When the Dominion Diamond Corporation needed a newer, safer, and more efficient solution for an ongoing challenge in their mining operations, they called Bigfoot Crane Company.

Dominion Diamond Corporation is a Canadian mining company that has become a major supplier of rough diamonds to the world market. Their operation at the Ekati Diamond Mine near the Arctic Circle often requires specialized equipment that can withstand challenging work environments and harsh climates.

In order to bring rough diamonds to the surface, the company utilizes a team of skilled workers known as High Wall Scalers. This specialized crew works in the open pits to remove hazards, like large rocks and boulders, from the sheer, vertical walls of the mine, which can be as high as thirty meters.

“The High Wall Scalers are there to protect other crew members,” said Chantal Lavoie, Chief Operating Officer for Dominion Diamond Corporation. “They’ll scale down from the walls of the mine using a scaling bar to push or pry the rocks off or an airbag to loosen them. If the rock is too big to move, they’ll anchor it in place by installing ground support.”

It’s this last activity that necessitated the need for a rock-scaling basket. Lavoie noted that if there was a large area where ground support was needed, the basket let the team go in and install ground support materials in a more efficient manner. The company had used a similar piece of equipment years before but wanted something bigger and better.

Enter Bigfoot.

Working with the engineering team at Dominion Diamond Corporation, Bigfoot designed and built a customized rock scaling basket according to the company’s specific requirements.

Lavoie noted: “We wanted to make sure this was going to work for the crew, so one of the first things we did was reach out to them to see what kind of improvements would help them do their job.”

Bigfoot delivered a completely customized finished product that turned out to be, according to Lavoie, better than expected.

The new man basket is ergonomically designed, with adjustable wall supports, covered sides and a solid bottom to cut down on wind. Best of all, according to Lavoie, the new basket significantly improved crew safety and allowed workers to use a different type of drill that was more efficient for them.

“The customized basket has doubled high-wall scaler productivity,” said Lavoie. “The team is pleased with how fast and how efficiently it works. It also allowed us to extend our operating season.”

“This was a good investment for us,” Lavoie concluded. “The equipment works well in our specific operating environment and given our specific and unique requirements.”

To read the full case study, click here.

For more information about Boscaro man baskets, click here.

Phoenix Fabricators and Erectors needed to cut a 100-foot water tank, add a 40-foot extension, then put the suspended piece back on. For a company with more than 30 years of experience in constructing, installing, renovating and rebuilding large above-ground water tanks across the US, the project should have been routine.

It was anything but. Call it a perfect storm combining hazards and challenges that most project engineers do their best to avoid. “We were limited by sight constraints,” says Kurt Fuller, Engineer of Record for Phoenix. “Our three large cranes had limited mobility and were set up on a very tight work site. On top of that, we were directly adjacent to a community high school.”

To read the full case study, click here.

For more information about the NAVIS Anemometer systems, click here.

Windy smartphone anemometer

Safety is paramount on any production set and in an industry where getting just the right shot can make all the difference, that safety is even more critical when people and equipment are being lifted high in the air.

To read the full case study, click here.

For more information about the NAVIS Anemometer systems, click here.

Raising the Roof Without Lowering Productivity

The Situation: The Paradox Hotel in downtown Vancouver needed a way to hoist all the pieces of the steel canopy at its podium up as high as seventy feet above street level. The crane had to stay in place for several months and operate within a narrow space between two existing high-rises, all without blocking the street and the sidewalk or interfering with a second crane on the same site.

Special Challenge 1: Busy street, busy sidewalk. Don’t block either. Ever.

The City of Vancouver would not allow a crane to block any part of West Georgia Street for long periods of time. The same went for the sidewalk. So, we engineered a twenty-foot stand over the sidewalk and set the self-erecting crane on top of that. People could easily pass underneath. One problem. We still needed City approval to block the street while the crane was lifted onto its stand. However, it turned out that we had another project at the Fortis Building just down the block which also needed a crane lifted onto the site. So, we waited several months for street closure approval, then piggybacked both jobs together on the same day, the Sunday between Christmas and New Year’s.

Special Challenge 2: Wide reach in a narrow space.

