common crane accidents

Common Causes of Crane Accidents and How to Prevent Them

Cranes are a critical part of countless construction and industrial projects, providing support and stability in a wide range of applications. With the ability to increase productivity and reduce overall expenses, the invention and implementation of the modern crane has revolutionized the possibilities available in dozens of industries.

However, as with all heavy machinery, inattention to detail and improper safety practices can result in tragic implications. From 1992 to 2006, 307 crane accidents in construction sites led to 323 total deaths – an average of 22 per year. Further, according to the research conducted by the Bureau of Labor Statistics, over the ten years between 1997 and 2006, cranes contributed to a total of 818 fatalities in workplaces of all kinds.

The danger involved in improper crane operation cannot be understated, but increased awareness can make a difference. By reviewing and understanding common causes of crane accidents as well as prevention strategies, it’s possible to reduce the likelihood of injury and death.

Crane Tipping Due to Improper Outrigger Use

Any tipping incident can be extremely dangerous for both the crane operator and the other workers in the area surrounding a crane. While thankfully rare, most crane tipping accidents are due to improper outrigger use. This can occur in several different ways but is largely related to unsuitable ground conditions, including depressions, voids, excavations, and uneven grading. When the outrigger pad is positioned on unlevel, wet, or otherwise unstable surfaces, you risk an inability to control crane positioning.

Instead of assuming any area is good enough, use common sense and attention to detail. Fully inspect every area, analyze ground conditions, and manage deflection levels as best as possible. If forced to work in inopportune settings, take extra precautions to improve the load bearing capacity using additional supporting materials.

Dropped Loads Due to Improper Rigging

Cranes are designed to carry heavy, awkward, and oversized items, but when rigging isn’t up to the task, you risk dropping a load and endangering both property and human life. Failed rigging often arises from human error, ranging from improper adherence to procedure to utilizing broken or failing parts. One wrong move can lead a load to slide or fall in a catastrophic manner.

To avoid incident, always rig loads by the book. Do not cut corners or use workarounds. If the proper equipment is not present, do not move forward. Always inspect all elements thoroughly, including chain links and hooks. Any hooks with a broken or bent safety latch or hooks that are stretched or twisted should not be used. Be sure the angle of the load is as close to zero as possible; any load at an angle of 10 degrees or more requires adjustment.

Boom Collapsing Due to Improper Weight Calculations

Not all cranes can carry all loads. All commercial cranes are sold with a strict weight limit and any excess weight, no matter how small, can cause critical failure. In order to avoid boom collapse, dropped loads, and potential tipping, it’s essential to adhere to all posted weight limits.

When preparing a load, make sure no part of what you will be lifting exceeds crane weight limits. When determining total weight, be sure to include the weight of all rigging as well; the chains and hooks used to secure a load obviously must be supported by the crane as well. Once a weight has been determined, do not add any extra materials for any reason. Regular boom inspection should also be a part of your operating procedures as a damaged, warped, rushing, or otherwise compromised boom can reduce noted weight limits.

Electrocutions Due to Overhead Power Lines

Power lines are a necessity for modern life. While more and more cities, towns, and communities are moving toward underground power lines, this is not yet a reality in all areas. Many locations nationwide still use above-ground power lines, and crane operators should pay special attention when this is the case. Unfortunately, electrocutions are responsible for one in 10 construction deaths.

Before starting a project, heed the location of all power lines. Rather than guessing, teams should always check with utility companies to note the voltage of overhead lines in order to determine minimum distances. Flags should be set to mark boundaries and teams must use spotters with two-way radios to watch for risks before incidents occur.

Accidents can happen to anyone, but education is a key part of prevention. When team members work together to inspect equipment, evaluate job sites, and watch for potential threats, it’s possible to minimize or eliminate the possibility of loss of life.

rigging hardware

Different Types of Rigging Hardware

Rigging is the most imperative aspect of lifting loads during various crane operations. Even with the safest crane and equipment, rigging always plays a major role in ensuring smooth crane operations and improved security.

Individuals responsible for carrying out rigging should be experienced professionals, who thoroughly understand the rigging and its procedures. Safety is the most significant aspect of rigging. After all, the main purpose of rigging is to help reduce or eliminate injuries and accidents.

The following are the six most important rigging hardware used for crane operations.

