OLDS=Overhead Lowering Device System Probably fifteen years ago I found a friction tool that I thought would work as a lowering device. Take a look: http://bmsrescue.com/blayspl.html Read the paper on the spool: http://bmsrescue.com/bspaper.html Carroll has other papers that should be read too. After talking with Carroll about the application as a rigging device he agreed that it should work very well. After getting the spool it didn't take long for my crew to work out a smooth system for using the friction in the tree. I cam up with the name OLDS because we had a whole set of gear that we used to make the system work. It was easier to name the gear set instead of listing the gear that we needed. The OLDS was setup in a place like any other lowering point would be chosen. Since we used an eye/eye flat webbing sling we could choke around a smooth limb or trunk and not rely on using branch unions. Depending on the rigging loads a strong steel biner or shackle was used. Most of the time we used the OLDS for lowering limb wood and small slam-dunk chunks so a biner was sufficient. The rope we used was New England half-inch double braid. Very rarely we would shift to 9/16. We found that if we rigged the rope with two full wraps not the potential three we had plenty of friction. The rope would enter the spool next to one cheek plate then spiral around and exit next to the opposite cheek. The middle 'gate' between the pins wasn't used. The rope had an eye on one end and not the other. We generally clipped a biner in the one end. When it came time to rig the climber would use slings for knotless rigging. Both ends of the rope were used, more later. I'll lay out the step-by-step OLDS process: Set OLDS as rigging point Climb to tie off point. Use slings or knots/hitches to attach the branches Groundie would make the rope fast and get ready to belay the load. Occasionally a partial wrap was made. The wrap would be taken against the smooth bark of the upper canopy when possible. If not, around the lower trunk or another tree. This was just as a back up for larger loads. A 'Belt and Braces' approach. After the cut was made and the load held by the spool two different lowering procedures could be used. 1-The groundie lowers the load and controls the friction of the rope 2-The climber moves over and becomes the belayer. This frees up the groundie to move around and use both hands. Also, a real key for efficiency is that the bitter end of the rope can now be moved out of the drop zone. The end would never be near the brush or need to be cleared. Since the bitter end was moveable the LZ becomes much neater. The climber could pull up the bitter end to get it completely out of the way. Doing this would setup the next lower too. OK...the climber is now belaying the load...the load hits the ground. The groundies take over and process the brush for moving to the chipper. As that's going on the climber takes the other end of the rope and starts to setup the next cut. Using both ends of the rope means that the climber doesn't get those mini breaks but they do get out of the tree quicker so it pays off. Having the climber rig and belay is almost like having two crews working at once. It was rare that the groundies had to wait for the climber to set the next lower. Since a portion of the load is dissipated through friction on the spool the load on the rigging point varies. This is very similar to the way that the load on an SRT TIP varies depending on the amount of friction. See the attached drawing. Single Jack made the illustration and it is the best illustration of how TIP loads can change when friction is accounted for. The spool can be setup for remote removal too. Think of how many ways that a climbing FC can be rigged. The Rope Guide variations work here too. I’ll leave this portion of creativity to you to figure out. Most times the job would lead the climber back to the spool so we rarely setup remote retrievals. When we got the OLDS fine-tuned I asked my crew how much work the setup saved. The conclusion was that it eliminated between half and one full person on the crew. Since the climber is working more this frees up the ground crew to just work the ground. Virtually eliminating snaggled ropes and the load crossing the down rope saves time. The workflow was smooth with few stops. Previously, using friction devices on the ground meant a more herky-jerky workflow. The beauty of using the spool is in the design of the corner radiuses. When loaded the radiused corners add more surface area contact like the tube on a bollard. Also, the rope snubs down onto the flats. But, when the rope is NOT under tension the rope springs up off the flats and rides on the smooth, large, radiuses. The climber would yard the rope up and it would feel almost like coming up through a pulley. There is VERY little friction with no load. We found that using half-inch rope was a good base to design safe working loads in relationship to friction. Larger ropes [9/16”] could be used but the added friction on the cheeks and pins in the spool made it harder to yard up. The weight of the rope got to be a bit much. In the end we just made another cut to keep things smooth. Since the rigging rope is captured between the swivel cheeks there is no chance of having the rope jump out or have it criss cross like when using a bollard in the tree. Most other friction devices but nasty hockles in the rigging rope. Using the spool, even with the same end a few times, we rarely, almost never, had hockles. Since the most efficient system was to use alternate ends hockling became a thing of the past. For such a compact and simple tool the Belay Spool had as much impact on rigging as going from natural fiber ropes to synthetics. Have at it!