Tag: lifting

This is Part 4 series by Senior Refrigeration Tech (and prolific writer) Jeremy Smith. Pay attention to this one folks, I know rigging and safe lifting practices may be boring to some of you, but it could very well save your back or your life.


Disclaimer

This article is written by a technician representing his real-world experiences and his advice for best practices. You MUST understand the particular application, weight of materials and load strength of every item you use. From struts to pulleys, to anchors, ladders, ropes etc.. HVAC School is NOT giving OSHA approved safety advice. Refer to your managers, safety professionals and OSHA guidelines first and foremost. Apply any and all of these practices at your own risk with the knowledge that we are trying to help keep you from hurting (or killing) yourself.


Unistrut is your friend

The idea for a site built, customizable, gantry struck me about 4 or 5 years ago. I started by throwing a piece of unistrut over a pair of plastic folding sawhorses on the roof. The whole shebang collapsed and I had to muscle the compressor plus the weight of the strut onto the roof but I was convinced that the idea was sound. From that simple setup, I’ve experimented with using ladders, fall protection fences, and various supports I built out of unistrut. I’ve had varying degrees of success and have settled on a design that works and can be modified to suit the conditions on a job site.

Let’s start with a solid base. Looking at the “T” shaped part laying on the roof, make each piece 6’ long at a minimum and and bolt them together with a proper brace. From that solid base, install an upright and the angle bracket, again using proper fittings. The angle brace should be 2 to 4 feet long depending on the height of the upright and the height of the upright depends on what your job requirements are. I’ve used them from 30” high to one that was almost 15 feet high. Now, build a second upright, same as the first one. Remember that crossbar I said we had to just “accept” that is was there? Now it’s time to put it there for real. Using a couple 90° brackets, bolt your cross piece to the two uprights and check for level..

This may seem complicated to build and maybe it is, but a part of this is laying out the basis for some other stuff later. These pictures are from a lifting job I did. 2 15 ton Copeland scrolls up through a roof hatch that came out on a mezzanine, trolley over and lowered to the main roof level.

Note in the last picture, the chainfall is connected to a device extending out of the unistrut. That’s a trolley and it makes moving those loads once you get them up onto the roof very easy. Let’s go back to our block and Tackle example earlier. The crossbar is a piece of unistrut and, instead of connecting your pulley and rope to the bar directly, connect it to this trolley. It is now very easy to lift that load right through the roof hatch, trolley it to one side or the other and lower it onto a cart or a dolly for transport across the roof surface.

A really nice, slick setup based on this that I use very frequently is for loading and unloading these out of your truck. My van is outfitted with commercial steel shelving. If yours isn’t, you may want to just skip this part. So, cut a piece of unistrut to fit across the top of those shelves. You should really have to work to get it in and out. Once it’s wedged in there, it isn’t going anywhere. Now, take a longer piece and support it across the rungs of a ladder parked 4-5’ off the back bumper. Bolt that piece to the crossbar you just installed and, using a trolley and a ¼ ton hoist, you can easily move a compressor in and out of your truck.

 


Now for the cautionary stuff. Unistrut is awesome. It’s strong and relatively light, but there are limitations to its strength. Please, before you build anything I’m suggesting here, know exactly how much your load weighs and exactly how much every single piece of your lifting equipment will support. I suggest a 2:1 safety factor if at all possible, so if you’re lifting a 100-pound load, make sure that everything in your lifting system is capable of handling twice that weight. Strength information about unistrut in its various applications can be found HERE As you use this reference, pay attention to point load ratings and span figures. As span increases, point load decreases. You DO NOT want that strut failing under a load so keep your loads within the limits of your equipment. If you look closely at the crossbar I use, you’ll see that it is thicker than normal 1 ⅝” unistrut. That’s a 2 ⅛” piece and is much stronger. If you’re going to do heavier lifts, you really need a heavier crossbar like that. Be aware, the engineering specs and the catalog are very dry, boring reading but take the time to learn and know what your lifting gear will do before you have to really stress it and potentially injure yourself or someone else. Remember, the point of this is to lift and move things safely…

— Jeremy
Shopping list
Genuine Unistrut P2950-EG 4 Wheel Trolley Assembly for use with P1000, P1001, P5000, P5001, P5500, P5501 and All 1-5/8″ or Taller Strut Channel

Genuine Unistrut P1325-EG 4 Hole 90 Degree Angle Connector Bracket for All 1-5/8″ Strut Channel

Genuine Unistrut P1031-EG 4 Hole “T” Shaped Connector Bracket for All 1-5/8″ Strut Channel

45° inside brackets for unistrut

This is Part 3 series by Senior Refrigeration Tech (and prolific writer) Jeremy Smith. Pay attention to this one folks, I know rigging and safe lifting practices may be boring to some of you, but it could very well save your back or your life.


