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Here are some of our most frequently asked questions.
1.) Can I use my Hogg Davis puller for small cables
and fibre-optics?"
Yes. Even though our pullers can create up to 20,000 or 40,000 pounds of
line pull, they can only create that if there is that much resistance to
the pull. If there is only a 100 pounds resistance, our puller only creates
enough to overcome that resistance. For fibre optic cable, we suggest you
utilize a capstan on the auxiliary drive shaft rather than the main reel
drive. We suggest the capstan marketed by GMP that utilizes a slip clutch
to protect the fibre-optic cable should the resistance exceed the cable
strength.
2.) The low oil pressure warning light comes on when the engine is at idle, do I have an oil pressure problem."
Probably not. The oil pressure sender unit requires 5psi to shut the warning
light off. At idle, the Wisconsin VH4D engine produces less than psi, yet
it is operating correctly. You should be concerned about oil pressure if
the light comes on when the engine is running at medium to big rpm's.
3.) If the cylinder that raises and lowers the idler wheel
on the Hydra 985 is double acting, what are the big springs for?
The torsion springs that operate between the lower "A" frame of the idler wheel
and the front frame member, are designed as a redundant safety feature. They are
there to insure that the idler wheel can never "bleed" down while the trailer
is in transit. The springs are designed to hold the entire weight of the idler
wheel in position, even if the cylinder was totally disconnected from the system.
The only way the idler wheel can come down is under power.
4.) How do I know I have enough pressure against the reel with the drive rollers?
When you bring the drive rollers against the reel flanges, make sure all rollers are against the flange and the pressure is just enough to show visual indentation of the roller material. This is enough pressure to safely transport the reel (remember, the power unit and drive -rollers act as safety to guard against the reel shifting forward in the event of a sudden stop.) This is also enough pressure to initially turn the reel at the job site. If the rollers slip during the pull, apply just enough additional pressure to get the reel turning again. Repeat additional pressure as required when the rollers slip. In this manner you only use the pressure required to complete the pull. This method will save lots of wear and tear on the machine.
5.) Why don't you put a pressure gauge on the machine to tell me how much pressure is against the reel?
There is no practical way to measure the pressure between the drive rollers and the reel flanges. A pressure gauge on the power unit cylinder is susceptible to false readings and therefore can become a safety problem. Any readings at the cylinder or extrapolations of such readings would vary from pull to pull depending on the cleanliness of the slide rails, the lubrication to the rails, the internal integrity of the cylinder and other factors that make it totally unreliable. The best way to determine the pressure is ratio of the drive roller material against the flanges.
6.) Why don't you use double acting cylinders in the reel lifting mechanism?"
Since our lifting cylinders work in the vertical position, we allow gravity to work for us. This saves a lot of damage to paved surfaces, too. With our system, when the reel makes contact with the ground, it stops. With double acting cylinders an operator could inadvertently push the reel through the blacktop. It's happened plenty of times. On cold days it may be necessary to run the unit to warm the hydraulic fluid to make lowering easier. You can also turn the engine off, which eliminates some hydraulic back pressure and allows the lifting mechanism to come down easier.
7.) There are no hydraulic "load locks" on the lifting cylinders,
why?
We believe firmly in the principal of transferring the load to the frame of the trailer. This is accomplished by allowing the lifting mechanism to settle onto mechanical locks, which are mounted to the frame. This removes all strain from the hydraulic system. A loaded reel bouncing down the road can exert tremendous shock loads to a hydraulic system. We feel steel to steel mechanical transfer of the load to the frame is much safer and reliable.
8.) Why don't you offer electric pendant remote control
on your cable pullers?
The primary reason we do not offer remote control is safety. The secondary
reason is maintenance. Lets tall about the safety aspect. Most people automatically
equate remote control as safer. This is not necessarily so. Our pullers
are designed to be operated from specific operator positions at either the
front or rear of the unit. If the operator stays at those positions, he
can see everything he needs to see and control everything he needs to control
to perform his job correctly. And at those positions, he is not likely to
put himself" in harms way." With a remote pendant, the operator would have
the ability to "stray" into a position that might put him in the "bite of
the line." We feel cable pulling machinery has to be operated "hands-on"
to be safe. Our second concern, though less important an safety, is maintenance.
