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Posted on Feb 10, 2010 in Tactics101, War College

Tactics 101 046: Relief in Place

By Rick Baillergeon and John Sutherland

Our past article began our mini-series on tactical enabling operations. In it, we discussed the passage of lines. As a review, our key takeaways were: 1) The execution of a passage of lines is much more difficult on the ground that it is on paper! 2) A successful forward passage of lines can set the conditions for a subsequent successful attack. 3) A successful rearward passage of lines can be instrumental in preserving combat forces for later use. 4) Coordination is critical in a passage of lines. With time available, the passing and stationary must meet and iron out the details. 5) A passage of lines can be an extremely chaotic operation. Effective communication between those involved can alleviate some of the chaos.


In this month’s article, we will continue focusing on tactical enabling operations. Our discussion in this article is on the relief in place. We will focus on answering the following questions: 1) What is a relief in place? 2) What is the purpose of a relief in place? 3) What are the considerations in planning a relief in place? 4) What are the considerations in preparing a relief in place? 5) What are the considerations in executing a relief in place? Let’s execute!



It is an operation in which one unit is replaced, on a specific piece of terrain, by another unit. This may occur as part of an offensive, defensive, or stability operation. It can be executed during all types of weather and in day or (preferably) night conditions. A relief in place is normally ordered by a higher headquarters Commander who has command and control authority over both the relieved and relieving unit.

Overlay of a Brigade Relief in Place


There are numerous reasons why you would conduct a relief in place. These include the following:

· The higher headquarters may possess a fresh, combat ready unit that it wants to get into the fight.

· A unit has taken significant losses in combat and is/or near being combat ineffective.

· A unit may have gone through some significant emotional/mental stress and needs to be pulled back away from the front.

· A unit may simply be tired physically and mentally and needs a rest.

· A unit may have been hit by a chemical or biological weapon and it has been decided they will be decontaminated in the rear area.

· A unit has been assigned a new mission. However, the terrain it currently occupies is still important tactically to the higher headquarters Commander. Consequently, it must be occupied by another unit.

· The higher headquarters Commander may conduct a relief in place as part of a deception operation. Obviously, this is resource intensive, but it can pay dividends. The act of the relief in place may cause the enemy Commander to react in a way that may put him at a disadvantage.

· The higher headquarters Commander may initiate a relief in place so the relieving unit can establish some type of security force forward in the area of operations.


Planning a relief in place is a significant endeavor. There are many moving pieces and the tactical situation is certainly dynamic. Throw in the probability that planning may take place in the middle of combat and you have a true test on your hands.

To assist in meeting this challenge, it is imperative a unit conducts quality planning. As with a passage of lines, the variable in planning is time available. In some instances, there will be sufficient planning time available. This is especially true when you are conducting a somewhat ‘preplanned’ relief in place. However, there are many times when planning time is at a premium. In either case, you must make the most of every minute.

With that said, the key factor in determining available planning time is what specific type of relief in place you will conduct. In regards to types, we do not get real creative. We categorize them as either deliberate or hasty. Like I said, not real imaginative, but it meets the needs.

As the name suggests, a deliberate relief in place is thought out in advance. Thus, there should be more planning and preparation time for units to utilize. Within a deliberate relief in place, you are likely to find additional detail and an operation that is more synchronized and orchestrated. With extra time, the Commander and his staff should work out all the what-ifs and develop corresponding contingencies.

In contrast, the hasty relief in place is decided with little notice. It is normally conducted in direct response to the tactical situation. In the majority of cases, the situation is probably not good for the home team. Thus, a quick decision has been made to conduct a relief in place. The repercussions are a dramatically shortened planning and preparation cycle.

Below we will discuss the key areas that must addressed in planning (no matter what time is available) to set the conditions for the success during execution.

Relief in Place Techniques

During planning, the first thing that should be decided is what relief in place technique will be utilized. A Commander will generally choose from three techniques. These are:

· Relieving Units One at a Time

· Relieving Units Simultaneously

· Relief by Occupying In-Depth and Adjacent Positions

Let’s discuss each below.