Disclaimer

This article is written by a technician representing his real-world experiences and his advice for best practices. You MUST understand the particular application, weight of materials and load strength of every item you use. From struts, to pulleys, to anchors, ladders, ropes etc.. HVAC School is NOT giving OSHA approved safety advice. Refer to your managers, safety professionals and OSHA guidelines first and foremost. Apply any and all of these practices at your own risk with the knowledge that we are trying to help keep you from hurting (or killing) yourself.


Complex block and Tackle systems

Now that we have a basic understanding of how to handle ropes, tie knots and rig a basic pulley system, we’re ready to dive into more complicated systems. I reserve these for buildings that have a roof hatch so that I can setup a gantry over the hatch. I haven’t yet figured out a system to extend a beam over the edge of a building, but I’m working on it. I’ll go into the basics of how I build and what I build in the next section. For now, let’s just accept as a given that we have a solid beam installed over the hatch opening to connect ropes
and pulleys to.

For jobs like this, I keep a double pulley on the truck. Threading or ‘reeving’ these takes more time and is more complicated but the reduction in effort is worth it. Start by fixing your single pulley to the overhead beam and connecting the double one to a light “load” like a wrench or something similar. Tie one end of the rope to our overhead beam. Start threading by running the other end through one side of the double pulley then through the single, through the other side of the double. Now, you should have a nice mess of rope. Lower that weighted double pulley to the spot where the load is and secure the free end of the rope with a clove hitch just to keep it from falling and to keep a tiny amount of tension on the system.

The setup shown here was used to hoist a 15 hp blower motor onto the roof. Motor weight was something like 145# With 4 lines supporting the load, the effort to hoist that motor was less than
40#.

I like to stand on the roof while hoisting, so I make it a point when threading pulleys to wind up with the pull end of the rope going up. This also has the advantage of using every line to support the load and obtaining maximum effort reduction.

As before, connect to the load and hoist it slightly. Check for good balance, twisted ropes and crossed lines. Make any corrections and hoist away. Since we’re hoisting to an overhead beam, there won’t be any need to take 100% of the load at any time, so this method is much safer and, when we dig into the gantry build, we’ll find a great way to manage the load once it’s at the top of the lift. As the loads get heavier, you’ll be using heavier and heavier duty hardware to attach to them. Eye bolts, shackles and chains are the rule here.

— Jeremy

Shopping list…
Stanley National Hardware 3214BC 1-1/2″ Zinc Plated Fixed Double Pulley

Crosby 1018393 Carbon Steel G-209 Screw Pin Anchor Shackle, Galvanized, 3/4 Ton Working
Load Limit, 5/16″ Size

This is Part 2 series by Senior Refrigeration Tech (and prolific writer) Jeremy Smith. Pay attention to this one folks, I know rigging and safe lifting practices may be boring to some of you, but it could very well save your back or your life.


Disclaimer

This article is written by a technician representing his real-world experiences and his advice for best practices. You MUST understand the particular application, weight of materials and load strength of every item you use. From struts to pulleys, to anchors, ladders, ropes etc.. HVAC School is NOT giving OSHA approved safety advice. Refer to your managers, safety professionals and OSHA guidelines first and foremost. Apply any and all of these practices at your own risk with the knowledge that we are trying to help keep you from hurting (or killing) yourself.


Simple pulley systems

Let’s get into the meat of lifting and moving heavier loads…

One thing that I use a LOT is a basic pulley. Simply put, when using a pulley or a system of pulleys called a Block and Tackle, the amount of force required to lift a load is the total weight divided by the number of lines supporting the load. An overhead pulley system doesn’t reduce lifting force at all. It does nothing more than redirect the force applied. Since there is only one line supporting the load, there is no reduction in force required to lift the load.

