Hi Jon – Great question, thanks for reaching out! We published an answer as a special post “NFPA 11mm G-Rope – Is It a Gimmick”

With the advent of G rated 11mm rope many departments have begun to move to the smaller diameters.There are a lot of advantages, including a wider range of auxiliary equipment that works with this diameter, harmonization with professional rope access systems and methods being used in the field, and – as you so aptly point out – lighter weight and less cost.However, there are still many departments who are opting to take things a bit more slowly. This can be a very costly process, because you must also replace all critical life safety components that are diameter dependent at the same time (bollard type descenders and rope grabs.)  However, adjustable friction devices such as the brake rack are more forgiving, and the same size device can be used on both diameters of rope.As far as performance properties… 11mm (and lower) diameter ropes have been permitted in context of NFPA for over a decade, and have been used in mountain rescue, cave rescue, rope access, and industry for even longer. The durability, abrasion resistance, flexibility, and stretch of an 11mm rope are all engineered features, just as they are in a 12.5mm.  I can show you 11mm ropes that are more durable than a 12.5mm rope, and vice-versa, just depends on materials and construction. For greater durability, choose a thicker sheath (ie, fewer carriers) and stiffer (more tightly woven) kernmantle rope, for greater flexibility choose a thinner sheath and more loosely woven rope. Elongation is measured as a ratio against MBS, so you should find these aspects comparable.

I hope this answers your questions… feel free to reach back out if we can offer further clarification or additional perspectives.

Do you see a lot of Fire Company’s now purchasing this over 1/2 rope? Do you see 1/2” rope being phased out over the next 5-10 years? My fire company will possibly be coming into funding which would give the chance to switch over to 7/16 and get away from 1/2 rope. I am looking for this information so we can make the correct decisions moving forward regarding equipment purchases.
I do like how 7/16 is so much lighter and cheaper while still holding all the same properties as 1/2 rope such as strength, abrasion resistance and stretch. Are you seeing any disadvantages of 7/16 over 1/2 rope?

Thanks for your input.

Jon Isenberg