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| 03-03-15 11:56PM |
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brier1
Knee-Slider
Registered: Jan 2015
Location:
Posts: 7 |
Hog line violation overturned
Class act by Alberta to let team Canada have a throw over after lights were Red for a hog line violation and replay showed it was a malfunction .In the M&M junior final this year Ontario did not get the same ruling consideration as they did at the Brier tonight.
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| 03-04-15 12:05AM |
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dbsdbs
Drawmaster
Registered: Feb 2013
Location:
Posts: 812 |
Was it really Alberta's decision whether to allow another throw? Would hope that was official's decision. But that makes one wonder why there was not a similar decision in juniors.
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| 03-04-15 12:25AM |
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guido
Super Rockchucker
Registered: Feb 2011
Location: Winnipeg
Posts: 1418 |
Carter also thanked the Koe team for allowing the re throw.
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| 03-04-15 12:37AM |
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brier1
Knee-Slider
Registered: Jan 2015
Location:
Posts: 7 |
Class act by both teams but would have been interesting if the Officials had let the violation stand as in the Scotties and the M&M junior final as iit also was clearly released on the replay ?
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| 03-04-15 12:48AM |
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dbsdbs
Drawmaster
Registered: Feb 2013
Location:
Posts: 812 |
quote:
Originally posted by brier1
Class act by both teams but would have been interesting if the Officials had let the violation stand as in the Scotties and the M&M junior final as iit also was clearly released on the replay ?
Did officials ever explain why they let violations stand in Scotties and junior if replay clearly showed no violations? Or do the officials not have the ability to reverse any violation?
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| 03-04-15 12:49AM |
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Gerry
CZ Founder
Registered: Sep 2002
Location: London, Ontario
Posts: 4002 |
Some more on the story, video and a clear imagine showing Rycroft's clean release:
http://www.curlingzone.com/talk/?p=167
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| 03-04-15 02:49AM |
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peteski
Drawmaster
Registered: Feb 2007
Location:
Posts: 631 |
This worries me. These sensors should be foolproof, and I honestly thought they were. Yes, they're better than human judgement, but only if they work. The stakes are very high for these games and you just can't have these things being occasionally faulty.
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| 03-04-15 07:26AM |
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misty1
Supreme Champion!
Registered: Sep 2011
Location:
Posts: 6002 |
i cant recall a year when the rocks mal-functioned this many times. a couple times at the juniors, 4 or 5 times at the scotties and now here.there will,probably be more instances at worlds too
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| 03-04-15 07:51AM |
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AlanMacNeill
Super Rockchucker
Registered: Sep 2011
Location:
Posts: 1064 |
Some sensor questions...
1. Was it the same stone that was malfunctioning at Juniors (more importantly, the same handle, since that's where the sensors are...)
2. I work in IT...electronic gizmos aren't really designed in most cases to respond well to repeated significant collisions...like...oh...high weight triple takeouts...acceleration tends to break electronic things...well...more accurately, sudden deceleration...but the point holds...as such...how old is the defective sensor handle?
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| 03-04-15 09:40AM |
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Guest
Super Rockchucker
Registered: Feb 2005
Location: .
Posts: 1844 |
quote:
Originally posted by AlanMacNeill
Some sensor questions...
1. Was it the same stone that was malfunctioning at Juniors (more importantly, the same handle, since that's where the sensors are...)
2. I work in IT...electronic gizmos aren't really designed in most cases to respond well to repeated significant collisions...like...oh...high weight triple takeouts...acceleration tends to break electronic things...well...more accurately, sudden deceleration...but the point holds...as such...how old is the defective sensor handle?
Good mechanical design should dampen the force on the electronic components. Use of military/industrial electronic components helps too. I would think the CCA has a manufacturing/usage history of each handle.
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| 03-04-15 09:48AM |
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AlanMacNeill
Super Rockchucker
Registered: Sep 2011
Location:
Posts: 1064 |
I concur that good design could work around it...but from what I've seen inside the handles (at least the ones the USCA has, which I assume are similar in design)...there doesn't seem to *be* much of that design in there...it really looked to me like the wires were just routed through the handle, the sensors aren't shock absorbed at all, and the batteries were just wherever they fit...given that, unless something really smart was going on under the covers...I'm not surprised that things are going belly up.