Rigging Hooks

Hooks used in rigging are designed to lift heavy objects and eliminate slippage, depending on the materials being moved. Rigging hooks are made of forged alloy steel and chosen based on safe weight load indication and have multiple types: sorting, eye, clevis grab and choker. Hooks are available based on throat, or hook opening, size and range from 5/8″ to 1 17/32″.


Loads exceeding 6,000lbs may require shackles, which are forged with alloy pins and can accommodate loads up to 11,000lbs. Shackles are available in sizes from 3/16″ to 2 ½” and come in anchor or chain types. Screw pin, round pin and safety type anchor and chain shackles are available.

Eye Bolts & Steel Nuts

Selection of eye bolts depends on angle loading factors, typically 30, 60 or 90 degrees. Eye bolts are commonly used for looping cable or wire and thus must be strong enough to accommodate the required load. Different types of straight and shoulder eye bolts are used in rigging equipment including nut, eye, machinery and screw which vary in size from 1/4″ to 2″. Nuts are used in conjunction with eye bolts and are made of steel. The dimensions chosen for both eye bolts and nuts are dependent upon the load’s weight, shape and specifications.

Wire Ropes

Large materials can be moved with wire ropes and slings. The most commonly used wire ropes are fortified by multiple strands of stainless steel or carbon steel wire ropes arranged in a helix pattern. Wire ropes can be coated or not, galvanized and are available in multiple specifications. The most common classifications are 6×26, 7×7 and 7×19.

Synthetic Slings

Used in conjunction with wire ropes, slings are available in endless and eye-and-eye styles. Synthetic material is used to create the sling itself while eye-and-eye slings feature metal triangular ends with or without a choker. Some eye-and-eye slings do not have metal triangle loops; instead, they feature a flat or twisted eye that is also made of synthetic material.

Pulleys & Blocks

A requirement for very heavy loads, lifting blocks and pulleys mitigate weight to simplify the process of maneuvering heavy objects. The most common type of block is the snatch block, but other options include tilt-up blocks and logging blocks. Wire rope is typically used with blocks. Blocks are easy to deploy and available in multiple sizes to accommodate up to 30 tons. Pulleys, available in single and double types, are often used with synthetic rope and typically carry lighter loads than lifting blocks. Pulley selection is based on rope, frame and sheave size.

DU Solar Decathlon

Pro Lift Proudly Helps DU Participate in the Solar Decathlon 2017

Each year, the U.S. Department of Energy challenges collegiates to design and build a functional, fully solar powered home. This challenge, which consists of ten different tests, is known as the Solar Decathlon. Facing the challenge of creating the most water and energy-efficient structure, teams must come up with an end product that is market-worthy, innovative in design and function, and utilizes only smart energy.

While the Solar Decathlon is designed as a rewarding competition and a way to gain insight into new ideas, it is also a highly advantageous event for those individuals involved. Students who are involved in the Solar Decathlon reap the advantages of:

  •      Learning about clean energy design
  •      Preparing them to enter the clean energy workforce
  •      Understanding clean energy technology and efficiency

During the Solar Decathlon, participants must create a fully functional home prototype that operates using clean energy. However, they must also be able to demonstrate clean energy processes and technologies that are geared toward a particular chosen market. All of this is completed at the competition site where the prototype is erected in place for display and judging.

This year for the 2017 Solar Decathlon, our team at Pro Lift was proud to assist the University of Denver/UC Berkeley team with the challenge. We were thrilled to be on site during the setup of the created home that the students worked so hard to complete. We used one of our 90-ton cranes to help set the completed house in place for the participants. Take a look at the pictures below to see the progress and completed project:

This year, 11 teams participated in the event. We are happy to announce that the DU/UC Berkeley team came in third in the Solar Decathlon 2017 competition. DU developed a modular home prototype specifically suited for the Richmond, California area. Their model, deemed as the RISE house, featured stackable floors, flexible walls, and moveable features that supported communal living. For more information about the house and the event, be sure to visit DU’s Solar Decathlon page.

mobile crane outriggers

Planning for Outriggers

When set up properly and handled by a trained operator, a mobile crane can make short work out of even the most complex projects. What few clients consider when ordering a mobile crane for their project are the many safety devices required for safe operation. The most readily noticed of which, though rarely discussed, is the outrigger.