The steel for the building’s base canopy needed to be placed between two high-rises, which meant limited mobility for the crane. The Potain Self-Erecting Tower Crane features a hydraulic unfolding jib which allowed us to retract the jib throughout the project. When folded, the crane could swing out over the street to pick up steel from trucks and offload it onto the site. Once the steel was between the two buildings, the crane could fold its jib out to reach to all of the difficult places. By law, a self-erecting crane must be able to weathervane, slewing 360° when not in use. Since this crane couldn’t do this within the narrow space, we implemented an engineered tie-down to secure the jib when out of service.

Special Challenge 3: Choreograph a two-crane tango.

A tower crane was already working the site erecting the main structure tower, but it couldn’t be utilized to place the steel at the podium since it was working at capacity adding floors. We organized a safe work schedule and radio contact between both crane operators, allowing them to safely lift off different trucks in the same loading zone without interfering with each other.

The Solution in Summary: It was a tall logistical order, but we came up with an integrated plan that included:

  1. A 35-metre Potain HD40A Self-Erecting Tower Crane mounted on an engineered 20-foot stand set up over the sidewalk, allowing foot traffic to move freely underneath
  2. An innovative hydraulic jib allowed the crane to maneuver between the two high-rises
  3. Radio coordination between the two crane operators, which enabled smooth operations

To read the full case study, click here.

Crane safety rules

Amid recent news of a terrifying double crane collapse on August 3, which crushed multiple homes and shops in Holland, the importance of overhead crane safety continues to show that it cannot be stressed enough. Cranes and hoists are necessary in many construction applications, such as the building of the bridge in Holland where this recent collapse occurred. Equipment failure and improper use of cranes cause accidents, property damage, injuries and fatalities every year. Implementing overhead crane safety that recognizes hazards and adheres to simple inspection and safety guidelines can reduce the likelihood of these unfortunate events.

Hazards You Should Look Out For

  • Electrical Hazards. Coming into contact with energized power lines can be deadly; the rule of thumb is to assume all lines are live. Although it usually harms the person in direct contact with the crane, there is a risk of others being injured. Pre-job safety planning can be instrumental in preventing electrical dangers. Local safety regulations will outline a safe distance between operators and power lines. Marking off the safe distance with tape and signs can be helpful for providing a visual aid to the crane operator.
  • Overloading. Common sense says that a crane should never be overloaded past its rated weight capacity; otherwise, you risk collapse of the crane toppling over. However, it does often occurs when an experienced operator decides to trust their instinct on what sort of load their crane can bear, instead of following safety procedures. Using load-measuring systems and other technologies can help prevent overloading.
  • Side pull. Cranes and hoists are designed to lift straight up and straight down according to the Hoist Manufacturers Institute and the Crane Manufacturers Association of America. A side pull can cause the wire rope to come out of its groove and damage itself by scraping against the drum or remaining rope. It’s not unheard of for the rope to jump the drum itself, causing it to tangle around the shaft and put additional stress on the rope.
  • Falling materials. There’s always a risk of falling materials at any construction site. Mechanical failure, slippage, visual impairment, and incompetency on behalf of the crane operator are all potential causes. It’s important for workers to wear their hardhats and engage in personal safety measures; however, that is often not enough to prevent injury or fatality when a load is dropped.
  • Braking issues. A contributing factor to the hazard of falling materials is reliance on second braking. Primary and secondary brakes are required for all hoists, and electric hoists will have a drum brake or fail-safe disc brake. These are to ensure that the crane will continue to hold its load if the power suddenly goes out.

Secondary Brakes are not Foolproof

There are two main types of secondary brakes, mechanical load brakes and regenerative brakes. Mechanical load brakes are rarely used because they are expensive and generate a lot of heat. Regenerative brakes are more common, but they are not designed to hold the load in the result of a primary brake failure, instead they will lower the load at the standard operating speed.

Keep in mind that no matter what kind of secondary brake a crane or hoist is using, it is unsafe to walk beneath a load. Whether the load takes a controlled fall or just drops, the results for anyone underneath the load could easily be fatal. Proper overhead crane safety assumes that the crane operator is not relying on the assistance of secondary brakes.

Overhead Crane Safety Calls for Daily Inspections

A simple safety check requires the operator to use their eyes and ears and keep record of what they find. A visual survey can often confirm whether the:

  • Area is clear
  • Crane looks operational
  • Crane might be in need of repair

It’s also important to check to make sure that the end stops are in place and functioning. Crane operators should make sure that the hoist is working in all directions, and that the buttons’ directions match its movement. Safety circuits will be disabled and all of the directional buttons will be wrong if the power phases happen to be reversed.

