“Without more data on degradation due to UV and oxidation I am assuming a five year service life. (Probably conservative). The cap shroud is the critical one. In 9mm the design load is about 17% of MBL. )The intermediate and lowers are way over spec.) I want to use turnbuckles rather than deadeyes and a 5/8” turnbuckle seems to be a fair match to 9mm Dux. It has an adjustment range of about 5“. Allowing 2” to take up the first year of settling in leaves .75“ per year for the remaining 4 years.”