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| 03-04-15 09:58AM |
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Guest
Super Rockchucker
Registered: Feb 2005
Location: .
Posts: 1844 |
quote:
Originally posted by AlanMacNeill
I concur that good design could work around it...but from what I've seen inside the handles (at least the ones the USCA has, which I assume are similar in design)...there doesn't seem to *be* much of that design in there...it really looked to me like the wires were just routed through the handle, the sensors aren't shock absorbed at all, and the batteries were just wherever they fit...given that, unless something really smart was going on under the covers...I'm not surprised that things are going belly up.
Yikes, this sounds scary.
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| 03-04-15 10:46AM |
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Jimbobogie
Drawmaster
Registered: Feb 2014
Location:
Posts: 538 |
First of all, this is one reason why curling is special-kudos to Alberta-it looks like they had made the "re-throw" call before the official even arrived on the scene.
Now about those rocks...
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| 03-04-15 11:14AM |
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hit-n-roll
Harvey Hacksmasher
Registered: Sep 2002
Location: McFarland, Wisconsin
Posts: 90 |
It looked to me like he didn't set it properly before he threw it. That is not a malfunction of the equipment. That is on the player. Pretty sure the rules say you pull the stone in that case. Having said that, I don't have a problem with Alberta allowing them to throw it over. Classy move on their part!
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| 03-04-15 11:19AM |
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AlanMacNeill
Super Rockchucker
Registered: Sep 2011
Location:
Posts: 1064 |
Not sure how you get that off of the video posted, as it doesn't focus on the delivery until just before his push, and most players working with handle stones I've witnessed do the flip as part of their running surface clean and check ritual. The video I saw never even had him checking the bottom of the stone for potential crud...which tells me it was done before the cameras were there.
Once set, the handle is supposed to be "live" for a throw for 60 seconds, so lots of time for that to have been done before the cameras hit him.
There is a visual clue as to whether the handle is live or not, checking for that is one of the things they brief new sensored handle players on...and he isn't even a new Sensored player...so...all told...I'm pretty comfortable saying it's a sensor malfunction, unless there's a different video out there than the one making the rounds.
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| 03-04-15 12:43PM |
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Three
Swing Artist
Registered: Feb 2015
Location: Canada
Posts: 278 |
When the handle fell off the Newfoundland rock on the opening week-end TSN showed the repari guy putting on a new handle. All the wires were exposed and it did not look like there was any shock or vibration dampening material anywhere. For those big weight throws it looked pretty fragile in my opinion as an engineer.
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| 03-04-15 01:53PM |
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Deucey
Drawmaster
Registered: Mar 2005
Location: Calgary
Posts: 612 |
quote:
Originally posted by AlanMacNeill
Not sure how you get that off of the video posted, as it doesn't focus on the delivery until just before his push, and most players working with handle stones I've witnessed do the flip as part of their running surface clean and check ritual. The video I saw never even had him checking the bottom of the stone for potential crud...which tells me it was done before the cameras were there.
Once set, the handle is supposed to be "live" for a throw for 60 seconds, so lots of time for that to have been done before the cameras hit him.
There is a visual clue as to whether the handle is live or not, checking for that is one of the things they brief new sensored handle players on...and he isn't even a new Sensored player...so...all told...I'm pretty comfortable saying it's a sensor malfunction, unless there's a different video out there than the one making the rounds.
When you flip the rock the lights on the handle go green to indicate the rock has been set. Unless I'm mistaken the lights are not on when Carter makes his first attempt which would indicate he hadn't properly set the rock. Technically Koe would have been within his rights to pull that stone. Although I think the rules should be rewritten. If the lights go red you let the stone play out. If the player was clearly no where near the line the play should stand. If he was close then it's his/her own fault for A) not setting the stone and B) cutting it close to the line.
It was a classy move by Team Alberta. The unfortunate part is Koe thought Carter was not making the runback on his first attempt. That's why I think when the rock goes red they should let it play out. If it's a confirmed hogline violation then they can replace the moved stones.
