Archive for the ‘Land Navigation’ Category

An important aspect of using a topo map is the fact that you can pin-point a location on the earth, transpose that location onto the corresponding map with fair precision and then communicate that location to others. This allows you to locate and share items such as link-up points, caches, targets, en route rally points, etc. The most efficient method is the grid reference system.

I won’t go into a detailed topo map discussion here, Max Velocity’s already done that on his site with an excellent primer. He explains how to locate a point on any 1/25,000 OR 1/50,000 topo map using the Military Grid Reference System (GMRS). If you are attending his course he has written that this is the map system he will use. He goes on to write that you can buy any USGS topo map with the GMRS grids pre-printed on your personalized map at mytopo.com. I have ordered maps from them and I highly recommend them.

For those folks who already have a stock of USGS maps that are 1/24,000 maps, have the ability to print their own maps or have compasses in 1/24,000, I will explain how simple it is to draw a grid system on your map. The following is taken directly from maptools.com:

All USGS topographic maps printed in the last 30 years or so include UTM grid tick marks, in blue, on the margin of the map. For a short time period after 1978 the USGS was printing a fine lined UTM grid on their topographic maps. They have since discontinued this practice.

Since most USGS 1:24,000 scale topographic maps do not have grid lines printed on them, you will need to draw them in by hand.

Start by finding a flat surface to work on. Use a straightedge that is long enough to draw a line across your map. Two to three feet long is a good length.

Line the straightedge up between two corresponding UTM tick marks along the neat line (the edge) of the map. Remember that UTM grid lines are not exactly North-South or East-West anywhere but in the center of a zone. This means that the grid lines will not be parallel to the neat lines.

Using a mechanical pencil or a fine pointed pen draw a line between the two tic marks. If you are using a pen, select one that has waterproof ink. In addition, you will want to use a straightedge that has the edges lifted off of the paper. This will help keep from leaving an ink smudge when you move the straightedge. High quality straight edges will often have a thin piece of cork stuck to the bottom. This helps keep the rule from slipping, and keeps the edge off of the paper. A piece of masking tape centered on the bottom of your straightedge will work also. Occasionally wipe of the edge of the straightedge to avoid any ink build up.

Gridding maps is tedious work. We all wish the USGS would go back to printing the grid on the map. But even then, we would still need to grid our existing maps. As you can see this is not the kind of thing you want to do on the hood of a truck or using a flat rock. Grid your maps before you need them in the field! In a pinch you can fold the map over on itself and use the edge of the paper as a straightedge.

A couple of items that bear repeating; the outside map margin or border is known as the “neat line” and the UTM grid tics are tiny, blue lines that extend out from the border (or neat line) on each side, top and bottom. Insure that when you draw in your lines that the UTM grid tic mark numbers match top to bottom or side to side and they are all parallel to each other. When you are finished you will have a matrix of squares filling in your map. Some of the grids along the margin might not be complete squares, until you join up adjoining map sheets with grid squares drawn on them also.

The squares you have drawn are one thousand meters across or in other words, one kilometer. Or as we said in the Army, one “click”.

Now you can use the scales on your 1/24,000 compass base to locate items up to 100 meters.

Another nifty tool I always carry in my map case is the Brooks-Range All-in-one Map Tool Pro. Google it and blow up the picture on your computer. It has every scale I’ve ever used and some I haven’t. It also has your grid reference tool for 1/24,000 maps that you just lay over your map. It also contains slope indexes along the bottom that you can lay over the contour lines on any map and it will give you the corresponding incline. It also has a compass rose in the middle surrounding the grid index. If you gut a piece of 550 cord, pierce the very center of the compass rose intersection with a needle creating a tiny hole just large enough to feed one of the 550 strands through, tie a knot on the strand on the front side of the tool, then pull the strand through the hole in the tool until the knot tightens against the front of the tool. When you are finished you can lay the tool on the map, north pointing to the top of the map, with the center knot over your present location, turn the tool to align the map tool edges or grid lines with the grid lines you have drawn on your map, then pull the strand around until it intersects your target on the map. You can then read the direction or azimuth in degrees to your target off the compass rose on your tool.  No need to draw lines on your map or to even lay your compass on the map. Now set your azimuth into your compass, keeping in mind the declination offset (unless it is built into your compass) then move out and draw fire.

DOL

DM

 

 

 

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Choosing a compass

Posted: 12/16/2014 in Land Navigation

I’ve been asked by several readers which compass I use and why I chose it. My primary compass is the Suunto MC-2, my alternate compass is a Suunto A-10 and the compass in my survival kit is a little Brunton Globe. While in the Army we were trained to use the standard military lensatic compass but, during the deployments during GWOT, some SF teams were issued a version of the Suunto MC-2 with special tritium illuminated parts that most of us found to be superior to the lensatic.

