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Korean War Part I
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Chosin Reservoir
Korea: A Study in Unpreparedness
Role of the Forward Observer and Artillery

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Korean War Part I
Korean War Part II
Role of the Forward Observer and Artillery

Anthony Sobieski Books

FIRE MISSION! The Story of the 213th Field Artillery Battalion in Korea

Fire for Effect!: Artillery Forward Observers in Korea

A Hill Called White Horse: A Korean War story

The Role of the Forward Observer and Artillery during the Korean War
By Anthony J. Sobieski

To understand the role and importance that the artillery Forward Observer played during the Korean War, you must first understand a few basic facts and figures about the overall strategy and use of artillery during the war. With its rolling hills and valleys, high-peaked mountains, large irrigated farming areas, brutal winters and boiling summers, Korea presented all the worst for the U.S. to deal with in the United Nations' first effort dealing with the attempted expansion of communism. And, after it was all said and done, even after fifty-plus years of analyzing the conflict, Korea was, is, and will forever be known as 'The Artillery War'. Much has been written over the years about the infantry and Marines who served there, and of the battles they fought. No one is suggesting or attempting to take any credit away from their accomplishments, because when it comes down to it, the foot soldier was the one who re-took and defended what is now the country of the Republic of Korea, commonly referred to as South Korea. Many a book and article has documented their valiant efforts, but too many times, the role of artillery in these battles, skirmishes, and trying times is summed up in a few sentences. 'Artillery was called in', 'artillery was used' and 'overwhelming artillery thwarted the attack' are the most common phrases that are used in a large majority of books. These are very easy and simplistic statements which have become over-used and commonplace when talking about 'artillery' and 'The Korean War'. Unfortunately they simply do not tell the real story of what 'artillery was called in' meant, and who, what, when, and how it happened. Infantrymen simply did not snap their fingers and artillery shells suddenly appeared and blew up the enemy. Reality was, there were artillerymen loading and firing the guns, handling the communications, tracking the enemy, serving with the infantry, and sometimes giving their lives for their service.

At one time or another, over sixty different United States artillery battalions served on the Korean Peninsula. Regular Army, Marine Corps, Reserve, and National Guard battalions all played a part and served with distinction. Republic of Korea (South Korea), or ROK, artillery battalions and also a few United Nation artillery battalions also were extensively employed. Additionally, naval vessels - from destroyers to cruisers to battleships - added their heavy 'punch' of 5-inch up to 16-inch might to the mix of available firepower at the fingertips of the Forward Observer and his team in their bunker or foxhole. All this might was concentrated on a small peninsula land mass no bigger than the state of Wyoming and eventually more concentrated into a jagged uneven 155-mile front line called the 'Main Line of Resistance'. The eventual intent of the U.S. 8th Army, who had overall responsibility for the combatant zone, was to have a breakdown of artillery units roughly divided evenly between the three U.S. Corps, I, IX, and X, and the ROK I and II Corps. By 1953, there were seventeen infantry divisions across the front (ten ROK, six U.S., and one combined UN), with two divisions in reserve (two U.S.). All of the U.S. divisions were assigned four artillery battalions each, usually consisting of three 105mm units for direct support of each regiment, and a 155mm unit for heavier general divisional support. Also, four of the U.S. divisions had an additional 155mm artillery battalion attached to their chain of command, and there were two U.S. Regimental Combat Teams (RCT) with one 105mm artillery battalion each. The ROK Army artillery was a less sizable force, with seven Field Artillery 'Groups', each with two battalions assigned, and eight independent battalions for a total force of twenty-two battalions, which roughly worked out to two artillery battalions per ROK division. Outside of this divisional firepower, were the U.S. Corps artillery battalions, which were for general support of each Corps front and were readily moved if needed to support whatever combat actions were or would be about to take place. Each U.S. Corps had six artillery battalions assigned, usually consisting of a 105mm self-propelled (SP), four 155mm (some being SP), an 8-inch howitzer battalion, and additionally a artillery 'observation' battalion that did not have any howitzers, but tracked enemy artillery by various means including radar and 'flash and sound' observation posts, and then would proceed to call for fire on them. Late in the war, two units were converted to handle the 240mm howitzer, and these battalions were also added to IX and X Corps.

