1080-00-108-1173 Camouflage Screen Support System Masts

Those of your who have read my former web site and blog posts may recognize the following paragraph:


The Cape Cod Packet Group had good information on these masts, guying information, and deployment. They use one 1080 mast set for a G5RV in an inverted V configuration. There was also a link on the site to another guy ring design. If deploying a G5RV in this manner 2, 10 ft. or longer crappie poles can be installed at the ends to keep the ends out of reach or ropes may be affixed to the ends and stretched out to anchors to keep the ends safely out or reach. Anyone know what happened to the CCPG or their site?


The CCPG still has a site, but the mast information is not there.
I was searching on the NSN and found the original web page HERE!
I hope the link works. This page shows the G5RV configuration I have been using with the

1080-00-108-1173 Camouflage Screen Support System Masts and my AB155-A/U mast using the tripod adapter.



Finally, if you want to compute the minimum guy length use the Pythagorean theorem: one side of the right triangle formed by the mast and the other is the ground. Determine how high you will make your mast. This is side a of the triangle. Then measure the distance from the mast base to the guy anchor. This is the other leg of the right triangle, side b. The guy is the hypotenuse, c. The advent of calculators made this really simple. Remember doing square roots long hand or with a slide rule? The theorem states side a squared plus side b squared equals side c squared, but we are interested in the length of c -- not the square.  This requires taking the square root of the sum of the squares of a and b.

Now you know the height of your mast and you know where you want the base and how far away you will place the guy anchor from the base. All anchors will be equally spaced from the base.

For example, 50 ft to the top of the mast, 35 ft from the base to the anchor. This will be the length of the top set of guy ropes.

Square each distance: 50 squared is 2500. 35 squared is 1255.

Add the two squares (2500 + 1255) = 3725. This is the square of the hypotenuse.

The guy is the hypotenuse of the right triangle. To get the answer for the length, take the square root of the sum of the squares which equals 61.033 feet.

Now add how much extra you will need to fasten the rope to the mast and to the anchor.

I use spring clips at the mast ends of the guys fastened with a bowline knot. For this I allow one foot. At the anchor end I use a Taunt-line hitch or other sliding knot that will bind and not slip under tension. (see my post from 9 December 2016, Military Masts, Part 2)  I allow anywhere from 3 to 5 feet extra at this end. My total length would be 65 to 67 feet. Many times I use more depending on how many guy lines I get from a spool of rope.

Do this for each set of guys.  For example for a 44.5 foot mast using 12 sections (44.5 inches long each) of the  1080-00-108-1173 masts the bottom guys would be 4 sections high or 14.83 feet, the middle ones 8 sections high or 29.33 feet, and the top would be 12 sections high or 44.5 feet.  It is much easier thinking 4 foot per section than the odd feet and inches so I use 16 feet, 32 feet, and 48 feet.

Each section is 44.5 inches to 44.625 inches long when assembled.  The multiples are repeating decimals that never end.  Rounding to 2 places is good enough.  Using 48 inches or 4 feet as the length of each section of calculations makes calculating the lengths much easier.

If you doubt your math, lay out a mast on the ground, measure (or mark) heights and the base to anchor distance, and use a 100 meter/330 foot tape from Harbor Freight to measure the distance from where you want to place your guys on the mast to the anchor point.

This could even be done on an empty parking (if you have permission to use the lot) lot using chalk, but you need to be certain that the distance from the top to the bottom of your chalk line mast is straight and the distance from your chalk line mast base to the anchor point is a square angle (90 degree angle).  Do one side of the mast.  Then you know how much rope you need for one set.  Multiply the total of this set by how many guys you want to make.

Military Antenna Masts Part 5, AB155A/U

After working a few Field Day operations with local clubs I decided to get a few masts of my own.  I started with the LCSS support poles shown on the mast information page and while searching the web for information on them I found references to the MS-44 mast sections.  Later I found they were part of the AB-155/U mast that was issued with the AN/GRC-26 Radio Set.  Apparently these mast sets as well as the AN/GRC-26 were issued is several series.  I found reference to the AB-155, AB-155A/U and AB-155B/U.  They all seem the same except for the issue quantity of some of the hardware.  I have 2 different MS-44 mast sections.  I have 2 sets made from steel and several sets made of aluminum.  I managed to find several sets of un-issued surplus MS-44 sections made in 1982 or newer and tagged in 2004.