An outrigger is the specialized support structure that helps ensure that the crane is level and does not tip due to soil or land improvement issues.

When Are Outriggers Necessary?

There are vastly more situations in which outriggers are necessary than not. Simply put, few patches of ground have the strength needed in order to support the weight of the crane and its cargo over the duration of an average construction project. There are many situations that mandate the use of outriggers, regardless of the sort of crane utilized.

Ultimately, the decision to utilize crane outriggers should be left in the hands of qualified crane operators.

How to Prepare a Worksite for an Outrigger?

It is vital that you understand that an outrigger works by spreading the total force and weight of the crane over a greater area. Thus, you need to clear an area on either side of the designated crane location in order to make certain that the outriggers can be extended successfully. The distances required varies from as short as a couple feet to over twenty depending on the crane.

Discuss with your project manager the expected lengths in order to make certain that the worksite is clear and that any intentional soil disturbances that may impact the effectiveness of the outrigger do not occur. Speak early, speak often, and act cautiously in order to guarantee that everything goes according to plan. Here are some other safety items you should consider when hiring a crane:

  • Any Electrical Lines, Active or Not
  • Any Restrictions to Visibility
  • Location of Pipes and Other Underground Features
  • Location of Utility Lines

What Type of Outriggers Exist?

There are a wide variety of outriggers available for use in many commercial and residential projects, depending upon the crane and the specifics of your situation. In general, there are four classifications that you will encounter at most construction sites:

  • Front/Rear Stabilizer
  • Full Crossbeams
  • Half Crossbeam
  • Integrated Stabilizer with Mounting Base

Contact Pro Lift Today

Speak with an expert at Pro Lift Crane Service to discuss a solution that will best serve your construction project. From erecting skyscrapers to trimming trees, we have experience handling any situation that requires the use of all manners of cranes and crane-like devices.

Our team is ready to help make certain that your project has the staff and equipment needed to safely and competently handle your construction project while meeting your time and budget needs. Don’t wait until it is time to start building before preparing. A well-prepared project is a safe and expeditious one!


What Being NCCCO™ Certified Means

Crane operators are the backbone of many construction sites around the world, carrying everything from building materials to heavy equipment. These machines are powerful work savers in the right hands. However, if the machine is operated by someone without the experience needed to safely handle it, injuries and damaged goods more occur.

Being NCCCO (National Commission for the Certification of Crane Operators) Certified means that your crane operator has undergone the strictest safety training available to make certain the crane is in the right hands from the start to the end of the lift. Here are some of the things you can expect from a NCCCO Certified crane operator.

Safety First

Anyone working in a dangerous field must know how to get the job done and what safety lines must never be crossed. NCCCO Certification provides crane operators the verified training needed to make certain they understand the numerous situations in which the only safe course of action is to do nothing at all. Here are some, but not all, of the situations in which safety-focused operators will stop and make safety adjustments:

  • Too Long of a Work Period
  • Poor Weather
  • Equipment Needing Maintenance
  • Poor Ground Conditions (Loose Soil/Debris)

Highly Experienced Team

Operating a crane is never a solo enterprise. Every step from protecting the work site perimeter to properly preparing the material to be moved requires specially trained staff that focuses on efficiency, communication, and safety. Part of NCCCO Certification includes an understanding as to who is needed to make certain the project is a success. Not having the right staff increases the risk of injury or property damage, making forming the right team an essential part of every crane operation.

Getting the Job Done Right the First Time

NCCCO Certification carries with it more than 20 years of experience in highlighting the most dedicated and effective crane operators and teams in the country. By making certain that those working on your project are certified you will be able to rest assured that the project will be done correctly with a minimum amount of stress or mess.

Ready to Tackle Any Situation

Cranes are needed for a wide variety of projects. The experience verified with a NCCCO Certification shows that operators can swiftly go from lifting large steel beams to cutting limbs from power lines, all while being perfectly safe and minimizing the risk of property damage or injury. The team will follow proven procedures to ensure that the right tools are used and every possible contingency is accounted for before work commences.

