You have been dispatched to use your winches to lower a 40-yard roll-off dumpster into driveway that has a tree line down both sides creating a canopy over it preventing the roll-off truck from unloading it at the bottom without damaging the trees. The truck you are in is a 16 ton wrecker equipped with dual 15,000 lbs winches that have 150 feet of 1/2 steel core wire rope.
The roll-off dumpster has rollers on all four corners which will allow it to roll down the concrete driveway. The curb weight of the empty dumpster is 6,650 lbs. The driveway is sloped towards the house. The layout of the driveway is straight from roadway with it ending right next to the garage. The garage door is to the right of the driveway. The length of the driveway to the spot where the contractor wants the dumpster is 100 foot with the first 40 feet being flat and level which will allow the roll off company to unload the dumpster on the flat part of the driveway. The rest of the driveway is at a 15° until it levels off at the bottom of the driveway. The contractor has swept the driveway to remove any debris that was on it.
Once the roll-off is unloaded, it is chocked in place with two rubber chock blocks. After performing your survey, you note that there is room in front of the dumpster to position your truck directly in front of it. The front of the dumpster has two attachment points designed to have a two-legged bridle attached to for such instances.
On the back of the dumpster, the company has painted its Name, dumpster number, empty weight as well as a list of items not allowed in it. The empty weight is 6,500 lbs.
1/2 inch steel wire rope WLL 7,490 lbs
1/2 inch Grade 100 12 foot Two leg bridle WLL 26,000 lbs @ 60°
With the information, you were able to gather during your survey, answer the following questions.
1. What is the resistance of the dumpster?
2. Will the wire rope be within its working load limit if used as a single line?