Relieving Units One at a Time

A Commander will generally decide on this technique when the following conditions are evident: 1) The enemy may have visibility of the terrain occupied by the relieved unit. 2) There are limited routes for the relieved and relieving units to utilize during the execution of the relief. Many times there is only one route in and out of the terrain.

The sequence of this technique is as follows: First, command and control elements of each force co-locate to facilitate execution. Second, (we will use a battalion replacing a similar type battalion in this example) the first relieving company maneuvers forward to an assembly area near the company it will relief. Third, once the relieving company occupies its’ assembly area, the relieved company will move out of its’ positions and maneuver to its’ own assembly area in the rear. Fourth, the relieving company occupies the positions vacated by the relieved company. Fifth, once the relieved and relieving companies are in position, the same sequence begins with the next two companies (the relieved and relieving). The battalions will continue this sequence until the relief is complete.

As can be surmised, the execution of this technique can be extremely time consuming. This is especially true if units can only utilize one true route to maneuver on. If confined to one route; forces are susceptible to artillery and have little terrain to react to any enemy action.

Relieving Units Simultaneously

A Commander will normally choose this technique when the following conditions apply: 1) A quick relief is required. 2) Enemy detection of the execution of relief is not likely. 3) The terrain in which the relief is to be conducted affords multiple covered and concealed routes.

As the title implies, within this technique all units within the location are relieved at the same time. The sequence of this relief normally occurs as follows: First, command elements from the relieved and relieving units co- locate to facilitate planning and preparation and then to set the conditions for execution. Second, the relieving units maneuver towards the relieved units positions. Third, as the relieving units maneuver; the relieved units begin to maneuver out of their positions. Fourth, as the relieved unit leaves their positions; the relieving unit occupies them. Fifth, the relieved unit maneuvers rearward to occupy an assembly area.

Clearly, there is some risk in conducting this technique. With all the moving pieces there is little chance in concealing the operation from the enemy (if he has eyes on the area). Of course, if he has the capability, he can have a field day with well-placed fires (especially indirect). Thus, as mentioned before you only want to conduct this technique if you have good reason to believe the enemy can not detect the execution.

Relief by Occupying In-Depth and Adjacent Positions

A Commander will utilize this technique when the tactical situation is as follows: 1) The relieved unit may have been contaminated by chemical or biological weapons. 2) The relieved and relieving units are dissimilar types of units. For example, the relieved unit is a mechanized/armor unit while the relieving unit is a light infantry unit. Obviously, the terrain requirements are entirely different between these organizations. 3) There is sufficient terrain for both the relieved and relieving units to occupy during the execution. 4) The terrain should allow the relieving unit to use basically the same direct fire control measures (Engagement areas, target reference points, etc…) as the relieved unit.

The sequence of this technique is: First, command and control elements from both units co-locate to facilitate execution. Second, the relieving force maneuvers to their positions in vicinity of the relieved unit. This maneuver may be conducted simultaneously or sequentially. Third, once the relieving force is in place, the relieved unit will depart their positions to the rear. Again, their maneuver may be done simultaneously or sequentially.

Within the technique, terrain is certainly the key. There must first be enough of it, to support two units at a time (for a period of time). Second, it must be a piece of terrain that is defensible by different types of units. Obviously, what is good for a tank may not be good for a machine-gun.

Control Measures

In any operation, well-planned and understood control measures can greatly assist in mission accomplishment. This is without a doubt the case in a relief in place. Control measures in the relief have many benefits. They include: 1) They provide direction in an environment and situation normally needing direction. 2) With many moving pieces, they assist in preventing fratricide. 3) They are the blueprint for execution and aid in flexibility.

Below you will find a basic set of graphics with its associated control measures. The graphics are an example of what may be utilized for one infantry company relieving another infantry company. Following the depiction, we will highlight some of the more commonly used control measures.

Assembly Areas (AAs) – Within a relief, AAs are generally used as temporary holding areas. For the relieving unit, they may occupy an assembly area until the relieved unit has departed their position. Vice versa, the relieved unit may occupy an assembly area after they depart their positions to prepare for their maneuver rearward.

Routes (RTE) – It is imperative routes are designated for all units to maneuver on. These routes assist in reducing confusion, preventing fratricide, and aid in developing momentum for the operation. Designated routes also aids in ensuring vehicles do not venture onto terrain they shouldn’t (minefields, obstacles, etc…).