Like weapons, not all compasses are of the same caliber and no one compass excels for all uses. Some are toys, some are junk and some are overkill, so depending on the terrain you are operating in and what you are doing at the time, they can get you lost and embarrassed or worse, lost and dead. If I had to bet my life on a compass, it would be either a Suunto,  Cammenga or a Brunton.  My primary, the MC-2 is considered an advanced nav. compass and it is pretty rugged. My secondary (backup) is an orienteering compass that is quite a bit lighter, and while it won’t take the licks the MC-2 will, it will allow me to continue the mission. The little Brunton Globe is my go-to-hell compass, it will get me home and that’s about all I can ask of it. Avoid very expensive professional compasses designed for surveyors, loggers and geologists. They are usually a little bulky, heavy and you’ll cry like a baby when you lose it or break it. Also avoid the Chi-com made Silva compasses like the plague. Yes, Silvas sold in North America are made in China. The true Silva compasses are still made in Sweden but are not imported here.  I still have a Chi-com Silva Ranger someone gave to me that has the direction-of-travel arrow pointing in the wrong direction. The Suunto is made in Finland, the patron nation of orienteering, the Cammenga in Michigan and the Brunton in Wyoming. My only hands-on experience with the Bruntons, beside the little Globe, is the Army M-2 that was used by Army mortar and artillery crews and I remember it being a well-built compass. If you’ve used the virtually indestructible M-1950 military lensatic compass, you’ve probably used a Commenga. The civilian version of the M-1950 is the Commenga 3H. As far as I know, it is the only civilian compass with a tritium illumination. The use of tritium allows the compass to self-illuminate without the aid of a light that is required to charge the phosphorous in other compasses. The life of the tritium is about 10 years (true half-life of 12 years). If you feel that the lensatic compass is for you, a word of warning; there are tons of cheap Chinese knock-offs floating around. I see one or two at each land-nav class I teach. Usually, they are made of plastic, don’t have a dampened floating needle, (the needle never seems to settle down) and the parts that are supposed to be phosphorus are just green paint. Also of note; if you find a military surplus lensatic, it’s probably past the half-life of the tritium and will not illuminate properly. Check for the manufacture date on the back of the compass.

What to look for in a good compass:

The compass should have a liquid filled housing with no bubbles under the lens and a jeweled needle bearing.

The base plate should be transparent in order to view a map through, and have embossed scales relevant to the maps you will use.

The needle, orienting arrow, rotating bezel ring and orienting marks should be luminous for night use.

The bezel should have detents (or “clicks”) to hold it in place when set.

Declination scale.

There should be an attaching point for a lanyard. This is pretty important. I usually keep my compass lanyard (a piece of gutted 550 cord) tied through the button-hole in either my top left shirt pocket or lapel, or if no button-hole when wearing a combat shirt, attach it to the suspenders on the battle belt or a plate carrier attachment point.  My point is attach it to your person.  Do not tie it around your neck, that’s a no-no that might come back to haunt you during a ground combatives engagement.  Do not make the lanyard so long that it can reach the ground when you go down on one knee. Old war story; I had a buddy going through SF Selection with me, taking the land nav. exam when he fell onto a knee at night while moving through the woods. His lanyard was so long that when he fell, his knee fell onto his open compass, breaking out the lens and crushing the needle. He had no backup compass and failed the exam. Close your compass cover and stow it away when you’re not looking at it.

Additional items I look for:

A hinged cover with integral mirror.  The cover protects the compass face, base plate and mirror from damage and, of course, keeps the mirror from flashing inadvertently. The mirror is used for the more precise land nav. functions such as section/re-section. It can also be used for applying camo, signalling, shaving, and checking for ticks in those places you can’t normally check by yourself and your Ranger Buddy probably won’t help you with. When the mirror is folded out flat, it gives the user a longer straight edge for drawing lines on the map.

Multiple map scales and rules. Something  very important to consider before purchasing a compass.

Determine the scale(s) of the maps you intend to use since the scales on the compass need to match them. With the Suunto, the embossed compass scales will either be in inches (standard) with map scales of 1:24,000 and 1:62,500 for use with USGS maps printed for the United States, or for maps of virtually all other areas of the world, the compass scales required will be in centimeters and the map scales of 1:25,000 and 1:50,000. Military Grid Reference System (MGRS) maps, including those of the USA, use metric scales. I keep compasses for both type of maps.

Magnifying glass. Comes in handy for reading the fine map print, especially when you are long-in-the-tooth, like me, and the eyes start to go bad. It can also be used to start a survival fire, providing the big heat-tab-in-the-sky is shining.

An adjustable declination setting. Determine the declination for your AO, set it into the compass once, and forget it. Big time saver and one less mistake to make.

Sighting apertures and wires between the base and hinged lid.

Most compasses are hemisphere specific. A compass made for the northern hemisphere will not work in the southern hemisphere and vice-versa. You can, however, buy a special compass that will work in both.