Get Your Project Handled by Pro Lift Crane Service’s NCCO Certified Operators Today

Our team will work with you from the free on-site survey to cleaning up the work site to ensure that your project is handled safely, efficiently, and competently. We pride ourselves in providing the highest quality services for all sized projects, taking great care to provide exceptional customer service that you can count on, guaranteed. Contact us today to get your project started!

crane safety tips

5 Tips for Improving Crane Safety at Your Job Site

A mobile crane can deliver exceptional value on your job site – when used correctly, it dramatically cuts down on material handling time and labor, allowing you to deal with everything from trusses to HVAC units with ease.

Here are five tips you can use to create a safer, more productive job site while using a mobile hydraulic crane:

  1. Ensure that only appropriately qualified personnel are assigned to your lifts.

Modern hydraulic mobile cranes are incredibly complex machines that can generate a massive lifting force in a compact, agile package. In the hands of a qualified, experienced operator, a mobile crane is exceptionally safe and efficient, but it’s important to recognize and respect the fact that this is a specialized piece of equipment. Keep your job site safe and code-compliant by ensuring that experienced workers are assigned to your lifts.

  1. Ensure items being lifted are properly secured.

Improper loading is the leading cause of crane-related accidents, injuries, and even fatalities. Unsecured loads can expose your workers to serious hazards – even small items like bolts, tool boxes, and water coolers must be secured. When working with a mobile crane, make sure your crew understands exactly how to secure each load. Assign a supervisor or lead hand to double, and even triple-check every single load prior to lifting – a few extra minutes spent checking the load can literally save a life.

  1. Ensure you have a proper area for the crane to operate.

While mobile cranes are specifically designed to be agile and efficient in relatively small spaces, it’s important to allow enough clearance for both the outriggers and the boom swing. The actual working ‘footprint’ of your crane will vary depending on the size of the unit, the length of the boom, and the height of the lift. While it’s true that mobile cranes can be set up and safely operated in a fraction of the space needed for static tower cranes, when it comes to clearance, more is always safer. If you’re unclear about the amount of space needed to safely set up and operate your mobile crane, be sure to check with your crane service before bringing the crane onto your work site.

  1. Ensure you have allotted enough time for the lift to avoid rushing.

When you’re facing tight deadlines of a work site, you might be tempted to skip some safety protocols, exceed maximum load weights, or take other time-saving shortcuts. It goes without saying that rushing while working with heavy equipment is never a good idea – in fact, it’s a recipe for disaster. A lack of attention to detail is one of the most common causes of work site injuries and accidents, so be sure to allow plenty of time to check your loads, communicate with the operator, and clear any obstructions on every single lift.

  1. Ensure all ground workers maintain a safe distance away from the load.

Mobile cranes have become a common fixture on most construction sites, which can lead ground workers to become overly confident around these powerful machines. Keep your construction workers, contractors, and site visitors safe by always enforcing a safe working perimeter around your mobile crane. Use daily site safety briefings to reinforce the need to keep clear of every single lift, and track compliance with your site rules – workers who don’t follow your site guidelines may need additional supervision or safety training.

Following these simple, common-sense tips while working with a mobile hydraulic crane at your job site will help to increase site safety, avoid code violations, and prevent costly delays related to accidents and injuries.

Hydraulic Truck Crane Terminology

10 Crane Terms You Should Know

Understanding some of the more common crane terminology will help ensure safe and efficient communication on your jobsite. Below are some of the more common crane terms you should know when working with a crane:

  1. Boom – The boom is the structure of the crane that extends above house and supports the cables to which the load is attached. Pro Lift’s hydraulic truck cranes utilize telescoping booms which retract for easy transport and extend during operation.
  2. Counterweights – Counterweights are crucial to keep a crane from tipping when lifting a load. The weights are modular and can be added or removed from the opposite side of the boom depending on the weight of the item being lifted.
  3. Load Block – The load block is the assembly at the end of the load line (or hoist line) which contains the pulleys and hook used to attach the load.
  4. Load Line – The load line is the wire rope (or cable) that extends from the end of the boom down to the load block. The load line is reeled in or out to raise or lower the load straight up or down.
  5. Outrigger – Outriggers provide stability to the crane by extending outward from the chassis. They essentially increase the footprint of the crane to prevent tipping as well as level the crane during operation. It’s important to remember to make room for the outriggers when hiring a crane for your project.
  6. Sheaves – Sheaves are pulley assemblies with a grooved wheel inside of a frame. They allow the wire rope (or cable) to move freely and minimize abrasion when the rope is redirected or used to lift loads.
  7. Signaller – The crane signaller is one of the job site’s personnel that acts as the eyes and ears of the crane operator. When the crane operator’s view is obstructed, the signaller communicates to the operator using specific hand signals.
  8. Sling – Slings are used to support or cradle the load to the hook. They can be made of wire ropes, chains, or synthetic fabric. Slings are available in a wide variety of configurations depending on the object being lifted.
  9. Spreader Beam – A spreader beam (or lifting beam) is typically an I-beam that can be used to distribute the load of the lift across more than one point. This is especially useful when lifting an object that is too large to be lifted from a single point with a traditional sling.
  10. Tag Line – A tag line is a rope attached to a lifted load. Tag lines help control the spin or swing of the load while ensuring the personnel are kept at a safe distance away from the load itself.