A pulley connected to the load with one line tied off and pulling force exerted on the other end of the rope will cut the force required in half for lifting a load. Here, with 2 lines supporting the load, the force or effort required to lift the load is cut in half.

 

In practice, I limit this to loads of 50-100 pounds or so because at the end of the lift, you will be lifting 100% of the weight. For your first couple lifts, try to stay on the lower end of these weights until you build confidence in your techniques. We’ll get into more complicated systems with more pulleys and lines in a later section.

Start by tying off one end of the rope to something secure. This is your anchor point. Best case scenario, there is something they’re purpose-built to anchor to. Worst case scenario, I’ve actually tied a loop around the entire curb assembly of a rooftop unit.

Remember, use good knots. The ONLY knot that I trust in this situation is a bowline. Now that we’ve got our rope anchored, slide the pulley onto the rope and lower that pulley to your load. Tie the other end, the lifting end, of the rope off to something, anything really. A clove hitch is quick and easy here. All we’re doing is keeping the rope in place so it doesn’t fall. To connect the pulley to the load, I like to use a climbing carabiner with a screw lock. Cheap carabiners that you can get at most home improvement Warehouse stores are NOT suitable here. If all they do is bend under the load, count yourself lucky.

If there is a lifting eye or provision to install one on the load, use it and be sure to lock the eye bolt in place with the included nut, otherwise, the load can unscrew itself from the bolt and fall. That is going to be the best and safest place to connect your pulley to the load. Now, back up to the roof and take a couple seconds to straighten out the ropes. Get any twists out of the system and lift the load a short distance off the ground. Check everything. Is your anchor solid? Are you comfortable with the load? If everything is good and you’re comfortable with the lift, then continue pulling the load up to the roof edge.

Remember when I said to limit the weight? Now you’ll see why. You’ve got the load almost there…. You’re going to have to squat to the load, grab it and haul it over the roof edge. Yeah, it sucks but not as bad as hauling the whole load all the way up the side of the building. This is where a carabiner is nice because that big metal loop gives you a solid handle to grab
and hang on to.

— Jeremy

P.S. – Today’s Shopping list

Stanley National Hardware 3213BC 1-1/2″ Zinc Plated Fixed Single Pulley

Mad Rock Ultra Tech Screw Carabiner

 

This is ANOTHER series by Senior Refrigeration Tech (and prolific writer) Jeremy Smith. Pay attention to this one folks, I know rigging and safe lifting practices may be boring to some of you, but it could very well save your back or your life.


Disclaimer

This article is written by a technician representing his real world experiences and his advice for best practices. You MUST understand the particular application, weight of materials and load strength of every item you use. From struts, to pulleys, to anchors, ladders, ropes etc.. HVAC School is NOT giving OSHA approved safety advice. Refer to your managers, safety professionals and OSHA guidelines first and foremost. Apply any and all of these practices at your own risk with the knowledge that we are trying to help keep you from hurting (or killing) yourself.


I know, I know… everyone is super strong and nobody needs any help lifting those big, heavy compressors and motors. At least that’s what a guy could think if he just reads the HVAC pages
online.

Reality check. If you’re lifting anything over 50 pounds and are not using a mechanical device to do it, you’re risking serious injury. I speak from experience here. In 2016, I spent 16 weeks off of work progressing from Chiropractic care to physical therapy and ultimately had to have surgery to repair a herniated disc. The injury resulted from a twisting motion when a 200lb compressor we were throwing into a scrap bin went sideways and started to fall on me. I caught it but I didn’t avoid a painful injury…

Hopefully, I’ll be able to share more than a few tips, tricks and techniques to help you work more safely and more effectively and inspire you to learn more about this subject. By no means should this be taken as a comprehensive treatment of the subject of lifting and rigging, but just a primer with some cautions and warnings and the advice to go slow and always, ALWAYS double check yourself **before you wreck yourself** (**Added by Bryan in editing… because he’s a child)

Let’s lay down some baseline rules. Not to be “preachy crossfit guy” but keep your core strong. Sometimes, you just have to gut it out and move a heavy thing. Those core muscles are what prevent injury when your body goes outside of your normal range of motion and, if they aren’t strong, they can’t support your spine and skeletal system and that’s when you get injured.

