Guy attachment plates:
These can be made from large stainless steel flat washers. I copied the MX-378/U guy plate for the MS-44 mast sections. Part number 92141A041 from McMaster-Carr (www.mcmaster.com) is a 3.25: O.D. flat washer for a 1.5" screw. It has an inner diameter of 1-9/16". This works for the fiberglass and the aluminum poles.
The MS-44 mast section male end has a smaller outside diameter. It is only 1.325" so for the MS-44 I used 92141A049. This washer also has an O.D of 3.25", but it is for a 1.325" screw so it has an I.D. of 1.5"
Both of these washers are .140" thick which is nearly twice as thick as the MX-378/U.
The hole pattern is the same as the MX-378/U. If the military uses 4 guy ropes then that must be the safe way. Besides this gives 5th hole to attach a pulley for raising / lowering the antenna.
Hole size, circumference, and pattern will be detailed as soon as I can post a drawing of them.
Remember if you make things for your mast YOU are responsible for your actions and the parts used. What is on this site is what I use. Anything can fail. Failure of a mast can be just a mast falling and damaging itself to a catastrophic event.
The MS-44 mast section male end has a smaller outside diameter. It is only 1.325" so for the MS-44 I used 92141A049. This washer also has an O.D of 3.25", but it is for a 1.325" screw so it has an I.D. of 1.5"
Both of these washers are .140" thick which is nearly twice as thick as the MX-378/U.
The hole pattern is the same as the MX-378/U. If the military uses 4 guy ropes then that must be the safe way. Besides this gives 5th hole to attach a pulley for raising / lowering the antenna.
Hole size, circumference, and pattern will be detailed as soon as I can post a drawing of them.
Remember if you make things for your mast YOU are responsible for your actions and the parts used. What is on this site is what I use. Anything can fail. Failure of a mast can be just a mast falling and damaging itself to a catastrophic event.
Here is a comparison of one of the homebrew guy plates beside a G.I. MX-378/U guy plate.
For what it is worth...while searching on my call I came across a site where someone wanted to know the weight of one of the SS washers. For what ever reason it is not important if one is using one of the Military masts since they all weigh over 2 pounds / section, but here it is: after machining the SS weighs 3.5 Oz. and the original MX378/U ( which will not fit the 1080 mast sections) 2 Oz. MX-378's are made of steel. Considering the weight of the mast sections and ropes the weight of a stainless steel washer is minuscule.
The good fiberglass sections weigh about 2 lb, 2oz and the aluminum are 2 lb, 11oz.
Guy Ropes:
Guy ropes can be made from 3/16 inch dacron rope. This is the same size used by the military. Rope lengths have been computed and sized using the U. S. Army TM for the AB-155/U series of masts. One 500 ft spool will make a set of guys for one mast (10 to 12 #1080 sections 25 ft. anchor distance). There are several suppliers for this rope, however not all rope is created equal. The army uses twisted braid. I use static kernmantle double braid. It is much stronger for its size than other braids and it holds up very good to field use. Hollow braid is a bit better suited for halyards although I use the same for guys and halyards. Twisted braid twists.
Guy ropes can be made from 3/16 inch dacron rope. This is the same size used by the military. Rope lengths have been computed and sized using the U. S. Army TM for the AB-155/U series of masts. One 500 ft spool will make a set of guys for one mast (10 to 12 #1080 sections 25 ft. anchor distance). There are several suppliers for this rope, however not all rope is created equal. The army uses twisted braid. I use static kernmantle double braid. It is much stronger for its size than other braids and it holds up very good to field use. Hollow braid is a bit better suited for halyards although I use the same for guys and halyards. Twisted braid twists.
For AB-155 masts I use 1/4 inch dacron rope. A set of guys requires more than 500 ft. since I use 10 MS-44 sections rather than the normal 8 sections. 8 sections will make a 40 ft. tall mast and one 500 ft. spool of rope will make one set of guys. Military manuals and mast kits use 3/16 inch diameter rope. My preference is for the larger diameter since I add more sections.