Start Points (SP) and Release Points (RP) – Related to all routes is the necessity for assigning the exact start point and release point for each route. These control measures support command and control during the operation.

Contact Points – One of the most important control measures within a relief is the contact point. As we have defined in earlier articles, this is where two units physically meet to conduct coordination. Within the relief, this must occur as quickly as possible. The contact point is determined by either the higher headquarters of the relieved unit. Based on the mission and terrain, there may be more than one contact point required.

Defensive Control Measures – Because a relief in place is normally associated with a defense; the typical control measures will usually be utilized. Since the relieving unit may very well fall into the defense of the relieved unit; there must be defined battle positions, engagement areas, target reference points etc….

Command Post Locations – In an operation where command and control is critical; it is imperative command post locations are determined. In particular you must specify where the command posts of each unit will co-locate.


We have addressed two key areas that must be well thought out in planning – the type of relief and control measures. Obviously, there is far more that must be analyzed and determined. Below we will highlight some of the more critical aspects of planning utilizing the battlefield operating systems:


· One of the first actions that should be executed in planning is to conduct a reconnaissance of the ground for the relief. There are some specific areas that should must be looked at/analyzed during the recon. These include: all pertinent terrain, defensive positions, key weapons systems positions, potential relief routes, potential assembly areas, and logistical nodes. This recon sets the conditions for you to understand what can be done and what can not. It also assists you in drawing up your initial control measures. .

· During planning, the relieved unit should refine all their intelligence products (situation templates, courses of action, etc.) and pass them to the relieving unit. This enables them to progress in their own planning.

· It is vital that security be emphasized (emphatically) during planning. This is achieved through the following: 1) Conducting the relief in limited visibility ( night). 2) Maintaining normal operations during planning and preparation (do not tip your hand). 3) In regards to communication, the relieving unit should not use their radio nets until the relief is finished. (If they do, the increased radio traffic in the area could again tip your hand). 4) When conducting reconnaissance of the area, the relieving unit should send the bare minimum of vehicles and troops. (If they send extended numbers, this once again could tip your hand).


· Contingency plans must be planned to react to enemy attempts to disrupt the relief in place.

· The plan for the relief should facilitate the follow-on missions of both the relieving and relieved units.

· Ensure you have flexibility in your plan. This includes planning alternate routes, assembly areas, etc….

Fire support

· It is critical that early in the planning the technique for relieving the fire support units be determined. You cannot mess this up. Because of the nature of the mission, fire support may be the only asset you have to keep you out of trouble. Thus, you must have responsive fire support at all times.

· The best technique to utilize is for the relieving unit ‘guns’ to stay in place until most the combat units have been relieved. Once this is achieved, then the relieving fire support unit can replace the relieved unit.

· To keep responsive fires at all times, you will want to relieve the relieved unit in small increments. This could be by section or even firing position. However, the tactical situation may dictate relieving by platoon.

· During planning and preparation, the relieved unit should continue their normal activities. For example, if they have been firing harassing fires (at a certain amount per time period) then this pattern should continue.

. Mobility, Counter-Mobility, Survivability

· During planning, one of the first actions that must occur is an exchange of the obstacle plans. Everyone must know where obstacles/minefields are located. This is especially critical if the relief is conducted at night. These locations can affect the locations of routes, assembly areas, etc….

· It is also important to have confirmation on the number of fighting positions (vehicle and individual) that the relieved unit has constructed. During planning this can assist in deciding the relief technique utilized.

Air Defense

· The relief of air defense assets is similar to fire support elements. Thus, the relief of these assets should not take place until the combat units have completed their relief.

· Besides planning for their own relief, air defense must obviously plan for coverage during the relief itself. With that said, planning should key on ensuring the routes, assembly areas, and choke points have maximum air defense coverage.

Combat Service Support

· When it comes to planning any type operation; it always seems that anything associated with logistics tends to get second billing. As we know, that is a big mistake! This is certainly true in a relief in place. Clearly, planning for the relief of your combat service support elements is just as important (or more so) as the relief of your ‘killers’.