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| 03-04-15 02:24PM |
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Guest
Super Rockchucker
Registered: Feb 2005
Location: .
Posts: 1844 |
quote:
Originally posted by Three
When the handle fell off the Newfoundland rock on the opening week-end TSN showed the repari guy putting on a new handle. All the wires were exposed and it did not look like there was any shock or vibration dampening material anywhere. For those big weight throws it looked pretty fragile in my opinion as an engineer.
Not that you've mentioned it, on collision, what would the forces be on the the plastic handle the gizmo is attached to?
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| 03-04-15 02:43PM |
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AlanMacNeill
Super Rockchucker
Registered: Sep 2011
Location:
Posts: 1064 |
That would depend greatly on the shot thrown...
if we assume a worst case scenario of a high weight runback, then 100% of the momentum of a ~42 lb stone would be accelerated from zero to (speed of the runback attempt) in practically no time at all.
That's a fairly decent shock force...you can't calculate it without exact numbers...which, strangely, aren't easily found online...so the rest of this is assumption (and maybe bad assumption at that...)
If we assume a runback is moving at 25 mph and the momentum is transferred in 0.1 seconds (which I *suspect* to be high on the speed, but I also suspect it to be long on the time of energy transference, so those errors work to cancel each other out, to a degree), it would be 11.36G's of acceleration.
to give a sense of scale...if the shot speed is 15MPH in that same 0.1 seconds, you get a acceleration of 6.82G.
Subjecting a wired circuit to repetitive forces in the 6-10G range without shock buffering is almost certainly not a good thing.
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| 03-04-15 02:47PM |
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freezetothehack
Hitting Paint
Registered: Feb 2005
Location: New Brunswick
Posts: 199 |
quote:
Originally posted by Guest
Not that you've mentioned it, on collision, what would the forces be on the the plastic handle the gizmo is attached to?
Grade 11 physics: Newton 2nd and 3rd laws. A collision is an interaction between two objects that have made contact (usually) with each other. As in any interaction, a collision results in a force being applied to the two colliding objects. Newton's laws of motion govern such collisions.
Newton's third law of motion is naturally applied to collisions between two objects. In a collision between two objects, both objects experience forces that are equal in magnitude and opposite in direction. Such forces often cause one object to speed up (gain momentum) and the other object to slow down (lose momentum). According to Newton's third law, the forces on the two objects are equal in magnitude. While the forces are equal in magnitude and opposite in direction, the accelerations of the objects are not necessarily equal in magnitude. In accord with Newton's second law of motion, the acceleration of an object is dependent upon both force and mass. Thus, if the colliding objects have unequal mass, they will have unequal accelerations as a result of the contact force that results during the collision.
As luck would have it the math is easier in curling as it is assumed the two rocks are of equal mass.
esy as pie......or is that pi! 
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| 03-04-15 09:18PM |
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Par
Swing Artist
Registered: Feb 2006
Location: Canada
Posts: 407 |
speed of the stone
quote:
AlanMacNeill wrote:
If we assume a runback is moving at 25 mph ...
We don't have to assume anything about the speed of the rock. We know the distances and times, so we can obtain the speeds through simple calculations.
25 mph is a bit over 36 feet per second. At that speed, a stone would run from one hog line to the other (i.e. 72 feet) in less than 2 seconds. I don't know of anybody who can throw a rock that hard. Do you?
In competitive men's play, most peel weight shots run from hog to hog in about 7 seconds. That's about 10.2 feet per second, or roughly 7 mph.
Estimating the time required for the transfer of energy is more difficult. But if you run a video one frame at a time, you will see that when rocks collide, they are never in contact for more than one frame. From this we can gather that the time required for the energy transfer is less than 1/30 of a second.
So if you hit a stone on the nose with peel weight, its velocity will change by about 10.2 ft/sec, in less than 1/30 of a second. That's an acceleration of at least 300 ft/sec/sec, or roughly 10G...
... which is quite similar to your original estimate [!] but now we have something empirical to back it up.
And of course the shooter decelerates at the same rate. So the sensors in both stones are taking a beating. It's surprising that they ever work at all.
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