רב הרשל שכטר – גנות אגוז

…אך בזמן דאיכא תכלת, שאז צריכים לדקדק היטב בכריכות, אשר זהו הדין של פתיל הנזכר בקרא, אז מסתמא צריכים לנהוג כדעת רוב הראשונים לעשות לכה”פ ז’ חוליות, ולעשות בין כל חוליא וחוליא קשר גמור של קשר ע”ג קשר, (כמנהגנו בזה”ז, דמ”ט נשנה את זה), ובכל חוליא יהי’ מינימום של ג’ כריכות (וכמבואר שם בגמ’ לעיל – וכמה שיעור חוליא, כדי שיכרוך וישנה וישלש.) ובודאי אם יעשה ז’ חוליות, ובכל אחת ז’ כריכות, יצא בזה לכו”ע, אך הרבה פעמים אין החוטים די-ארוכים לעשות מ”ט כריכות יחד עם ט”ז קשרים (כלומר, ח’ פעמים קשר ע”ג קשר, וכנ”ל), ולכתחילה מן הנכון שיהא חלק הכריכות כשליש מאורך החוטים, וחלק הענף שני שלישים. אכן אם יעשה לכה”פ החוליא  הראשונה עם ז’ כריכות, ושאר החוליות עם ג’ כריכות, ירויח בזה במקצת, דמעיקר הדין סגי בחוליא אחת לעיכובא, והוספת ד’ הכריכות הנוספות שבחוליא הראשונה לא יגרום למעט כ”כ את אורך החוטים

Rav Hershel Schachter — Ginat Egoz

“…However, when Tekhelet is available, at which point one must be especially careful with the wraps, since this is the halacha of the petil mentioned in the pasuk, it would seem that one should follow the opinion of the majority of the Rishonim and make at least seven chulyot. Between each chulya and the next, one should make a full knot consisting of one knot on top of another, as is our custom today — for why should we change that? Each chulya should contain a minimum of three wraps, as explained earlier in the Gemara: ‘What is the minimum measure of a chulya? Enough to wrap once, repeat it, and do it a third time.’

Certainly, if one makes seven chulyot, with seven wraps in each one, he will fulfill the requirement according to all opinions. However, the strings are often not long enough to make forty-nine wraps together with sixteen knots — meaning eight sets of double knots, as explained above. Ideally, the wrapped portion should comprise approximately one-third of the total length of the hanging strings, while the anaf, the loose portion, should comprise the remaining two-thirds.

However, if one makes at least the first chulya with seven wraps and the remaining chulyot with three wraps each, there is some advantage to doing so. Strictly speaking, only one chulya is absolutely required, and adding the four additional wraps to the first chulya will not reduce the remaining length of the strings by very much.”

Notes:

• A “single knot” is made by taking the four strings on one side of the garment and the four strings on the opposite side and tying them together with a simple knot.
• The first chulya is made by taking one white string from among the eight hanging strings and wrapping it around the other seven strings three times. Then take one Tekhelet string from among the eight strings and wrap it around the other seven strings four times. These wrapping strings are called shamashim. Because this method requires so many Tekhelet wraps — forty-seven in total — a second long Tekhelet string is provided to serve as an additional shamash. Accordingly, one Tekhelet shamash should be used for the first four chulyot, and the second Tekhelet shamash for the final three chulyot.
• A Tekhelet chulya is made by taking a Tekhelet shamash and wrapping it around the other seven strings seven times.
  The final chulya is made by taking a Tekhelet shamash and wrapping it around the other seven strings four times, and then taking the white shamash and wrapping it around the remaining seven strings three times.
• A total of seven chulyot are shown here; one may make as many as thirteen. However, one should make sure that the wrapped and knotted section comprises approximately one-third of the total length of the hanging strings, measured from the first knot to the ends of the strings.
• When tying the final knot, be sure to separate the four white strings to one side and the four Tekhelet strings to the other.