When the sheer numbers are looked at, some eighty-two plus artillery battalions, with roughly 400-plus men in each battalion (32,800 men total), five-hundred and twenty-two (522) 155mm howitzers, eight-hundred and ten (810) 105mm howitzers, thirty-six (36) 8-inch and twelve (12) 240mm howitzers, were utilized in Korea by 1953. All for a 155-mile front…simply incredible. Who dared to think that artillery was anything other than “The King of Battle” in Korea?!"

The Korean War, and artillery, was before the time of computers and satellites and high speed electronics. Today, the U.S. military is researching mobile artillery mechanisms that can plan, calculate, load, and fire ten rounds of 155mm ammunition in less than one minute at a target ten miles away with deadly accuracy, all with a crew of two, done simply by pushing a few buttons. During the Korean War, all of this was done by the human brain and physical strength. Each artillery battalion was divided up into five 'batteries', three 'firing' batteries, which actually had the howitzers and fired them.  There were six guns per battery for the 105mm and 155mm, four per battery with the 8-inchers, and two per battery with the 240mm. As the size of the weapon went up, so did the manpower required to fire it. There also were a 'service' battery, and a 'headquarters' battery. The service battery consisted of troops who made sure the battalion had everything it needed to fight a war with, from the artillery shells to the food rations, and the headquarters battery was just that, the headquarters section that ran the battalion. Sometimes these batteries served next to each other, but many times the batteries were separated by miles. Each battery operated a Fire Direction Center, or FDC, which was in direct communication with each howitzer section and with any Forward Observer team that they might have on the front lines. The FDC was the brains behind the brawn. Each battery's FDC was linked into the battalion FDC, which had overall control of the combat situation for the unit, and directed the battalion where it was needed the most. The Battalion Commander ran his unit through the FDC, and the Aerial Observers and the Forward Observer teams worked with both the battery and the battalion FDC's. Each FDC was manned by approximately eight men and two or three officers. Tracking the tactical situation was the life blood of the artillery battalion, and the effectiveness of the Forward Observers was directly related to the ability of the FDC to do its job well. Connecting the FDC to the individual howitzer sections, Observation Posts, and other FDC's with the other batteries were the wire section crews, using thousands of yards of phone lines to get the job done, sometimes even navigating enemy held ground to do their jobs.

Early on in Korea, it was clear that there was need for the services of someone who knew and understood the use of and employment of artillery in a fluid tactical situation. Later in the war, this expertise changed to a requirement of knowing the battlefield on intimate terms, to be ready to call fire missions on multiple actions and areas at the same time. This stemmed down from 8th Army, to the three U.S. Corps and two ROK Corps, to the divisions, regiments, battalions, companies, and individual leaders of patrols and small units throughout the front lines of Korea. The Korean War had both the outright brutality of fighting that WWII had in the Pacific, while drawling from the battlefields of Europe in it's etiquette on fighting. The brutality of the Pacific war, short battles of pure intensity, there was no falling back and regrouping, thousands of men, trained to slaughter their enemy, collocated on a small area of land. And then the war in Europe, with its huge armies thrusting and counter thrusting, moving over large areas of land, sometimes encompassing an entire country in a particular battle. In the beginning stages of the war from 1950 to 1951, movement of artillery in Korea was very similar to that of WWII, firing and movement, firing and movement. The mobility of artillery units was invaluable to the successes of the infantry and movements of the UN forces in general. By the beginning of 1952, when the war entered what is generally considered the 'stalemate' phase (although there are plenty of combat veterans from that time that would strongly disagree with that statement) and on into 1953, the Korean front began to resemble the trench warfare of WWI, with shells raining down on both sides of the front lines (hence the term that WWI veterans had 'shell-shock').