For example: The Suunto MC-2 360/D/L/CM/IN/NH  has/built-n Declination adjustment/Luminous dial/inClinometer/INch scale/works in the Northern Hemisphere. The Suunto version for both north and south hemisphere will have the letters NH/SH or G for Global. Each uses a different method of needle stabilization.

If you have any interest in land navigation and are planning a compass purchase, visit your local sporting goods/backpacking store and puts your hands on one first. Usually someone behind the counter will have some experience with one. Another good source of information is a local orienteering/hiking club.

I have updated this post to include this Youtube video that I think will help. It is very well done.

http://www.youtube.com/watch?v=SI-dTsi5nhQ

 

 

 

 

Why land navigation?

Posted: 12/14/2014 in Land Navigation

I’ve recently noted several comments on different blogs asking why all the emphasis on land navigation. Why not just learn your Area of Operations/Area of Interest (AO/AI) like the back of your hand, because you will most likely never venture out of it during WROL anyway. Well, Pilgrim, my best short answer is; land navigation is a valuable skill, that is easily learned and mastered with practice, over time. And like any skill, it makes you a more well-rounded and valuable asset to any team. Why do I need to become familiar with the AK/SKS/Mini-14/FN-FAL/HK systems and every sidearm/shotgun I can get my hands on since I only have an AR-15 ? You never know what you might pick up off of the battlefield.

My best long answer; it is very difficult, even for folks experienced in land nav. to navigate at night, in bad weather, with little or no illumination over broken terrain.  Add to that; while humping ruck, tired and hungry. Let’s look at some scenarios.

Scenario 1:  Your retreat four man R&S patrol is patrolling the ridges surrounding the outside of your AO when they are forced to deviate from their planned route by the unexpected presence of a large group of armed men. They radio in a SALUTE report to back to your group. The OPFOR group’s size, movement formation and route forces your patrol to evade into an area they are unfamiliar with during the night. Come first light, they find themselves in a heavily wooded area surrounded by low mountains. They must now determine their present location and plan a route of return to your retreat. If they can patrol to one of the mountain peaks, they can orient their map to grid north and either terrain associate or re-section their present location and then plan their route back.

Scenario 2:  Your groups ability to make trips to the local barter market have been disrupted by the presence of vehicle mounted harassment/shakedown patrols by groups of local thugs that have recently escalated to include the murder and kidnapping of folks from adjacent groups. After surveilling their operation along different routes for several weeks you determine enough information about them to conduct an early morning ambush of their largest group along a road. This mission will be conducted by several groups with your providing leadership.

Without land nav skills, how will you do your leaders recon of the ambush site, as per SH 21-76 (my favorite, the 1992 version), emplace your security element with eyes-on the objective and find your way back through the release point and then back 300 meters to the ORP at 0200 in the morning, in the rain, and fog, with zero illumination? Or, if you choose to stay on the objective, and send a subordinate leader back to the ORP whereupon he must then lead the rest of the patrol back through the release point to the ambush site, how does he find his way back to the ORP and then subsequently return to the release point? If you’ve not taught him the fundamentals of night land nav he will either A; go off course trying to find the ORP and then decide to sit tight until daylight ruining the ambush opportunity or stumbles up to the ORP off the expected azimuth, whereupon the patrol fires him up and you have a blue-on-blue catastrophe. Or B; he manages to find the ORP and then leads the patrol off course to the ambush site and they stumble upon the road at a different location ruining the ambush and subjecting them to compromise by a vehicle mounted OPFOR patrol.

Scenario 3:  You are asked over your pre-established radio net by the folks in a neighboring community to provide mutual assistance in order to deal with the Leroy Jenkins Gang (thanks Sam) by conducting a raid on their compound. The gang has been ravaging the general area, but has left your group alone due to the severe ass-kicking they took the first time they ventured into your AO. You are going to meet up with your neighbors in the middle of the night at a particular farm outside of your AO. They, being somewhat familiar with land navigation give you the 10 digit grid coordinate to that location. Using maps of the area outside of your AO, which your group ordered and stored well ahead of time, you must now plan a route of march, through unfamiliar territory, to your link up and after the mission is complete, in keeping with good tactics, you must have planned a different route of return to your retreat. Then you must execute that movement under cover of darkness, through heavily wooded terrain in order to mask your movement for two reasons; you do not want the gang to realize part of your force is absent from your retreat thus making it vulnerable, they have their snitches in the area you know, and you don’t want the gang to realize something is afoot making them wary. Surprise is an important combat multiplier.

So, three scenarios regarding the importance of land navigation. I apologize that they all involve combat patrols, but that’s my frame-of-reference. I’m sure with some thought you can come up with other reasons. I would suggest looking around online for land navigation sites to include the land nav primer at Max Velocity’s site. Then go out and take a land nav class or join an orienteering club for some hands-on experience.

Have fun boys and girls.