Here is the website I found one of the manuals: www.militaryradio.com

and here TM 11-5820-256-10

               TM 11-5820-256-20      

               TM 11-5820-256-24P

The following is issued with the AN/GRC-26 

5985-507-6261         6         Mast, AB-155/U, AB-155A, B/U

Each of the following is issued with each AB-155*/U listed by FSN, Quantity Required, Quantity Issued and Item.

5920-497-8634         1         1         Carrying Device MX-387/GRA4: SC-D-28057                                                                                                                                                  

5820-221-1563         1         1         Cover CW-124/GRA4: SC-D-28056                                                                                                                                                              

5325-497-8640         4         4         Guy Fastener MX-379/U: SC-D-28050                                                                                                                                                            

5820-224-4638         3         3         Guy Plate MX-378/U: SC-B-28049                                                                                                                                                   

5975-503-0702         4         4         Guy MX-381A/GRA4: SC-D-28053                                                                                                                                               

5975-538-0199         4         4         Guy MX-382A/GRA-4: SC-D-28053                                                                                                                                               

5975-503-0733         4         4         Guy MX-383A/GRA4: SC-D-28053                                                                                                                                               

5985-228-8064         1         1         Halyard MX-516A/GRA-4: SC-D-28054                                                                                                                                           

5120-203-4656         1         1         Hammer, engineers, Double Face 2 1/2 lb; GGG-H-86, Type X, Class 1                                                                                           

5820-240-8233         1         1         Mast Base AB-154/U: SC-DL-182925                                                                                                                                           

5985-636-2420         1         1         Plate, Mast Base: SC-B-84299                                                                                                                                                           

5820-227-7168         8         8         Mast Section MS-44: SC-D-1155                                                                                                                                                       

4030-187-5263         4         4         Guy Stake; Metal; 18 1/4 in. lg: SC-DL-33399                                                                                                                               

5510-187-5267         4         4         Stake, Wood; 1 1/2 in. dia X 30 in. Ig.: SC-C-22005                                                                                                                                        

5985-453-9439         1         1         Tripod Adapter Mast AB-1089( )/U: DL-SC-B.459357
                                           

This is an old issue AB-155/U.  As seen from the photo the issue quantity has changed as well as the design of the guy fasteners and base plate. I have one of these complete.  I also have others that I am still assembling. 
The military states using these at 40 feet.  I am working on making at least 2 sets that will be 50 feet.  Plans are to use 1/4 inch diameter dacron rope rather than 3/16 inch and adding at least one level of guys.
Keeping the standard 40 feet AB-155/U and adding 2 sections the top could be guyed which would require only one additional set of special length guy ropes rather than changing the overall guying and making custom lengths for the 50 ft. masts.

The 1089 tripod adapter is shown below:

 This is one I bought from a surplus dealer on Ebay and repainted.  I have several of these and all are modified.  The originals were made of steel as best I can determine.  They were welded and tack-welded.  The next series was either as shown above or epoxy fastened center with the same crimped leg receiver tubes.  The epoxy ones are painted with gloss olive drab paint and the center tube can break loose.  I found one on another site that showed an original and it was like mine (made with epoxy) that I took apart and welded.  Also notice on the above photos the center tube isn't welded to the top plate. 
 The steel AB-1089/U.  The center tube is welded at the bottom and under the top plate.  The leg receiver tubes are welded to the plates. See figure 2-17 on page 53 of the pdf file for the AB-155/U.  Link is at the bottom of the page.







 
The one made with epoxy, dismantled, epoxy removed, welded and repainted.
According to the TM a mast erected using the tripod adapter will withstand 25 MPH winds without guys. 

This is my steel MS-44 set in BG-176/U carriers.  I found this set on Ebay a few years ago. I am not sure if this was ever part of an AB-155/U.
The AB-155/U is a 40 ft. mast and each mast set shown makes only a 35 ft. mast.
TM-11-5820-256-10 and from the Fremont CA CERT group one of the best concise instructions for raising one of these masts Assembling the Jungle Tower
I also found some information on the AB-155/U, OE-254 and more on a CA ArmyMARS site that I have not been able to find lately.  Maybe the site is down.
 Some of the items on this page came from Ontario Surplus (link on Mast Information page), Baran's Military Surplus (Jbaran33on Ebay) and Austin Avation/HMMWV Surplus (beltfed34 on Ebay) as noted on the mast information page rope comes from Jerry at Bayway Deals, please see the link on the mast information page.



 Originally posted 7May10