An experienced operator can tell a lot by listening to the crane as well, including unusual sounds when running up the hoist, or trolley and bridge movement. After examining the hoist and going through your inspection checklist, make sure to document any changes or anything unusual.

Although they only take a few minutes and are required by OSHA and most regulatory agencies worldwide, not everyone performs daily inspections on their cranes. The task doesn’t require any special maintenance personnel; all it needs is an operator checking a simple checklist. This one task is a simple step in overhead crane safety and is critical to preventing property damage and injuries.

Most if not all of the accidents associated with overhead crane use are easily preventable by paying attention to potential hazards, performing daily inspections and just using common sense.

photo via www.nickleelectrical.com

 

Construction risk management

A certain amount of risk is unavoidable. Whatever your business venture, some risk will remain. Construction projects are no exception to this reality.

However, it is important to focus on managing construction risk through proper preparation and a thorough review of contract documents at the beginning of a project. Allocating the responsibility for risk to the parties that are best able to manage them can minimize incidents and the cost of each risk. Keep these simple tips in mind when preparing for your next project.

Allocating Your Risk

A part of managing construction risks includes working together with all parties during contract preparation to anticipate potential risks and assign responsibility for them to the party best capable of handling them, if they should arise.

The owner would typically be best at managing flaws in design, placement and environment, while the contractor would be better at handling issues with personnel and performance. Management of indemnity and general insurance are key to managing construction risk in these scenarios.

Protection with Indemnity Policies and Provisions

Liability that arises from professional negligence is best managed through professional indemnity insurance. Most indemnity policies contain a contractual liability that is equivalent to professional negligence. Many professional consultants are required to carry such insurance. A proactive way of managing construction risk before beginning a project is to ensure that your coverage is up-to-date and will meet the needs of your particular project before beginning.

  • Product Liability Insurance – This coverage protects against liability for injury to people or damage to property that arises from products supplied by a business. Suppliers of equipment to a construction or engineering project, such as lifts or escalators, may be required to maintain such insurance. You may want to hire a consultant to ensure that the insurance carried by the supplier matches the needs of your project. Indemnity clauses regarding product liability should place responsibility squarely on the contractor.
  • Public Liability Insurance – Liability arising from death or personal injury to third parties and for damage to property belonging to third parties falls under this type of coverage. Normally you would provide adequate security to ensure that public liability remains at a low-risk during your construction project. However, by assigning responsibility through definitive clauses, you are ensuring that should the risk arise, it will be handled with the care that is required for such incidents.
  • Latent Defects Insurance – This insurance generally protects the owner against the cost of remedying the structure of a building due to unknown and unforeseeable defects. While an owner would typically cover this, individual provisions may be made for material placement and quality-of-work issues that revolve around the contractor’s intrinsic responsibility regarding these facets of the project.

Managing Construction Risk in Funding and Feasibility

Two other forms of risk that commonly have a negative impact on construction projects are funding risks and feasibility risks. These are often described as “invisible risks” because they are rarely evident until they arise. However, careful preparation and research can go a long way towards preventing them. Both require different strategies to manage, but both come from the same source – the reliability, solvency, and professionalism of the available contractors.

Feasibility risks arise from hidden weaknesses in the original business plan proposal. They can include (but are not limited to) environmental concerns, including:

  • Unforeseen factors in location
  • Issues with coding and zoning laws
  • Weather-based delays

A proper analysis of location, as well as a review by an expert in local zoning and coding is necessary to ensure that both the contractor and the owner are prepared for the hidden costs of feasibility defects before signing the contracts for your project.

Funding risks are inevitable but are rarely prepared for. They can include a multitude of situations such as:

  • Subcontractors refusing to abide by original quotes
  • Cost of potential fines
  • Expenses associated with extended service contracts

While it is impossible to entirely avoid funding risks, setting clear budgetary limits for contractors and the proper examination and mitigation of feasibility risks will go a long way towards preventing unexpected costs from derailing a project.

