கொல்லிமலையில் 70 கொண்டை ஊசி வளைவுகள் ஏன்? | Kolli Hills Hairpin Bends: The Science

நாமக்கல் மாவட்டம், கொல்லிமலைக்குச் செல்லும் சாலையில் 70 கொண்டை ஊசி வளைவுகள். நேராக ஒரு சாலை போட்டிருக்கலாமே? சரிவு சதவீதம், சரிவில் புவியீர்ப்பு விசை, சாய்தளம் என்ற எளிய இயந்திரம், கொண்டை ஊசி வளைவின் வடிவமைப்பு (இந்திய சாலைக் காங்கிரஸ் வழிகாட்டுதல்கள்), வளைவில் ஏன் மெதுவாகச் செல்ல வேண்டும்: அனைத்தும் அனிமேஷன் விளக்கங்களுடன். The ghat road to Kolli Hills (Namakkal district, Eastern Ghats) climbs roughly 900 m in about 20 km through 70 numbered hairpin bends. This video explains, with animated diagrams, why the road zigzags: slope in percent, the share of gravity that pulls a vehicle back on 18% and 4.5% slopes, the inclined plane, why tight hairpins fit a steep hillside, and the Indian Roads Congress guidance for hairpin bends (IRC:52-2019): inner radius at least 14 m, slope at the bend within 2.5%, at least 60 m between hairpins and a design speed of 20 km/h. English subtitles on screen. CHAPTERS 0:00 Intro: 70 bends on one road 0:20 Where: Kolli Hills 0:50 How steep is the road? 1:17 Gravity on a slope 1:42 The trick: stretch the road 2:06 Hairpin design 3:06 Slow down on the bends 3:41 The lesson தொடர்புக்கு: draran.online REFERENCES (APA 7th) Bikeclimbs. (n.d.). Kolli Hills climb, Solakkadu, Tamil Nadu. Retrieved November 10, 2026, from https://bikeclimbs.com/climb/india/tamil-nadu/sendamangalam/solakkadu/kolli-hills Dangerous Roads. (n.d.). Kolli Hills is the road with 70 hairpin turns. Retrieved November 10, 2026, from https://dangerousroads.org/asia/india/3311-kolli-hills-road.html evo India. (n.d.). Great driving roads: Hyundai i20 to Kolli Hills. Retrieved November 10, 2026, from https://evoindia.com/features/hyundai-i20-to-kolli-hills Indian Roads Congress. (2019). Guidelines for the alignment survey and geometric design of hill roads (IRC:52-2019, 3rd rev.). Indian Roads Congress. Namakkal District Administration. (n.d.). Kolli Hills. Retrieved November 10, 2026, from https://namakkal.nic.in/?p=22837 Wikipedia contributors. (2026). Kolli Hills. In Wikipedia, The Free Encyclopedia. Retrieved November 10, 2026, from https://en.wikipedia.org/wiki/Kolli_Hills Natural Earth. (n.d.). 1:10m cultural vectors: Admin 1 states and provinces; 1:50m land [Data set]. https://www.naturalearthdata.com/ NOTES ON CLAIMS - 70 hairpin bends with numbered signboards (for example "14 of 70"): evo India; Dangerous Roads; Onmanorama. - Location: Namakkal district, Eastern Ghats; elevation 1,300 m; ruled by Valvil Ori around 200 CE, praised as one of the seven great patrons (Wikipedia, Kolli Hills). The district website gives about 1,200 m; Onmanorama gives 1,000–1,300 m and wrongly places the hills in the Western Ghats. - Climb: Dangerous Roads gives Karavalli (238 m) to Solakkadu (1,198 m), 960 m in 20.4 km, average 4.70%. Bikeclimbs gives 19 km, 837 m, average 4.4%. The video therefore says "about 20 km", "about 900 m" and "about 4 to 5%". - 18% for 900 m in 5 km, "four times steeper", "about one-sixth" (sin(atan 0.18) ≈ 0.18) and "about one twenty-second" (sin(atan 0.045) ≈ 0.045) are my calculations. The 5 km road is hypothetical. - Engine strain, wheel slip and brake overheating on steep descents are general vehicle physics; no specific source is cited. - Hairpin values are from IRC:52-2019, clause 6.10: minimum design speed 20 km/h, minimum inner radius 14 m, gradient at the bend 1 in 40 (2.5%) maximum, at least 60 m between successive hairpins, widening at the apex. The Kolli road was built long before these guidelines, so the video presents them as current guidance, not as a survey of this road. - Inner edge ≈ 44 m (π × 14 m) and outer edge ≈ 68 m (7.5 m wide road) are my calculations. "2× speed = 4× grip" and 0.22 g at 20 km/h vs 0.90 g at 40 km/h on a 14 m radius use a = v²/r (calculated). - Single-vehicle bends: Dangerous Roads. Honking before blind corners: evo India. Low-gear advice is general safe-driving practice. - Goats and herders zigzagging up slopes is a general observation, not a cited claim. - Map: Natural Earth, WGS 84 (EPSG:4326); positions approximate. Road diagrams are schematic (not the real layout). All photographic scenes are AI illustrations; all people shown are fictional.