You guys might also enjoy this video from Smarter Everyday about pullies. https://www.youtube.com/watch?v=M2w3NZzPwOM Jamie Hughes WA7JH Phone: (360) 362-4575<tel:+13603624575> From: PSDR <psdr-bounces@hamwan.org> On Behalf Of John C. Miller Sent: Monday, August 17, 2020 14:34 To: Puget Sound Data Ring <psdr@hamwan.org> Subject: Re: [HamWAN PSDR] Shout-out for Blyn workparty yesterday Hello all, FYI - I've attached a PDF conceptual diagram of the 2:1 lifting rig that we used at Blyn to lift the fully assembled cross-arm assembly with sector with two people lifting. The rig employed one 600ft spool of kernmantle 8mm rope, 3 single pulleys, and a tree strap wrapped around a big stump as an anchor point. The load lifted was roughly 70lb, but the effective weight to the lifters was a bit more than half of that weight, owing to some friction. We also used rope ascenders to grip, pull and hold the lift rope. My observations of using ascenders: - One person alone with an ascender was able to easily and reliably hold the entire load in place while the other lifter re-positioned; - An ascender acts as a safety device that limits how far a load will fall if lifters stumble or lose their grip. Given that (at Blyn) we were having to pull walking over fallen trees, stumps, and down an uneven slope, this extra safety measure was welcome; - An ascender can be used to lock the load in place at any point during the lift (See diagram). This is helpful in that you are not reliant on human strength alone to keep the load secured, and the load can be held in place indefinitely as required by the tower climbers. I think that the ascender is particularly helpful with limited human-power doing the lifting. Speaking for myself, I may not have had enough physical strength to get the job done without use of a rope ascender. https://www.petzl.com/US/en/Sport/Ascenders/ASCENSION<https://nam01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.petzl.com%2FUS%2Fen%2FSport%2FAscenders%2FASCENSION&data=02%7C01%7C%7C8ac35ccba1b24533612408d842f53fe5%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637332968539538155&sdata=p4vt1wFZjsu0cQPVITfzwylNVhAWagNzXDkfqs5vJ5U%3D&reserved=0> p.s I also attached a diagram for a 3:1 mechanical advantage lifting rig, but the rope starts getting a little messy using this setup. p.p.s. I put up a temporary 30dBi dish pointed at Blyn S1, and got about -70 dBm with just rough aiming using the LEDs on the radio. - John Miller kx7jm ---- On Sun, 16 Aug 2020 22:10:46 -0700 Doug Kingston <dpk@randomnotes.org<mailto:dpk@randomnotes.org>> wrote ---- This is a grand thank you to the dedicated work party that attended at Blyn yesterday for 9-10 hours yesterday (plus travel time). It was a big success Here is what I remember we accomplished: * Lifted a fully assembled cross-arm assembly with sector to 90ft * Reterminated 5 cables into surge protectors, and dressed all cables * Relocated a repeater antenna impacted by earlier work * Confirmed all HamWAN devices fully functional (3 panels and 2 PtP links) + PTZ camera * No injuries or equipment damage * (and probably more that Dale or Bart can detail) Attending: Bart Kus, John Miller, KX7JM Dale Nelson, AH6ET Elaine Bradtke, KG7CME Doug Kingston, KD7DK Mike, our site sponsor was onsite as we commenced operations but needed to leave shortly after we started due to a serious family emergency. Our sympathy goes out to him and his family. -Doug- _______________________________________________ PSDR mailing list PSDR@hamwan.org<mailto:PSDR@hamwan.org> http://mail.hamwan.net/mailman/listinfo/psdr<https://nam01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fmail.hamwan.net%2Fmailman%2Flistinfo%2Fpsdr&data=02%7C01%7C%7C8ac35ccba1b24533612408d842f53fe5%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637332968539548145&sdata=PdnNIlGc5AuGICTgUX74S6%2F4865FvSjMpbDuNcRt60I%3D&reserved=0>