Risk Management Is “Management”

Realizing that managing construction risks is just that…managing, not preventing, is necessary for coping with the inevitable. Remember these three steps: “Research, prepare, assign.” This is considered an important mantra for any successful owner or contractor. Ensure that you have identified all the factors that may be potentially problematic before beginning a project by:

  • Consulting with experts and professionals
  • Preparing your proposal and budgetary restrictions
  • Ensuring that responsibility and its accompanying insurance and indemnity is appropriately assigned before finalizing your initial contracts
Tower crane safety rules

Truthfully, operating a tower crane can be challenging in the best of weather conditions. Anyone who has worked in the construction industry can tell you that the weather doesn’t always cooperate. This makes it important to know about operating tower cranes in extreme weather.

Weather delays can easily double the amount of time it takes to complete a job. Considering the importance of timelines and scheduling on construction projects, it it almost inevitable that some work will be undertaken in some tough conditions. However, by taking a number of precautionary measures, the risk involved with working in these conditions can be minimized.

Wind

Wind is dangerous, making it the first consideration of safely operating a tower crane in extreme weather. All cranes have a designated maximum wind speed under which they can be safely operated. If winds exceed this speed, the operation of the crane is no longer safe. Wind ratings vary between different cranes, models, and configurations, so it is important to know how windy conditions affect your particular crane or its setup.

If a lift needs to be done in windy conditions, several factors should be considered. Generally, manufacturers will provide guidelines for the maximum wind speed a lift can be done in. If these recommendations are not available, wind speeds of 20 miles per hour are the absolute maximum a lift should be conducted in. You may want to consider delaying the lift if the wind is blowing in the range of 15-20 miles per hour.

Windy conditions change the characteristics of the load, which increases the risk of hoisting the load. If there is a chance the load catches a large gust of wind or the wind speed is too high and makes the load difficult to control, consider delaying the lift.

Another aspect to consider is knowing the direction of the wind. If the building is positioned where the load might encounter side or rear wind, it makes it risky to hoist the load. The load could catch the wind gusts and put an unknown strain on the crane, which could make the lift unsafe based on average conditions laid out in the crane’s chart.

It is also important to remember that wind speed tends to increase with height. As you hoist your lift higher above the ground, it may encounter higher winds. If the lift is being done between two structures, it could be subject to a wind tunnel effect, since wind gusts are funnelled between structures, increasing wind speed.

Cold

According to the Occupational Safety and Health Administration, extremely cold temperatures can also have a negative effect on the performance of tower cranes. Cold can affect many elements of a tower crane, including its hydraulics, rigging devices, and hoists. Cold weather can also reduce the tensile strength of the crane and in extreme cases, cause a catastrophic failure during operation.

At zero degrees Celsius, the cold begins to influence hoists and rigging devices. In sub-zero temperatures, the weather can affect the crane’s hydraulics and maximum load capacity. If a lift is being conducted in the extreme cold, the potential failure of hydraulic systems should be considered, and the maximum load should be reduced by 25 percent.

If the temperature dips to between minus 30 to 40 degrees Celsius, the crane’s maximum load should be reduced by 40 percent and delaying the lift should be considered. If temperatures on site are below minus 40, all lifts should be halted unless they must be used for emergency reasons.

Cold Weather Precautions and Adjustments

If a crane is being operated in a cold climate, you can make several changes for safer operation. Cold weather paint finishes, such as two-part epoxies or hold-dipped galvanized steel are available and can withstand temperatures as low as minus 57. Enclosed track systems, which can be constructed from these materials and made to surround moving parts, can protect the crane’s trolley from the ice buildup that is common at extreme cold temperatures.

The operation of motors can be problematic in sub-zero conditions, but can potentially be solved by using electrified systems, such as conductor bars. Conductor bar sections serve as a cold weather alternative to box track festooning. They are made from galvanized steel and are designed to carry a specific current without overheating. Conductor bar sections can prevent the buildup of ice and other debris on the crane’s joints.

Several crane parts are also available for cold weather-specific operations. Heated control enclosures and gearboxes, arctic duty motors, and special lubricants for low temperatures  are just a few examples of equipment that can be utilized in these less-than-ideal conditions.

photo via www.stockarch.com

 

crane lifting safety tips

To operate a crane safely and efficiently, the operator must not only be skilled, they must also exercise extreme care and good judgment, show alertness and concentration, and strictly adhere to proven safety rules and practices as outlined in applicable and current ANSI and OSHA safety standards.