Through all of this, all artillery units used some form of artillery spotters, or Forward Observers. These ranged from FO's that served with the infantry units directly, sometimes never even knowing or seeing anyone in their firing unit for months, to FO's who were positioned in bunkers (either on or in front of the MLR) to Aerial Observers flying in an un-armed, un-protected scout plane. Also, many an infantrymen doubled as FO's in their duties when artillery battalion FO's were killed, wounded or not available. The U.S. Navy also had it's version of a Forward Observer. Naval Fire Control Officers and Liaison Officers who worked on the front lines were utilized as far inland as the guns of a particular ship could fire, and also acted as just that, liaisons for the artillery battalions and units to use the firepower of the Navy. For direct support artillery units, established OP's were not generally used, the FO parties serving directly with the assigned infantry unit they were supporting. These OP's were fluid according to the situation. Each infantry division maintained a number of divisional Observation Posts, which tended to be located and numbered across the front from 'one' to whatever number of OP's were required by Divisional Artillery (DIVARTY) or by the battalions or tactical situation, and were for the heavier divisional artillery units in general support. Corps artillery units used their own OP's which they established in their support roles of divisional artillery. These OP's were not numbered with the divisional artillery OP's and, depending on what units they were supporting, they were frequently located with UN or ROK forces. These OP's also sometimes overlapped divisional artillery OP's in their respective Corps area. Aerial Observers have a long history going back to WWI of pilots and ground troops or artillery working together to suppress the enemy. In Korea, artillery units used 'spotters', Air Observers who were flown over the battlefield by brave pilots usually in a small single engine airplane called an L-19. They were no more than flying targets, and had provided little protection and had no armament, except flares they would sometimes use to mark targets. These crewmen were U.S. Army personnel attached to the artillery units, and they sometimes rarely even knew the men of the firing batteries, flying out of airstrips miles from their units.

In the beginning, the Korean War was fought with antiquated equipment, mostly 'leftover' items from WWII. Not many improvements were added to the US Army from 1945 to 1950. The attention was on demobilization, return to civilian life, down sizing, crating up, and putting away in storage the items of war. The US participation in WWII, the last 'good war' left a distinctive taste in the mouths of those who fought it and suffered from it. No one wanted that kind sacrifice, but it was done, hence the term 'The Greatest Generation'. When the fighting in Korea splashed across the headlines of American newspapers, most said 'Where?' The fact that our forces were going into combat again caught some by surprise, but the thought process was that we had the best army in the world and that we would take care of business. The U.S. military became woefully depleted by 1950, not just with men, but with supplies and equipment. The service members who were on duty, and those that were called up reservists and National Guardsmen, certainly were the best. But times had started to change, and their equipment wasn't ready for it. Not until later in the war did our fighting men see improvements, such as 'Mickey Mouse' boots, Flak vests, and bazookas that could knock out a tank. These new assets did not make the fighting any easier on our troops, but it gave them the advantage of preparedness. U.S. artillery was no different. Loading, aiming, and firing artillery had not changed much, and the weapons not at all, since WWII. Most if not all artillery shells were of WWII vintage as well. Korea was a very different type of war indeed. By 1953, trench warfare reminiscent of WWI was the standard, but the use of more accurate artillery, with better knowledge in fire direction planning, shell trajectories, types of shells, and overall destructive power were incredible. Not before or since Korea can it be said that artillery ruled the battlefield. It truly was 'The Artillery War', and one of the major factors in making all of this possible was the men and teams who performed the role of artillery Forward Observer.

For the men assigned to Forward Observer duty, this meant being literally on the front lines, close enough to see and observe enemy actions, for the purpose of giving fire support when ever and where ever needed. These men regularly became the focus of unwanted attention by the enemy, sometimes even being caught right in the middle of a raging firefight. Artillery battalion Observation Posts (OP's) were almost daily shelled by enemy artillery and mortar fire, and at times took small arms fire. Sometimes a simple entry in a unit's daily morning reports, such as a statement like 'OP #2 received rounds' was a very polite way of saying that that position was being targeted and fired on. The communists realized that knocking out these OP's meant eliminating some of the allies' ability to fire at them. Also, the need to have the FO team either right with the infantry or in close proximity to them endangered their lives even more. The fact that so many FO's have called fire onto their own positions brings to light a startling realization of what Winston Churchill said 'Uncommon valor was a common virtue'. These men KNEW what they were doing. They had a choice: be killed or captured, or fight it out and possibly lose their life and the lives of their FO team also. This was not a decision made lightly. There are numerous documented cases where the FO called artillery fire onto his own position because they were being overrun. What FO does not readily know or understand what they are asking their firing battery to do? And at the same time, what FDC and firing battery does not understand what they are hearing on the radio or field phone? A man that they more than likely knew, yelling to them to shoot high explosives at them, knowing that this might be the last time their voice is ever heard on this earth? The 'cause and effect' rule is in full swing, and they, the FO and his team, know it. Fire a 37 or 100 pound shell filled with high explosive at a specific coordinate and destroy (kill) whatever is at that coordinate.