All forms of remote control, be they hard wired, radio or infrared, require
substantial maintenance. Each connection is another potential failure point.
Elimination of such connections alienates those potential failures.
9.) I've used the Hogg Davis puller fox underground pulling but never overhead. Now I've got an overhead job. Will it do it?"
YES! Long before we earned our reputation for underground pulling, our machines were pulling both power and telephone cables overhead. They work great for reconductoring, removal or new installation, Your standard rigging procedures that you currently use for overhead will probably work just fine. Set the machine up the same as you would any type of puller. Always try to set for longest lead angle as possible. This helps relieve the strain on the crossarm or pole nearest the puller.
10.) I don't seem to be getting enough pulling power. Is
there any way to increase the power?
Assuming you're already in the lowest gear range and the engine is running
at optimum horsepower rpm (1800-2000), the reel you are using is probably
the culprit. Our machines, like all cable pullers, are nothing more than
huge winches on a trailer frame. Maximum power, like a winch, is at the
first wrap on the drum. With a friction drive puller, like ours, the power
is applied at the outside diameter of the reel, rather than at the shaft.
Therefore, the greater the outside diameter in relationship to the core
diameter, the greater the leverage more power. Our pull ratings are established
using our 805O BreakAway Reel. This reel has and outside diameter of 80"
and a core diameter of 24". If you subtract the radii (40 minus 12 = 28)
you determine you have a "lever" 28" long that you are utilizing. Try to
use reels that have the longest "lever" to get the most power. Also, try
to use reels with wide flanges, This provides more friction surface against
the rollers for optimum power.
11.) My boss says that once you start a pull you can't stop because you'll never get the cable started again. Is that true?"
Your boss has probably had a bad experience at one time or another when that was true. However, in our experience, that is not the rule. This situation usually only occurs in removing underground cables. Depending on how long the cable has been in the duct, the type of cable, type of sheath, type of duct and its condition all play a part in the ability to get the cable out of the ground. The greatest amount of force required is usually at the beginning of the pull. Once the cable breaks loose, the amount of force required to move the cable drops way off. It's much like pushing a car. The greatest force is getting it rolling and from there it gets easier. From a time efficiency standpoint it makes sense to keep going once you've got it started. However, if you must stop for safety or rigging problems, you shouldn't have any problem restarting the pull.
12.) Some jobs we do go real easy and then it seems the next job is really tough. But the jobs have the same footage of cable, what gives?
Since I am not on your particular job I can't give you a definitive answer. However, there are many aspects that effect pulling ease besides the amount of cable. Some of those are cable type, cable sheath, duct type and condition, number of sweeps and their angles in the duct and duct cleanliness. A duct that has flooded many times over the years and filled with silt is always a tough pull. Electrolysis and lead sheath cables create a situation where a cable can virtually weld itself to the duct. A duct that has cracked or settled can create tough pulls. The easy ones are always nice, but a lot of things can be going on down below that will make it tough.
13.) When we're wrecking cable we use a chain to grab the cable and get it started. Then we reverse the machine to take the chain off the reel, then attach the cable to the reel to finish the pull. Any ideas for eliminating this step?"
Assuming this cable is going to the scrapper, I've got two suggestions.
The first is a method that comes from an old telephone construction supervisor
friend of ours, and everybody we told it to liked it. When it comes time
to put new cables on your truck winches ox cranes, don't throw away the
old cable-not yet, anyway. Cut it up into lengths long enough to take a
couple wraps around the reel and reach down in the vault to duct level.
Say, 40-50 feet. Then swage about a 3 foot eye in one end. Coil them up
and throw them on the truck or in the tool crib. Take a coil to the job
for each cable you have to remove. Figure 8 the eye around the end of the
conductor, getting as many "8"s as you can, shoving the eye up the cable
and as far into the duct as you can. Take the other end to the reel. Now
everything on the reel is scrap, including the old winch line. No more stopping,
no more rescuing chains. The Figure 8 bites the cable well and should give
you a good pull. The second recommendation is the use of one other Hogg
Davis Breakaway reels for the job. You won't tear up returnable Cable Company
reels and they're designed for optimum pulling power.
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