At Pro Lift Crane Service, safety is our highest priority. We believe the more our customers know about our hydraulic truck cranes, the better. If you have any questions about the services we offer or the items we can lift, feel free to contact us.

Pro Lift Helps DU Students Construct a Tiny House for a Good Cause

Earlier this month, we volunteered our time, expertise and equipment to help students from the University of Denver construct a tiny house prototype that will, thanks to the Colorado Village Collaborative, serve as a temporary place to live for homeless people that find it difficult to comply with certain shelter requirements.

At the event, our team helped hoist materials for the tiny home during construction as well as lift the entire completed tiny home itself. As new groups of students cycled into the project throughout the day, our team also provided pre-lift, safety, rigging, and hand signal training to each group. We viewed this opportunity to help as a win-win. It allows the DU students in the Burns School of Real Estate & Construction Management to acquire valuable hands-on construction experience while also providing a valuable completed project which will help shelter some of Denver’s homeless population.

The Colorado Village Collaborative was formed by several different groups, including Denver Homeless Out Loud, Interfaith Alliance, Bayaud Enterprises, and several others. They have just received the approval of the necessary permits to build the first temporary village, although the concept itself had already been accepted by the city from its inception.

This first village, known as Beloved Community Village, will be located at 38th and Walnut streets, in the RiNo Art District. A second location, still unnamed, is currently in the planning stages for construction at 2015 Glenarm Place. The first tract of land has been leased from the Urban Land Conservancy, and the second from St. Andrew’s Episcopal Church.

Each shelter that is built will measure 11.8 feet by 12 feet and has been designed to provide the basic comforts of home. Additionally, the village will also include a communal kitchen, and bathroom and showering facilities for approximately 14 people.

You can read more about the project here:

Mobile Crane Lift Plan

When Do You Need A Lift Plan?

When you’re working with a crane, you’re working with a highly technical, extremely expensive piece of complex machinery. Between the crane itself and the items being lifted, some lifts can easily have more than $1 million at stake. If what you are lifting is valuable or your job site has several complexities, you may want to consider taking the time to develop a lift plan.

Let’s take a look at when a lift plan is needed and what it should contain.

When Do You Need a Lift Plan?

At Pro Lift Crane, safety is our highest priority. We want to make sure the equipment being used can handle the lift, and we also want to ensure that all of the personnel involved know what’s happening and why.

No one wants an accident. No one expects an accident. Unfortunately, all too often, this means that people don’t plan ahead to prevent an accident from happening. Before any lift, it’s important to think about what could go wrong, which will help eliminate unforeseen factors that could result in an accident.

While a lift plan isn’t required for every lift, the best way to ensure a safe and efficient lift is to invest in a lift plan.

What Does a Lift Plan Include?

When we develop a lift plan with you, we include (at minimum) documentation of the following:

  • All equipment being used
  • Personnel performing the lift
  • Boom length and angle
  • Radius
  • The lifting capacity of the equipment being used
  • Net weight of the lift, plus the geometry of the item being lifted
  • All environmental obstacles or hazards along the lift’s travel path; these might include overhead power lines, other vehicles and workers in the area, etc.

If any of these factors are reason for concern, you may need a more detailed lift plan, which should separate out the parameters for ordinary lifts and critical lifts.

If a lift plan is created, all individuals involved should review the lift plan before the lift. If personnel, weather, ground conditions, or the immediate surroundings have changed in any way, your operator may need to evaluate whether a new lift plan is needed.

