Wire Rope Clamp Saga


http://forums.justoldtrucks.com/Topic21104.aspx
Print Topic | Close Window

By bshoesey - 10 Years Ago

Don't Saddle a Dead Horse- The Wire Rope Clamp SagaThis is a featured page


This is going to be a combination of "technical info-kind of", that includes the discovery of plow spools for lifting the plow and the failure of the wire rope doing the lifting. At a visit to TENCO in Lakevillle NY quite a number on years ago, I noticed that they were using a spool affair to lift the plows they installed. I asked about the purpose of that and was told that the spool/cable combination automatically levels the plow as you raise and lower it, minimizing the chance of wearing one corner of the blades prematurely. That was a savings back then. In todays money, a plow blade change, including carbide insert blades, cover blade, shoes and hardware is quite the expensive proposition. There is an added expense in the downtime for a plow truck while changing blades only worn out on one side.
I was doing spreader calibration at my old job 35 years ago. One step was to adjust and mark the lift chains to pick the plows up evenly and extend blade wear. This was generally good until the first time the drivers took the plow off. It was always a crap shoot that the chains would be hooked up the same. As Equipment Manager I always looked at the plows when they pulled into the yard to look for bad blade wear and give the driver a refresher talk and reset the chains. This problem was particularly evident with our reversible plows. I liked the idea and asked about purchasing some spools from TENCO to try. They declined the sale, claiming they were just as well made in our welding shop. We tried a few and they worked terrific. Every time you set the plow down and the cable goes a little slack, it re-centers on the lift stroke and picks the plow up perfectly square. No early blade failure from improperly adjusted lift chains. This worked well with both one-way and reversible plows. Our reversible plow trucks were dedicated driving lane/passing lane which made it easier to get it just right. They took some fussing, believe me. Not long after we started using them we noticed wire rope failure about 8-12" above the clamps. The first response was to just change the wire rope, but that didn't cure the problem. My District Equipment Manager Walt Gibbs was at the shop one day and we were looking over a failed wire rope and I was wondering out loud what the problem was. He looked at the set up and said "don't saddle a dead horse". I said OK, what does that mean. The proper way to install wire rope clamps is to put the u-bolt around the cut end (dead horse) and to "saddle" the long end. The following scan is from a Frink power wing drawing illustrating what I'm talking about.

Don't Saddle a Dead Horse- The Wire Rope Clamp Saga - walter linn oshkosh fwdRig on 50.5mm haul rope

As you see here, the "saddle" is over the long end. The rest of the story here is that I started having a standard length cable with swedged ends on it. This wire rope was much more flexible than what we had in stock. This allowed the rope to fit the spool a little better. Another advantage was that with a standard length you only stocked one size. We made up the additional length with chain to uncomplicate things. I can say with much confidence that any factory drawing of wire rope and clamps will show this to be the correct way to do it. The actual percentage of failure doing it the other way remains to be seen. This episode of "technical info-kind of" is a reprise of the same info I added to the old Oshkosh Owners site (RIP) a number of years ago. The site is still out there but I haven't seen any activity on it , at least since the last time I checked.

I did a very basic drawing of the spool itself. The tube section needs to be @10" diameter to accomodate the wire rope wrapping around it. Well casing of about that size would work well. It does need to be heavy walled. I highly recommend this to any professional plowers who understand the financial drain of premature blade failure as I described it here.


Don't Saddle a Dead Horse- The Wire Rope Clamp Saga - walter linn oshkosh fwd

The wire rope needs to be threaded thru the top, one loop around the bottom of the spool and out the opposite side. This setup also provides excellent stability in the raised postion as the wire rope is clamped to the spool by the weight of the plow. I hope this explains things well enough and maybe even helps someone out there. I suppose you could contact TENCO in Lakeville, NY to buy one if you didn't want to bother making one. Bshoesey

A little more info on wire rope clips. There is also a better clip that crosby developed about 25 years ago called the crosby fist grip. You cant put it on backwards. The 2 pieces are the same and they have a 99% efficiency factor. Also once you get them tight they stay that way as opposed to a regular clip that tends to crimp the cable and therefor be loose. Plowman

Don't Saddle a Dead Horse- The Wire Rope Clamp Saga - walter linn oshkosh fwd