· The overall plan for the relief should dictate that the logistical units are relieved first. The rationale is you want your relieved logistical assets to be in place in the rear once the rest of the unit falls back.

· Just as the main tactical command posts are co-located; you will want to plan to co-locate your logistical command posts to facilitate coordination.

· Based on the tactical situation, you may plan to keep some of the relieved unit’s supplies in place for the relieving unit. Examples of this could include tank main gun rounds and barrier material. Obviously, these are items requiring significant man hours and transportation to move rearward. If they are needed by the relieving unit, you are saving these valuable resources.

· If the terrain obliges, you may want to plan for separate routes for logistical vehicles to maneuver on.

Command and Control

· As soon as you determine a relief in place is necessary; you should issue a Warning Order (WARNORD) to the subordinate units. The WARNORD should include details such as: time of the relief, relieving and relieved units, sequence of key events, future missions of the forces, route priorities, any restrictions on advance parties, any extraordinary security measures, and the time and place for issuing the complete order. These details enable units to begin planning.

· As we have mentioned (and will continue to do so) coordination between the relieved and relieving units is imperative. With this the case, you may want to plan on keeping some liaison personnel from the relieved unit with the relieving unit after the relief is complete. This allows for continuity at a critical time.

· During planning, one of the most important decisions to be made is when command will pass from the relieved unit to the relieving unit. Until command passes, all relieving forces come under the command and control of the relieved unit Commander.

· Generally, command passes when two conditions are met. First, the relieved unit’s combat units have been relieved. Second, the relieving unit has established quality communications within the area of operations. When command passes, any relieved units fall under the relieving unit Commander.

Indirect Fire


As highlighted earlier, time is at a premium during a relief in place. Just as there is never enough time in planning a relief; there is little time available in preparation of the relief. Clearly, every minute must be utilized to its fullest. Below we will offer some actions during preparation that if executed can greatly assist in overall mission success

· The most important action that must take place during prep is coordination between the leadership and staff of the relieved and relieving units. There are many issues that must be discussed and hopefully worked out. Obviously, the optimal way to conduct this coordination is face to face with a link-up of the command posts. However, co-locating these command posts takes time and time may not be available. If that is the case, there are other options. These include: 1) linking-up a few vehicles and key individuals from each unit to conduct coordination. 2) If physical coordination is not feasible; then it may be possible to take advantage of the technology available. Video-teleconferences and other communication devices can be a tremendous benefit.

· There are many key things that must be nailed down in coordination. Below are some of the more critical:

· Exchange of intelligence (focusing on the enemy and the terrain).

· Reconnaissance.

· Exchange of tactical plans (for each unit) and sector sketches of the defensive area.

· Sequence and timing for each subunit’s relief.

· Time or circumstance when command passes.

· The use of guides and liaison personnel.

· Security measures.

· Fire support.

· Transfer and exchange of equipment, supplies, ammunition, and minefields.

· Control measures.

· Exchange of frequencies, call signs, challenge and passwords, and recognition signals.

· During preparation, the process of gathering and analyzing intelligence must continue. The environment is continually changing and you must understand when it has changed and what effect that has on your operation.

· It is important units attempt to conduct normal activities as much as possible during preparation. Just as you ware watching him; he is watching you. Do not tip your hand too soon.

· Get out your air defense assets as quickly as possible during preparation. An area that will soon be occupied by two units is a lucrative target for enemy air.

· Unfortunately, the possibility to conduct a thorough rehearsal is fairly slim. However, this should not discourage units to conduct some lesser form of a rehearsal. As we have discussed in other articles, rehearsals can take all shapes. They may occur on the hood of a vehicle or via the radio. Whatever the case, a good commander will dictate a rehearsal is conducted and a good staff will ensure it occurs.

· Discipline is vital during preparation. Units must exhibit excellent noise and light discipline. Carelessness can once again tip your hand.

· Both units should take any available time and recon the routes that will be used during the relief. You should conduct these route recons in various environments (day, night, wearing protective gear, etc…).

· Based on the types of units involved in the relief, it may necessary for the construction of fighting positions. For example, let’s say a light infantry unit must relieve an armor unit. Not the best of propositions, but entirely possible. If this is the case, then the armor unit may need to begin preparing individual fighting positions for the light infantry unit. Armor Soldiers may not be happy about this task. However, in the grand scheme of things this action will save precious time and could very well save the lives of their fellow Soldiers.

