[TowerTalk] Your experience with rope capstan hoists or winches

[Grant Saviers]

?? 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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