Also, when you just have to lift using body strength, use proper techniques. We all know the words “Lift with your legs, not your back” but how many of us actually DO? I can tell you for 100% certain that any time I’m moving to lift something, I’m using proper techniques whether it’s a refrigerant drum or a screwdriver I dropped. Now get down and give me 20 squats!

As we get into the application of ropes and pulley systems, we will be tying knots. Knot tying can be a very involved topic but you can do everything were going to be doing with the bowline and the clove hitch. If you can’t tie either of those knots, here are links to simple videos that illustrate how to..

BOWLINE

CLOVE HITCH

If you attempt any of these techniques with inferior knots, you run a very real chance of losing control of that load and injuring yourself or someone else and damaging that expensive part.
Another thing to take a bit of time to learn about is basic rope care. A knotted, twisted rope isn’t as easy to set up and you’ll waste time dealing with twists, knots and tangles. Learn to coil and stow your rope well and this stuff will be a lot easier.

A quick note on rope. Buy good rope. Avoid the 3 strand twisted rope. It’s stretchy and the ends unravel and are difficult to manage. What you want is called Kernmantle rope. This is the type of rope that has a kind of braided “sheath” over inner fibers. It’s stronger, doesn’t stretch and it rides much easier through pulleys. Burn the ends well to prevent them from getting out of control.

One final note. Wear a decent pair of relatively snug fitting gloves while hoisting and lowering loads with a rope. If that rope starts to slide, the burns you will get on your hands take a long time to heal.

Now, basics covered, we can move on to actually lifting things.

— Jeremy

P.S. – Here is a good rope ROTHCO UTILITY ROPE 3/8” 100 FT / OLIVE DRAB

This is Part 5 series by Senior Refrigeration Tech (and prolific writer) Jeremy Smith. Pay attention to this one folks, I know rigging and safe lifting practices may be boring to some of you, but it could very well save your back or your life.


Disclaimer

This article is written by a technician representing his real world experiences and his advice for best practices. You MUST understand the particular application, weight of materials and load strength of every item you use. From struts, to pulleys, to anchors, ladders, ropes etc.. HVAC School is NOT giving OSHA approved safety advice. Refer to your managers, safety professionals and OSHA guidelines first and foremost. Apply any and all of these practices at your own risk with the knowledge that we are trying to help keep you from hurting (or killing) yourself.


Heavy stuff and getting creative, safely

Alright, we’ve got the basics down. Knots are no problem, rigging up a 100# compressor is a piece of cake and the boss has started to send you on those heavy lifting jobs because you can confidently do them easier, faster and more safely than your coworkers. Then he drops the bomb on you…. Next week, he needs you to change out another compressor. The catch?? It’s a 25 HP Copeland 4D model. A big girl. A compressor like that weighs about 450 pounds. This isn’t the time for ropes and pulleys, we need to get some
serious hardware out.

Enter chain hoists and chainfalls.

Now, if it needs to go onto a roof, DO NOT use these methods unless there is absolutely no alternative. I’ve used them on second floor indoor lifts, but if you can use a crane, USE A CRANE. I worked to develop these techniques to fill the gap between compressors like the big 4D where a crane isn’t a question and something like a 9000btuh mini split compressor that doesn’t weigh but 20 pounds or so and to help in the final positioning of that machine.

Now, we can lift some stuff…

Not so fast… We still have to connect to it. Up until now, the forces involved haven’t been enough to bend or break lifting hardware but, with loads weighing hundreds of pounds and the real possibility of putting angular stress on components, we need to talk about lifting eyes, shackles, chains, straps and some other fun stuff.

Lifting eyes are exactly that. They are designed to have force applied to them in a certain way and, if force is applied in the wrong direction, the bolt can bend or break.. Force is ideally exerted straight up and down. If that force needs to be applied at an angle, you need to back up a step and slow down. Can you figure a better way to do the job? Is there a better way to hook up the load to avoid stressing the bolt in that direction? If not, there are 2 basic rules for using that eyebolt with angular force applied.