Best rope I found comes from Jerry at Bayway Deals. http://www.freewebs.com/workingstiff/500spooldoublebriaddacr.htm
The link is to his rope page. He also can supply some hardware and complete masts and guy kits. His site is loaded with mast information.
I have bought several spools of rope from him none were ever short and not a single booger, splice or other flaw. He also has other mast supplies at reasonable prices. Check out the mast base for a trailer hitch on his site.
For those of you not familiar with rope terminology...rope boogers are places in the braid (sheath) where the mantle (core) pokes through as bumps,
wads, and other deformations. It means the kern was damaged during manufacture and the rope has a weak spot there requiring a cut or splice. Now you end up with a short piece because a cut is required or you cut it an make a splice and weaken the rope.
Rope care is an entire different page so not much here. Be careful with knots. Each knot can weaken a rope by about half its strength so tie them correctly and use the correct knot. I use bowlines for most of my knots. I also use ring hitches, clove hitches and rolling hitches for many temporary applications. These hitches as well as a cow hitch or a prusik knot come in handy for attaching guy ropes to a mast where a guy plate is not used (such as a Jackite telescopic mast). Watch out for mast rotation and ensure the rope cannot slip down along the mast. I would not use any rope tied around a 1080 or MS-44 mast section unless I only needed to stabilize 10 or 20 feet of mast for a quick and dirty deployment. Also no matter what knot you tie; always safety the rope end.
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 link is to his rope page. He also can supply some hardware and complete masts and guy kits. His site is loaded with mast information.
I have bought several spools of rope from him none were ever short and not a single booger, splice or other flaw. He also has other mast supplies at reasonable prices. Check out the mast base for a trailer hitch on his site.
For those of you not familiar with rope terminology...rope boogers are places in the braid (sheath) where the mantle (core) pokes through as bumps,
wads, and other deformations. It means the kern was damaged during manufacture and the rope has a weak spot there requiring a cut or splice. Now you end up with a short piece because a cut is required or you cut it an make a splice and weaken the rope.
Rope care is an entire different page so not much here. Be careful with knots. Each knot can weaken a rope by about half its strength so tie them correctly and use the correct knot. I use bowlines for most of my knots. I also use ring hitches, clove hitches and rolling hitches for many temporary applications. These hitches as well as a cow hitch or a prusik knot come in handy for attaching guy ropes to a mast where a guy plate is not used (such as a Jackite telescopic mast). Watch out for mast rotation and ensure the rope cannot slip down along the mast. I would not use any rope tied around a 1080 or MS-44 mast section unless I only needed to stabilize 10 or 20 feet of mast for a quick and dirty deployment. Also no matter what knot you tie; always safety the rope end.
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?
Other types of rope such as the poly rope available from Harbor Freight works fine for temporary deployment and for halyards. The disadvantage of poly rope is it deteriorates in sun light. Be sure to check the tensile strength of any rope to ensure whatever is deployed will stay deployed. Poly rope is not as strong as Dacron rope of the same diameter and weave (twisted, braided, etc.).
I have not done much here on knots. I hope to add more. A good place to begin is at Animated Knots
One of my favorites for guy lines when I do not have a dogbone (which I trust on tents and not on masts) or a commercial or military guy rope tightening device is a Taunt-Line hitch
Click the thumb nail for a larger image in a new window. There are several knots I use and will add them as time allows. Practice tying any knot you decide to use before you need to use it. That way you can test 1/ your skills and 2/ the integrity of the knot. Remember if you choose to use any knot from this or any other site it is your responsibility and liability not mine or any other sites. Any knot not tied correctly --especially in a guy rope-- can be fatal! Always safety your knot no matter what kind you tie.
I also found the Taunt-line and mid-shipman's hitch from Rope Works while the searching for information on how to show how a taunt line hitch is tied. There are also instructions for the mid-shipman's hitch with is noted to be better than the taunt-line. I have used both with the dacron rope I use and neither have slipped even during Florida thunderstorms.
No comments:
Post a Comment