point of aim, so the experts mig consider a little aimoff to get mi imum density on target.

The main message is that AF’ERS requires quite a bit of training to ensure effective use, but the capability should be worth the effort.

Maintenance

Before closing, it is important to pass along some of the maintenance-related idiosyncrasies of operating armor in Korea. The cold Korean winters, with temperatures dropping occasionally below zero degrees Fahrenheit, and averaging in the teens and low twenties during the coldest month, January, demand heavy emphasis on cold weather starting procedures. Heaters are a necessity in every fighting vehicle. Serviceable maintenance tents and Herman Nelson heaters can materially affect vehicle availability, especially in semi-static situations. Antifreeze for water-cooled systems is at a premium. Periodical starting of vehicles is important when temperatures remain below freezing for more than compensating-idler whe’ he cause water and sand ge ?st despite frequent whr he changes. For the same r( :ht spindles on road-wheel LX- comnensatinp-idler w 24 hours. A rule of thumb which proved satisfactory is to run tank engines at 1,200 RPM for 90 continuous minutes during every 24-hour period. This allowed adequate battery charging. If a tank has been parked in mud or moved through mud prior to a freeze, the tank should be moved a few feet back-and-forth frequently to prevent the freezing of the track to the ground or of the mud in the suspension system. Support rollers, in particular, freeze up due to mud and will not rotate. A sudden hard freeze can immobilize a tank unit for hours if these types of precautions are not taken.

The very rough, rocky conditions in the stream beds tear up tank track a t extraordinary rates. A track lasting more than 700 miles is rare in Korea. Frequent fording and travel in stream beds results in frequent bum-up of road-wheel and el hubs, be-t into them !el grease easons, the arms and -1

- -u heel arms burn up and require replacement arms. When the paddies are trafficable, tank suspensions take a beating climbing over dikes which are typically located every 50 feet and are from 6 inches to 4 feet high. Serviceable shock absorbers, especially in the front and rear, are important in preserving the life of the suspension system. Torsion bars still break often and need replacement.

Conclusion Many of the ideas presented here in a Korean framework have potential application in other areas where the Army may be called to fight. The defile problem will surface in other locales with similar topography, such as some of the mountainous country in Southwest Asia or the middle East. The “LIB problem” exists wherever we encounter lightly armed troops. In each case, we see the importance of combined arms. The tanks need infantry and infantry needs tanks (and both benefit tremendously from artillery, air, and engineer support). If assets are not available from outside the tank unit to provide these capabilities, then the tanker himself must be physically fit enough and trained to get on the ground and “hump.”

Credits

The author would like to thank the tankers of the 2d Infantry Division who provided help or encouragement for this article: Captain Doug Zanders, Lieutenant Colonel

E. G. Fish, Lieutenant Colonel Larry Medley, Lieutenant Colonel John Palmer, Lieutenant Colonel Tom Surles, Colonel Tim Grogan, and Colonel Ron Griffith. LIEUTENANT COLONEL

OLEH B. KOROPEY commanded the 1/72 Armor in Korea in 1982-83 and is currently an Army fellow at the Hoover Institution, Stanford University. A West Point graduate, he also holds a masters in mechanical engineering from Stanford and an MBA from Long Island University. His career includes several combat tours as a cavalry platoon leader and troop commander in Vietnam, with service as an ARVN advisor. He has had several assignments at the Army Armament R&D Center at Dover. NJ, and is due to be assigned to the staff of the ODCS-RD&A at the Pentagon.