A. Ropes and accessories

  1. What difference is there between Mastrant Classic ropes (P, Q, S, C, R) and Mastrant-M? The difference stands in parameters. Ropes from the Classic product line are the basic ropes optimized for a good price to performance ratio, whereas type M has approximately doubled strength and simultaneously half the stretch compared to type Classic. They are also lighter because the rope core is made from high-strength Dyneema® fibers.
  2. When is it better to use Premium rope (M) instead of Classic? When one needs the lowest weight and wind resistance (long ropes holding wire antennas, or supporting large beam elements, or expeditions where low weight is crucial). Also when the anchor points on the ground need to be placed close to the tower (less than 50% of the guy point height – depending on the type of tower – the higher stress needs to be calculated individually) and finally, for any big towers with big antennas.
  3. When I am looking at Dyneema ropes for maritime use, the strength eg. with 10 mm Dyneema is well over 10.000 kg, but your Mastrant M rope with a similar diameter has "only" 3.850 kg strength, even the core material is the same. Can you explain why? There may be several reasons for this difference. The first is that in Mastrant-M ropes, HMPE fibers form only the core. The braid (and any intermediate braid) is made of Polyester fibers, which have lower strength (but other necessary properties for which they are used). The reason may also be the methodology of measuring strength. Our declared breaking strength of ropes is strength really measured – each production series. It must be always 3% or higher than in our specification. There on the market is also another approach – the theoretical BS calculated based on the specification of Dyneema fiber and number of fibers (diameter). This theoretical strength is always much higher.
  4. What difference is there between Mastrant ropes and Kevlar ropes? Kevlar, like Dyneema®, uses high-strength fibers. While Kevlar is made from aramid the Dyneema® is made from a special sort of PET. Kevlar is not UV resistant and its fibers tend to break when bending over a small radius.
  5. What about comparing Mastrant ropes with Phillystran? Mastrant-P has about 80% of the strength of Phillystran of the same diameter. Mastrant-M has about 30-65% higher strength than Phillystran – but the bigger the diameter the smaller difference. Nevertheless, any Mastrant solution of any strength is many times cheaper.
  6. Can you compare Dacron with your ropes? Our ropes have a cover made from polyester. Polyester is a material, and it is the same material as Dacron (brand name of polyester). Construction of the rope (number of layers, number of strands, fiber angle, manufacturing process, ...) is a different story – the design of Mastrant ropes is adapted so that the abrasion resistance is as high as possible.
  7. What makes Mastrant-M better rope for tower guys than pure Dyneema rope made for maritime use? This question needs more answers:
    1. There are several types of Dyneema. Also, there are other producers (and brands) of HMPE ropes (the chemical principle of Dyneema). HMPE ropes are excellent, but they slightly stretch if they are in great tension for a long time. This property is called creep. This is not a problem for many applications: regular (e.g., once every 6 months) tightening does not matter, or the ropes are not permanently stressed (for example, masts where there is no permanently high tension, but only during strong winds).
    2. In Mastrant-M we use a special version of HMPE fibers – Dyneema DM20. The biggest advantage is that it does not creep. Even though this material is much more expensive than older types of Dyneema or other HMPE fibers, stability is very important for guying so in 2013 we switched to DM20, and Mastrant-M was born.
    3. For guying, there are usually important also mechanical features. Using two (or three in diameters 6 mm and up) layers of materials in the rope significantly increases mechanical durability. Also, pure HMPE rope is “slippery” (on touch).
    4. If you are considering pure standard HMPE rope (Dyneema SK75, SK79, SK99, Nexsteel, ...), also consider our HMPE ropes D-F3.
  8. What is the expected lifetime of Mastrant ropes? The ropes are made of materials with a lifetime of decades. There are installations more than 17 years old among users.
  9. Do I need to buy a complete reel? How long is the rope on the reel? Standard is 100m or 200m of rope on the reel. Some diameters are 31m on the reel. However, we can deliver any length you want (ropes longer than 200m are available on special order). The ropes of standard length are cheaper. Aside from standard ropes, we offer also “ready-made” ropes with thimble compressed-in on one end.
  10. Do you sell, or know of anyone who sells, a guy rope/wire tension gauge/meter? We do not sell measuring instruments for measuring tension in ropes because the available gauges are calibrated for steel ropes and not for synthetic ropes. Another reason is the high price of those that can be used. However, measuring tension is not difficult - we recommend reading the article Rope tension measurement.
  11. Why don't you supply clamps with safety locking nuts? We fully understand your concerns. In reality, if the clips are used properly – and that means properly tightened, it is not possible for the nuts to spontaneously loosen. The reason is that there is always strong counter-pressure caused by the elasticity of ropes. The fact is that the clips were designed by much smarter people than me without washers or locking nuts - and this applies to all types of rope grips. Also, we have never received any feedback that nuts were loosening when installed on the rope, on the other hand, losing nuts during transportation in a pack or pocket is quite common. My personal experience (OL5Y) proves that they will not loosen on the rope if properly tightened.
  12. What is SWL (Safe Working Load), WLL (Working Load Limit), BS (Breaking Strength), SF (Safety Factor)? Wikipedia details here.
  13. Ropes and the sea salt - is it true, that in the marine air will collect sea salt in the rope braids and eventually will become conductive? That is correct - it is true that once the rope gets wet from salt water, it can start to become partially conductive, which can affect the electrical performance of antenna systems. This is an occasional problem with insulators, by the way. However, in the 14 years of Mastrant's existence, we have satisfied hundreds of customers with antennas right on the shoreline, and as far as I know, this temporary change in conductivity has never caused a loss of satisfaction or confidence in our ropes.
  14. Are the BAYCO monofilament ropes better than your Mastrant ropes for guywiring a tower? It looks like the Bayco do not absorbe water. Mastrant ropes are developed for anchoring masts, and the fibres from which they are made (Polyester, Dyneema) do not absorb water in the same way as monofilament. However, water can get into the rope, which is made of thousands of individual fibres. This occurs in a situation where the rope is "loose" - if it is taut, the wetting of the inside of the rope is negligible. The essential difference in favour of Mastrant type ropes is their mechanical properties and therefore their handling, ending, tensioning etc. It is therefore impossible to decide in general terms which solution is better for anchoring antennas. We recommend asking about the experience of users of our ropes in Italy.

