[TowerTalk] Your experience with rope capstan hoists or winches
Steve Maki
lists at oakcom.org
Wed Sep 13 20:38:27 EDT 2017
Sorry, I read quickly and thought you were talking about capstans in
general. I've never been a sailor. Been on a few wild rides though, and
appreciated the skill involved.
There was one notable accident with a capstan which was mounted on a
swivel base, where the base lock pin failed, the capstan rotated, the
rope came off the drum, and a bad situation ensued. Swivel bases are
frowned upon. The attraction to them is that you can easily position the
capstan to be lined up properly. But it's easy to jockey a truck around.
Even better is to use a redirection block hanging off your ladder rack
so it doesn't matter which way the vehicle is positioned. This is all
assuming you are using a receiver hitch mounted capstan - the only way
to go BTW for regular tower work.
-Steve K8LX
On 9/13/2017 15:01 PM, Grant Saviers wrote:
> ?? I think I point out that self tailing (sailing) winches are a bad
> choice. And capstans are a good choice, particularly if they have
> reversing. Lot's of them in use as you mention.
>
> Do the problems I mention never happen on capstans? The original
> post question was basically "what can go wrong using a capstan?"
>
> Grant KZ1W
>
>
>
> On 9/13/2017 11:05 AM, Steve Maki wrote:
>> Grant,
>>
>> I can only say that if the sudden load movements and other
>> undesirable occurrences you describe were common happenings in the
>> tower industry using industry standard catheads, they would not be
>> industry standard equipment.
>>
>> The AB Chance catheads in particular were designed for the overhead
>> line industry, and have been used safely for decades for
>> installing pole transformers and HV lines.
>>
>> I wonder what type of capstan you were using while sailing. It
>> doesn't sound like the right gear for tower work.
>>
>> -Steve K8LX
>>
>> On 9/13/2017 12:28 PM, Grant Saviers wrote:
>>
>>> Years of sailing with winches large enough to pull 2+ tons taught
>>> me a few lessons about self tailing and hand tailing.
>>> Fortunately my or others screw ups resulted only in flailing
>>> sails, not the disaster that can happen with heavy vertical
>>> lifting. Although an out of control boom can be a lethal device
>>> as a friend was killed by one.
>>>
>>> I would never use a self tailing winch for overhead lifting.
>>> While the grip systems usually work, "usually" is not safe
>>> enough. They are also sensitive to the size, type of line and
>>> its condition. Then the release from the self tailing mechanism
>>> requires actions which often cause a jump in the load part of the
>>> line. The person releasing the line is in an awkward position to
>>> control the line and has fingers close to the drum.
>>>
>>> The person doing hand tailing needs to be thoughtful, alert,
>>> communicative, physically capable, and trained. Just as any
>>> other ground crew member. The functional problems I encountered
>>> with sailing winches were overruns, jams, and run-offs. An
>>> overrun is when a line gets under a turn nearer to the load
>>> (basically a half hitch knot). These can be very hard to safely
>>> or slightly release. A jam can happen when the turns get so tight
>>> together (or too many turns on the drum) they need hand massaging
>>> or a turn unwound to release and slip. Run-offs are when loops
>>> slip off the open end of the capstan and the tailing load jumps
>>> or becomes the total load. These are sometimes caused by the line
>>> handler not paying attention to the angle of the free line to the
>>> capstan, or jumps in the load.
>>>
>>> Is a spool drum winch better? - it depends. Different kinds of
>>> jams occur for winches of the type used on vehicles and tractors
>>> (experience with this), which btw are not overhead load rated. A
>>> crane winch spools wire rope with perfect lays to not have those
>>> problems. Like my HDX589's feeder to the spool. However,
>>> working with wire rope has a lot of downsides for handling and
>>> rigging. Not the way to go IMO for amateur radio sized towers
>>> and loads especially with the rope technology now available.
>>>
>>> The pro team that did my big tower used ropes and a capstan with
>>> power up/down. That capability with a good operator avoids the
>>> problems mentioned with lines on capstans. The loads were up to
>>> 350# antennas and controllable in less than a inch up/down. A
>>> convenient tie off on a cleat was on the winch mount and that was
>>> backed by a safety tie off. The tower sections weighed up to
>>> 1000# and went up with a crane. Although they had the gin pole
>>> and winch capacity for them the crane was faster, cheaper, and
>>> safer. For more than 25G towers and bigger than tribanders, I
>>> think these are the ways to go.
>>>
>>> Grant KZ1W
>>>
>>> On 9/12/2017 19:23 PM, Richard (Rick) Karlquist wrote:
>>>> I have been reading about how nice capstan winches are, but I
>>>> have no experience with them. They seem very dangerous since
>>>> the line comes loose and the load falls down in case the line
>>>> handler's attention wanders for a second. It seems especially
>>>> dangerous to be lowering a heavy load when the handler has to
>>>> pay out the line just fast enough, but not too fast. A foot
>>>> switch is suggested, but it doesn't work as a dead man safety.
>>>> The winch stops but the line still slips if not held back.
>>>>
>>>> Seems like an accident waiting to happen, like free climbing a
>>>> tower. Can someone with experience explain how these capstans
>>>> could possibly be safe?
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