#1. Keep the force applied in the plane of the eye. Pulling sideways on the eye will bend it.
#2. Don’t let the force angle go past 45°

Before we move on from eyebolts, a couple more things. There is a difference between a plain eye bolt and a shouldered eye bolt. Use the shouldered eye bolt. It’s stronger and is designed to be used for lifting, especially if you need to put any angular force on it. Also, when installing an eye bolt, it needs to be tightened properly and of proper length. If the eye bolt is sticking way out of the threads for it, that allow the applied force to be able to bend that bolt much more easily.

Chains vs. Straps

Frequently, I find myself setting up complicated lifts that require multiple anchor points. For making anchors, particularly around structural steel or unit framework, I prefer to use short lengths of chain and a shackles. The length of chain tends to be almost self centering once a little force is applied to it and the shackle is a good anchor for whatever machine I’m using to lift or pull with. Straps are handy to have around but, as my skills in this area have developed, I’ve come to find that most lifting straps have a degree of stretch to them which can make precise positioning difficult and, when I’ve got a 600# motor in the air and I’m trying to lift it a fraction of an inch, just to clear a mounting bolt or to slide a shim in place, I don’t want any variables that I can’t control. Chain doesn’t stretch. It’s just one less thing to worry about while that load is in the air.
Now, we can start getting to work. I carry 2 or 3 ¼ ton lever chain hoists on the truck and have a ¾ ton lever hoist and a 1 ton chain fall easily accessible for larger lifts. Some guys use a
cable puller or a come along to lift with, and I did so for a lot of years, but those types of devices aren’t ideal for that purpose. This is where things kind of leave the realm of what can be taught or explained. I can’t necessarily design or explain how to build a gantry or lifting system to move a compressor in a place that I’ve never seen. Look around. Use structural steel, unit framing, unistrut, and threaded rod to create a custom lifting gantry. Here are some examples of site built rigs I’ve used to change out compressors.

 

 

 

Note that the unistrut is bolted to the top of the ladder to prevent falling. Creativity and stability is key, here. Go slowly and be very careful lifting loads. Very often, you don’t have to lift it many feet in the air, but only a fraction of an inch to get it to clear whatever is holding it then, with the trolley, it will slide easily out of place and back in again…

Getting Creative

A challenge that was posed to me was to setup a rigging system to take a 30HP compressor from ground level to the second floor up a flight of stairs without touching a step. Someone in the past had made something like a pair of skis out of unistrut and dragged the compressor up the steps using that setup. This broke the edges off of several steps and created trip hazards. Take a couple minutes and consider this challenge. Come up with your plan.

Now, here is how I did it.

At the top of the staircase, I had a piece of unistrut wedged into the structural steel. A solid anchor point. I went to the ceiling above the bottom of the stairs and installed another anchor
point. At the bottom of the stairs, I installed a small anchor point away from the bottom of the steps.

At the top of the stairs, I setup a 1 ton chainfall. Above the bottom of the stairs, I setup a come along (I know I said they aren’t ideal. They aren’t. It’s just what I had to work with) and I setup a small chain hoist between the bottom of the steps and the anchor. In practice, each hoist connected to the load. Start by pulling the load back, away from the steps. Now, start taking up the weight with the hoist above the base of the steps until it is high enough to clear the steps. Let out the small hoist and disconnect it. Now, start swinging the load up the staircase using the chainfall, adjusting the height as necessary with the other hoist. This basic technique is one that I use frequently. I’ve called it “the trapeze” or “pick and swing” and, to be honest, I don’t know if it has a formal name, but it’s a very useful lifting technique to have in your toolbox. A variant on this idea is using one hoist to primarily lift the load and two hoists to kind of steer the load into place.

Thanks for sticking with me through this. I hope that you’ll take these techniques, adapt and apply them to your own needs and hopefully you’ve found something in this to help to prevent
injury and to make those bigger jobs a little easier.

— Jeremy

Shopping list

Roughneck Manual Lever Chain Hoist – 1/4-Ton Capacity, 12in. Head Room

Lever Block Chain Hoist 3/4 Ton 1650 lbs Capacity, 5′ Lift – Tec-union

1 ton chainfall

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