B. Preparing, Installation

  1. How far away from the mast should the guy anchors be placed? We recommend that distance be equal to the height of your mounting point on the tower, but no less than 2/3 of it. However, sometimes this is not possible - in this case, a rope with lower absolute elongation and higher strength must be used. At the same time, it is necessary to assess whether the mast used is strong and stiff enough to handle the higher vertical load. We recommend using our calculator to calculate the effect of the anchoring distance on the applied forces. 
  2. What a rope and how long do I need for ...? We offer a free calculation service of ropes strength and length needed for your project. Apart from that, we have online calculators on our web pages which you can use for calculation yourself. These tools are also available in form of an Android application – look for “Mastrant” on the Google Play store. For basic orientation, we have prepared typical installations and recommended ropes: 
  3. What is recommended minimum bend radius of 5mm Mastrant-M and -P? Like if the rope is tied to a chain link coupler? Also, minimum pulley diameter? Generally, we recommend a minimum bending radius the same as the radius of the rope. You can work with knots and the breaking strength still remains approximately double that of Work Load Limit (safe working load). Of course, you can use ropes with an even smaller diameter (not sharp!) but their breaking strength decreases. Regarding pulleys, you are limited by the size of the groove in the sheave. All sheaves for particular rope have a large enough diameter for Mastrant ropes.
  4. I have a Rohn tower and I want to use Mastrant ropes to guy it – which ropes should I use? Refer to: .
  5. I want to replace steel ropes with synthetic ones – which ropes should I use for replacement? Refer to .
  6. What does elongation (stretch) percentage mean? The elongation in our datasheets is a relative change of the length measured between “pre-tension” (10% of breaking strength) and “working tension” (30% of breaking strength). The elongation is almost linear between 10% and 70% of BS.
  7. I have dipoles rigged at about 42 m between much taller trees. These trees move a lot in the wind, so support ropes go through pulleys at each tree, tied down on one end and with a 100 lb weight on the other, but pull forces can be significantly greater when the wind is blowing and the rope moves back and forth a lot. Are any of your ropes suitable for this use? We suggest for this purpose Mastrant-Q 1/4" (6 mm) or Mastrant-P 3/16" (5 mm). Plus quality pulley with a larger sheave diameter and preferably with a needle (ball) bearing (for example, this one). You can also consider a system using elastic ropes designed for outdoor use. 
  8. I am guying a vertical and was only able to buy the 2mm Mastrant-P (larger sizes sold out). My intention is to use a double length on each guy folded back to the common fixing point. As I now have two lengths running in parallel with a strength equivalent to 4mm rope. 1) Will the rope still have the same percentage stretch or is it increased? 2) As I will be running 2 in parallel, is it advisable to leave them running side by side or with a small twist? If you use two 2mm ropes in parallel, you WILL NOT get the strength of 4 mm rope (440 daN). You will theoretically get a strength two times the strength of 2 mm rope, which is 2x 100 daN. Practically the strength will be slightly lower because you will never get the optimal spread of tensions like in the single rope. Regarding your questions: 1) The percentage stretch will not change - it remains the same because the material and construction of the ropes remain the same. You will get a lower absolute stretch. This means that if you load the rope with a force of, for example, 30 daN, it will lengthen approximately half as much as if you use a single rope. 2) It does not matter at all. Choose what is more practical for you.
  9. Is it possible to connect two ASHF12 jaw tensioners (two levels of guys of one mast) directly to the AEN12 fixing eye? The jaws of the tensioner have a gap of 12 mm, the eye is also 12 mm rod diameter, so it should fit - maybe using some pressure, due to the dimensional tolerances. However, it will be a problem to attach two turnbuckles to a single AEN12 eye, as the turnbuckles will be pushing on each other (the angle between the turnbuckles will be relatively small). It will be functional, but the strength will probably be affected. Therefore, I recommend a "spacer" element in the form of ACC08 between the turnbuckle and the eye. Another option is to use two AEN12 lugs.
  10. I lowered my antenna for maintenance and was surprised at how stiff the Mastrant rope had become. Certainly too stiff to untie knots, but it was also completely inflexible, so I could not properly reuse it for shorter lengths. What had happened? This is quite standard rope behaviour caused by airborne dust that normally enters the rope. It has absolutely no effect on its strength. In general: our ropes are stiff in order to have as little elasticity as possible. If the stiffness is a problem (I want to reuse the rope for something else), just wash the rope (you can also wash it in a regular washing machine in a suitable washing bag).

C. Personal safety

  1. What difference is there between particular harnesses? The BASIC harness is a basic safety harness. Comparing to other types it doesn’t contain the adjustable waist belt. The difference between LX2 to LX5 is in flexibility, sling width, the way of fixing (LX4 and LX5 use quick-acting buckles), and comfort (LX3 and LX5 are designed for long periods of use).