If you’re working with a newer crane, its load moment indicator (LMI) is likely to provide you with all the above information for each and every lift. However, you should not use an LMI as reason to believe that you don’t need a lift plan. In fact, the information from the LMI makes it clear whether the lift plan was accurate and followed correctly.

At Pro Lift Crane, our goal is to make sure that every lift we are a part of is safe. We make sure that our personnel, our equipment and your load all make it through the lift without any damage or any negative impact on future lifts. We take our commitment to safety seriously, and our commitment to proper lift plans is part of that.

How can we help you with lift planning assistance or training? No matter what kind of crane rental and operation you need, we have the equipment and personnel to handle the job. Contact us today to see how we can help you.

Mobile Crane Components

Understanding the Main Components of a Hydraulic Truck Crane

Hydraulic truck cranes combine maneuverability and mobility of a heavy-duty truck with the impressive lifting power of a hydraulic crane to create a versatile machine that can be used to lift and move everything from construction materials to cows (seriously, we lifted a cow once).

How Hydraulics Work

Also known as mobile boom trucks or simply mobile cranes, a hydraulic truck crane needs to generate a tremendous amount of power to lift a load – this power is achieved by forcing oil through a sealed system of pumps, pistons and hoses.

The power to pressurize the hydraulic system comes from an engine connected to one or more two-gear pumps, and the size of the engine impacts how much lifting force the hydraulics have.

Because oil is a non-compressible fluid that retains its volume even under massive load, when force is applied to the oil, steady, consistent pressure is created. This pressure is used to move pistons within the sealed hydraulic system, and the flow of the oil, or hydraulic fluid is controlled by a series of levers that allow the operator to transfer force to, and from, various parts of the hydraulic system.

Once the entire hydraulic system is fully pressurized, constant pressure can be maintained because the system is sealed, making a hydraulic crane exceptionally stable and reliable.

Parts of a Hydraulic Truck Crane

In addition to the obvious truck chassis and standard truck engine, a hydraulic truck crane has a number of unique parts that give the truck the ability to lift and transfer large loads into high, confined spaces.

The Boom

The boom is the large steel arm component that is actually used to lift and move the loads. During transport, it rests just behind the operator’s cab. Once deployed, the telescoping sections of the boom fit together to form a long boom that can be 100′ or longer – this allows the machine to raise loads to heights that are inaccessible to other types of machines.

The Jib

Some booms on hydraulic crane trucks are outfitted with a jib – a lattice structure which further extends the overall length of the boom.

Two-Gear Pump

The series of hydraulic pipes, pistons and hoses on the crane are connected to one or more two-gear pumps that use rotating gears powered by the engine of the truck to pressurize the hydraulic oil used to generate lift.


The outriggers are retractable supports which are extended out while the crane is in a stationary, lifting position. They significantly increase the overall ‘footprint’ of the mobile hydraulic truck crane, giving it stability to help keep the crane balanced and prevent tipping or twisting of the load. Outriggers can also be adjusted to level the crane on uneven surfaces.


Large, heavy weights are placed on the back of the crane truck cab to keep the machine stable and balanced during lifts. Without counterweights, the truck would be susceptible to tipping over when lifting large loads at height.

Rotex Gear

The boom arm can be rotated to allow the operator to make precise movements of the machine during lifts, and the rotex gear makes side-to-side movement of the boom arm possible. This large gear is located under the cab, and is controlled by a joystick-type controller.

Load Movement Indicator

The hydraulic truck crane is outfitted with a number of safety devices to prevent overloads. Sensors connected to a light array situated just above the operator’s eye level let the operator know if the lifting capacity of the crane is reached.

Steel Cable

A heavy steel cable runs the entire length of the boom to secure to the load, and a large metal ball is attached to a hook at the end of the cable to keep the cable taut and stabilized when no load is attached.

Operator Controls

Depending on the size of the crane, the operator controls may include one or two joysticks and foot pedals that are used to extend and retract the boom, control left-to-right movements, and forward-and-aft movements by transferring the pressurized hydraulic fluid to different areas of the closed hydraulic system. These controllers are connected to spool valves which lift to the hydraulic pump(s), which in turn determine whether a specific piston extends or retracts.