Every crane operator, including those involved in slinging loads and directing lifting operations, must be trained and competent in every facet of crane operations.

There are four key points that employees must be aware of in safe crane operation:

  1. How to plan and manage lifting operations
  2. The development of safe procedures for working with cranes
  3. How to supervise lifting operations properly
  4. Examining and reviewing operations and processes carefully

What Safe Crane Operators Need to Know

Although tower and mobile cranes are used extensively on many construction projects, they present three significant dangers:

  • Crane collapse. These incidents create tremendous potential for multiple injuries, if not fatalities, to both employees and bystanders.
  • Load falling or sling snapping. Due to the height of tower cranes, there is a possibility that high winds and tight spaces might make loads fall, which would create a significant potential for major injury or death.
  • Accidents due to lack of awareness or communication. There have been incidents where people have been struck by moving loads, or even cranes contacting overhead electrical wires.

In many cases, it’s usually the crane operator and supervisor who assume legal responsibilities for safe lifting operations. When a crane is hired, the responsibility for planning, supervising and carrying out lifting operations rests with the operator, or by the crane hire company if they explicitly state so in their contract with the crane operator.

Customers that hire cranes sometimes do not have the necessary skills or experience for safe planning of crane operations. These customers should be advised to opt for a ‘Contract Lift’ from the crane hire company.

Planning Lifting Operations

It goes without saying that all safe crane operations must be planned in advance. This means that all foreseeable risks are addressed, and the safety of bystanders and employees are accounted for. The supervisor should have practical and theoretical knowledge including extensive experience of the lifts being undertaken.

By doing a risk assessment, identifying the resources required, setting up procedures, and assigning responsibilities, the supervisor verifies that any lifting operation can be carried out safely. The operational plan should include that the lifting equipment remains safe for the range of lifting operations for which the equipment might be used.

Safe Crane Operations

A crane operator must plan lifting operations carefully to ensure they are carried out safely. This plan should result in a safe system of work that may need to be written down if it is a complex lift. This record is sometimes known as a “method statement” and crane operators should ensure that everyone involved understands it.

The method statement should include:

  • The planning details. This includes site review, preparation, crane assembly and dismantling.
  • Identifying the proper equipment. This means the selection and use of the correct crane and other work equipment such as slings and signaling equipment.
  • Maintenance and care. The maintenance and care of the crane and other equipment should be scheduled and there should be a plan to address any potential issues. Also a documented process should be created for every examination and movement of the crane.
  • Safety measures. Any safety measures implemented to secure safety of the general public and any employees not involved in the lifting.

The right level of supervision must be in place for lifting operations, reflecting the degree of risk and personnel involved in the particular lifting operation. A competent crane supervisor should have sufficient work experience to carry out all duties and must have taken the relevant courses and certifications. They also must have the authority to stop any lifting operations should it become too dangerous to proceed.

Thorough Examination

There are strict legal requirements concerning the thorough examination of all cranes. Lifting equipment must be thoroughly examined at the prescribed intervals. This entails a detailed and specialized examination by a competent person.

The examination will usually be arranged by the crane hire company, although it is the responsibility of the crane user to ensure that all necessary examinations are carried out and that the required reports are in order. Records of thorough examinations and tests must be secure and readily available to enforcing authorities, as well as capable of being reproduced in written form.

Each crane operator is held directly responsible for safe crane operation. Whenever there is any doubt as to safety, the operator should stop the crane and refuse to handle loads until safe conditions have been restored.

Much like a drivers license, there are minimum standards to which every crane operator must adhere. Crane operators must be at least 18 years of age and must also have good hearing and peripheral vision. These attributes are necessary for safe crane operation.

photo via: www.totalequipmenttraining.com

high rise safety equipment

The intricate requirements in high-rise construction work demand specific solutions and in-depth expertise far beyond simple paperwork. There are many causes for injuries in high-rise construction work and most of them are related to individual falls and the mishandling of goods.

High-Rise Construction Risk Assessment

Work accidents related to safety often include: ladders, falling waste, individual falling and trips, electrical shock, and crane and hoist operation. The key measures of improving on-site job safety in high-rise construction are in the following areas:

  • safety equipment
  • facility design
  • education
  • awareness

Individual falls are one of the most common accidents that occur during construction and the main causes are distracted employees, unsafe balustrades, or slippery footing. The attempt to remove any one of these causes might lower the risk of accidents, but each injury also has specific causes that need to be addressed.