The following information was compiled with the grateful assistance of 1st Lt Joseph Reynolds, who served as an artillery Forward Observer with the 936th Field Artillery Battalion in 1952. This provides an excellent overview of what goes through an FO's mind, and what has to be thought about and calculated to call a fire mission on the enemy. Most, if not all, of the following happens in minutes and seconds, where inaction and delays could cost American or UN lives. As with any career field, there is 'technical jargon' that must be understood and applied by those that work in that career field. For an artillery battalion FO, the following would apply 'in a nutshell': The Army prescribes a set method of making fire request information to the Fire Direction Center in order to minimize confusion and to facilitate rapid fire as much as possible. These commands are designed to be logical and in an easily used manner. Fire requests must contain certain information to enable the Fire Direction Center to compute the firing data. In divisional artillery battalions, each firing battery usually used the standard method of having two Forward Observers and crew on the Main Line of Resistance (MLR). The use of two Observation Posts usually covered the complete arch of trajectory of the firing battery. In Corps support units, any number of OP's was used to support the tactical situation, sometimes one, sometimes three OP's per battalion. The 'tools of the trade', the binoculars and BC scopes, included a graduated reticule that enabled the Observer to measure lateral distances with some degree of accuracy. The value of the 'mill method' of measuring angles was effective in that with the mill method, there was an arc of 1 unit in 1,000. When an Observer, with the use of the reticule, measures a lateral distance of 20 mills and the estimated range to the target is 3,000 yards, then the lateral adjustment would be 60 yards. Vertical graduations are 5 mills each, and vertical scale would be used for such positions as machine gun emplacements. Horizontal graduations are 10 mills each. Military maps, when available, show contour lines that enable the Observer to better identify the target location coordinates. In layman's terms, the BC scope was to a Forward Observer as an M-1 rifle was to an infantryman.

Some Fire Request types are as follows:

• Identification of the Observer. The fire direction center must know who is requesting fire. This can be a code name or any other method acceptable to the commander.
• Azimuth. Direction which the observer is looking at the target. This is very important especially if the observer is at an angle to the direction of fire from the guns.
• Target location. This location can be in many different forms. It can be identified as coordinates, range and azimuth from a known location, and range and direction from the observer to the target, or shift from a previously fired upon target and others. Circumstances determine what method the observer will use in identifying the location of the target.
• Substance of the target. The fire request should identify the type of target for the fire direction to order the proper shell and fuse type.

These are examples of fire requests made by Forward Observers. They will vary in content but notice that they generally follow a set procedure in transmission. Not all fire missions were done in this format, taking into account the expediency of the mission being called. If a position or OP were about to be overrun, or were already overrun, as was the case numerous times in Korea when faced with the Chinese 'human wave' attack style, some missions tended to be called in somewhat 'colorful' ways. As 1st Lt Joe Adams (213th Field Artillery Battalion) recollected when talking about the Battle of White Horse Mountain, Hill 395, in October 1952, he remembers when the Chinese stormed over his OP and surrounding positions, his call to the FDC went something like "The Chinese are all over the fucking place start shooting at my bunker!". Sometimes units set up a 'Final Protective Line' where pre-registered final protective fire coordinates would be given so as to, again, deal with an assaulting force that was about to overrun a position. These were at times referred to as 'Flash Fires' such as were used during the defense of Pork Chop Hill in April of 1953, when the order was given by 2nd Lt Richard Jaffe (57th Field Artillery Battalion) "Give me Flash Pork Chop!", which in essence meant for all available artillery to fire directly onto the hill with variable time (VT) fuse shells.


Observer is from Able Battery, and is their second Observer. Target is small group of enemy setting up a mortar. The target is in an area easily identified on a map and the coordinates of the target can be determined with some degree of accuracy but adjustment will be necessary.