· During preparation, all units involved can surely become overwhelmed with the number of tasks that must be completed to execute the relief. Units must be careful not to focus all attention on the relief and lose sight that there is an enemy out there. The higher headquarters of the units conducting the relief can assist by designating assets against the enemy.

· The higher headquarters can also assist in buying time and even deceiving the enemy by conducting a demonstration or feint near the location of the relief. This action can shift the enemy’s attention away from the relief.

· During preparation, the relieving commander should review the defensive plan of the relieved commander. He must determine how his assets and his strengths and weaknesses will integrate into the plan. Again, because time is at short supply; tweaks are the rule and not wholesale changes.

· As in any operation, prep time is leader’s time. Good leaders must be circulating around the battlefield to ensure tasks are being executed to high standards.

· The staff is also extremely busy during preparation. They must monitor the status of preparation. If things are going slow in one area; it may be necessary to shift assets to assist. If assets are needed and not possessed; the staff must quickly request these assets from their higher headquarters.


The planning and prep are complete now it is time to execute the relief. Below we have provided some keys to success in terms of executing the relief in place.

· Reconnaissance must be conducted throughout the relief. A good enemy is constantly using its’ own recon to determine what you are doing. You must do the same.

· Mass is good in most actions associated with warfare. However, massed forces in a relief in place normally leads to massive amounts of artillery placed on the masses.

· There is a significant possibility that there will be enemy contact during execution of the relief. Thus, it is critical to know who is in charge at all times during the execution. When command changes from the relieved unit to the relieving unit; it must be understood by everyone.

· During the execution, both the relieving and relieved units are prepared to fire. The relieved unit artillery is reinforced by the relieving unit.

· There must be a handover of all obstacles constructed by the relieved unit to the relieving unit. It is vital all elements know where lanes are located within obstacles. No discovery learning here!

· Once the relief is complete, the relieving unit must ensure all lanes are closed.

· During the execution, it is important all maneuvering vehicles utilize the terrain to its utmost. This is the best way to keep the enemy guessing as to what is happening on the ground.

· The relieved commander must ensure his elements are extremely disciplined during their maneuver rearward. In many instances, the relieved unit has been through significant combat and may be anxious to depart the area. Human nature can very well influence Soldiers to get out of the area of operations as quickly as possible. This action can lead to a chaotic environment and can greatly hinder the ability to successfully complete the relief.

· Indiscriminate use of smoke (in hopes of deceiving the enemy or masking the relief) can hurt the ability of friendly forces in accomplishing the relief.


As you have surmised from the above, the relief in place is a true challenge to plan, prepare, and execute. Below we have highlighted the key nuggets from the article:

· There must be flexibility built in planning and you must be flexible during execution.

· Do not tip your hand too early to the enemy. The relieved unit must try to continue to conduct normal activities during planning and preparation. If the enemy determines a relief is imminent; they will capitalize on the situation. Friendly forces are extremely vulnerable to enemy action during the relief.

· As much reconnaissance (with minimal personnel) as the relieving unit can conduct prior to the relief – the better.

· Command and control (as always) is at a premium during execution.

· Coordinate, Coordinate, Coordinate. This is facilitated by a quick link-up of command posts.

· Well-analyzed and understood control measures are a must.

· A good relief in place will set the conditions for future success for both the relieved and relieving units.

· Responsive fire support can keep and get you out of trouble.

· Do not neglect or downplay logistical planning and preparation.

· There must be an understood plan is to when command passes from the relieved to the relieving unit.


Our next article will focus on encirclement operations. As we have seen throughout military history, the ability of a force to either encircle its’ opponent or vice versa, break out of an encirclement has turned the tide on many a battle and campaign. Our discussion will key on precisely the above. We will look at encirclement on both sides – the encircler and the encirclee (not doctrinal terms!).

“There is always hazard in military movements, but we must decide between the possible loss of inaction and the risk of action”.
—General Robert E. Lee


  1. Helpful document. But cant get it in PDF format.

    • Thanks for the feedback. Simply print it to PDF instead of to a printer. That should help you.