It is the manager’s job, as the direct representative of the owner, to ensure that all contractors and their employees follow the safety regulations and use the fine-and-reward system to increase safety at workplaces.

Key Safety Strategies for High-Rise Construction

Quality control in high-rise construction is critical to ensure that the minimum quality standards are applied on site, in order to ensure efficient performance and maintain good construction quality.

During high-rise construction, safety precautions include vigilance, understanding the risks of the working practices, and employing professional physical safeguards like barricades, braces, railing, and guy lines. Also, the following protection systems should be standard in high-rise construction projects:

  • standpipes
  • sidewalk sheds
  • jersey barriers
  • vertical netting
  • horizontal netting

Making responsible decisions in the planning and design stages can ensure safety during a high-rise construction project. Safety also relies heavily on educating the workers and ensuring optimal cooperation and communication between owners, inspectors and project managers. Workers should be educated to inform their managers of the possibilities of accidents and avoid taking unnecessary risks.

Other safety precautions should include no smoking on the premises. Managers should rigorously check and monitor all possible causes that may lead to fire or explosions, including flammable materials and chemicals found on-site.

Specialized Project Management and Supervision

Given the high degree of human error, safety is also increased by strengthening rules, regulations, and fines, as well as frequent training, daily inspections, weekly safety audits, safety signs and billboards. Plus, incentives and performance bonuses should encourage workers to obey the rules and give good examples for ensuring safety on site.

In order to ensure safety, project managers must:

  • identify foreseeable hazards that could give rise to bodily injury or death risks
  • eliminate or minimize the risks as much as possible by implementing control measures
  • maintain risk control measures and revise them so as to maintain, as much as possible, a safe work environment

Each of these safety methods is applied based on specific on-site requirements and considerable planning. In order to guarantee proper handling and execution of the designs and plans of high-rise construction, workers must undergo periodic training sessions.

It is highly recommended that owners work closely with professional project management teams in order to ensure that the schedule is reached within budget and quality standards and safety demands are successfully met.

photo via www.newsletters.agc.org

Cost of Health and Safety in Construction

Profits and Pressures in Construction

Profit margins in the construction industry are generally small (about three to four percent) and the competition is fierce between rival companies trying to win business. Often, contractors will undercut contracts in order to win bids. The result is enormous pressure to get the job done on time and under budget. Many construction companies have put clauses in their contracts that provide bonuses for finishing a job early, which provides an incentive to finish the work ahead of schedule, leading to periods of intense overtime. Unfortunately, this can leave worker health and safety as a low priority.

The direct costs of injuries can be a substantial burden on employers given the small profit margins in the industry. For example, a $10,000 injury can wipe out the profit margin from a $333,000 job that has only a three percent profit margin.

Investing in Health and Safety

The process of preventing employee injuries and illnesses itself has many components, including the integration of health and safety issues into the management of projects. This requires a “culture shift” in the way workers on construction sites are managed.

The construction industry has come a long way in improving its safety performance — with significant reductions in workplace injuries and fatalities — but despite the progress, the fatalities that occur in the industry are still devastating, and more improvement needs to take place.

The key to achieving healthy and safe working conditions is to plan, control, monitor and review any issues that may occur. Making changes to improve health and safety standards and reduce accidents and ill health can also increase profitability, productivity, recruitment and retention, and quality of work.

Time and thought invested at the start of a project will pay dividends not only in improved health and safety, but also in:

  • overall cost reduction, because the structure is designed for safe and easy maintenance and cleaning work, and because key information is available in the health and safety file
  • the ability to create more predictable cost-benefit analysis
  • better communication and collaboration
  • better quality finished product

Final Thoughts

The efforts devoted to planning and managing health and safety should be in proportion to the risks and complexity associated with a project. When deciding what is needed to comply with regulations, the focus should always be on whatever actions are necessary to reduce and manage risks.

By taking an active role in developing a safety and training program, construction owners benefit from reduced costs, faster project turnaround, and better quality of work.

A prepared construction contractor benefits tremendously from this approach, because they understand that safety affects the successful completion of the job, avoids the costs of an accident, and so adds significantly to their bottom-line.

image via: www.alphaconstructionoc.com