Request #1: "Fox Oboe Able No. 2, Fire Mission! Azimuth 2300, coordinates 236-421, enemy mortar digging in. Will adjust!" The Fire Direction Center transmits confirmation to the firing battery and will repeat the information, adding such information as "Battery one round in effect". This means the eventual fire for effect will be six rounds, one round per tube.

The initial fire would be two rounds fired simultaneously which the observer would adjust from the center of the burst of the two rounds. The classic adjustment would be a left or right adjustment to get the rounds on line with his line of sight and the target. From there he would give add or drop with the first adjustment of 400 yards; then 200 yards followed by 100 yards and then an add or drop of 50 yards, then the command "Fire for effect" is given. This method was generally used but after becoming familiar with the target area a Forward Observer would quite often make adjustments for line of sight along with the initial add or drop and many times the initial rounds would be within 100 to 200 yards of the target.


Observer is from Baker Battery and is the Observer number 1. Target is near Check Point 210. The target is enemy squad in open.

Request #2: "Fox Oboe Baker No. 1, Fire Mission! Azimuth 3200, from Check Point #210, right 300 add 500, Enemy squad in open, will adjust!" The Fire Direction Center transmits confirmation adding such information as "Battery one round fuse VT in effect".


Observer is from Charlie Battery and is the Observer number 1. Target is 1000 yards from the observer. The target is an enemy bunker.

Request #3: "Fox Oboe Charley No. 1 Fire Mission! Azimuth 0400, Coordinates 234-146, Range 1500, enemy bunker, request precision fire, will adjust!" Fire direction transmits confirmation and adds such information as "Precision fire, fuse delay in effect".

The battery will fire one round on adjustment and then when fire for effect is called for, the guns will fire fuse delay and a succession of rounds will be fired with the Observer reporting the landing point of each round in regards to the target. Fire Direction Center will average 'overs', 'shorts', 'lefts', and 'rights' to make corrections until the target is destroyed.


Observer is from Charlie Battery and is the Observer number 2. Enemy is in attack on a front of some 500 yards. The Observer sends estimated target center and calls for additional fire.

Request #4: "Fox Oboe Charley No. 2, Azimuth 2800, coordinates 354-456. Spread sheaf 500 yards, enemy infantry in attack. Request all available fire!"

Fire direction responds by repeating the request to the Observer and adds: "One battalion in initial fire, requesting support from Corps. Report observation!"

Artillery Forward Observers surely did not 'win the war'. But the power and responsibility that was placed into a twenty-two or twenty-three year-old lieutenant's hands was amazing to say the least. One call on a field radio or EE8 field phone could bring in more destructive power than an entire company (and sometimes battalion) of infantry. For those FO's that had the distinction of calling in a DIVARTY or Corps 'shoot' where all available artillery within reach of the target was at their disposal, the terms most used to describe the experience was 'awesome' and 'unbelievable' when the destructive power is witnessed. Many a Chinese and North Korean soldier lost their lives, and many U.S., ROK, and UN lives were saved, by a man who did not even pull a trigger. He simply and professionally said 'Fire for Effect!'


Fire For Effect!  Artillery Forward Observers in Korea By Anthony J. Sobieski ISBN: 1-4208-3836-9

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© 2024 Anthony J. Sobieski

About the author:
Mark Bennett is an Army Major and OH-58D Kiowa Warrior pilot. He attended the United States Military Academy for his undergraduate studies and completed a master’s degree in military history through Norwich University. Mark has lived around the globe, most recently living in France, but still calls North Carolina home. He is married to a former Army Officer and is the proud father of one daughter. He is the son and grandson of United States Marines.

Written by Anthony J. Sobieski. If you have questions or comments on this article, please contact Anthony J. Sobieski at:

About the author:
Anthony Sobieski is a Department of Defense employee and retired U.S. Air Force reservist. He is a recognized Korean War historian and author, having published three books on the subject; FIRE MISSION! (2003), FIRE FOR EFFECT! (2005), and A Hill Called White Horse (2009).

* Views expressed by contributors are their own and do not necessarily represent those of
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