Ive sold a lot of cranes in the past and someone suggested that i cover the economics of crane, from rental to ownership.
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There are three types of cranes used in home construction. (actually 4 if you count crawler cranes)
They are Truck mounted cranes where a truck (like Sterling, Mack or Perterbuilt) carries someones crane on it.. (like National Terex or Pioneer)
There are Truck cranes where the crane manufacturer builds the chassis, crane and everything.. (Terex, Grove and Linkbelt)
There are rough terrain crane where the crane is delivered to the job site by a flat bed truck and then travels around under its own power.. Japaneese rough terrain cranes and some european cranes have the ability to drive to jobsites with road speeds up to 45 MPH. They arent legal on most US roads for two prime reasons, axle weight and the fact that thre is no direct steering to the steer axles (its all hydraulic)
Usually when you call a crane company to set roof trusses you are calling what is called a Taxi crane service.. they send out a truck crane or a truck mounted crane with an operator..
Union shops will send out a crane an operator and an oiler.. the oiler is the guy who places the pads under the outriggers, and usually will hook up the load on the ground freeing you from providing that guy..
Unions want oilers to train them about handling cranes to make it efficent and to use the cranes time.. An oiler is trained as to when a spreader bar is called For and how to attach it.
Cost varies greatly some independants may only charge $90 an hour while a union shop may easily charge $175 an hour.. some companies charge portal to portal while an independant may only charge time on site (but maybe at a higher rate)
Capacity also determines rates.. If you call for a 30 ton crane you need to understand that a 30 ton truck crane and a 30 ton Truck Mounted crane are dramatically differant.
truck mounted cranes have a 5 foot load circle and a Truck crane uses a ten foo load cirle as ratings.. That 5 foot circle means that a 30 ton truck mounted crane can only pick 30 tons in a five foot circle from Pin center. usually not even enough capaicity to get off The truck plus its capaicty goes down dramatically from there.. It may not be able to lift 500 pounds 100 feet from the center pin. Since the headache ball is often 300 pounds or more and its easy for a spreader bar to weigh 80 pounds or more Truck Mounted cranes might not be able to put the trusses where you need them..
Older truck cranes had their weakness too they may have been able to barely do the minimum speed limit to get on the freeway and sometimes lose even that on uphill runs.. Newer truck cranes may be able to do better than 70 MPH.. However newer truck cranes may have a much greater reach than a truck mounted crane does often 30 or 40 feet more.
right now crane operators are hard pressed.. many bought their Truck Mounted Cranes when rates were higher due to high demand and low capacity, Now with attending lower demand caused in part by the proliferation of Forklifts and overabundance of cranes the operators are forced to make tough choices.. To delay the needed maintinace operators are often trading in early While the required maintinace may actually be lower than the increase in payments, the attending downtime is postponed.. Ive known a couple of operators who felt they had to start from scratch when their tuck mounted crane required heavy maintinace in the middle of a busy summer and they werent able to respond to their customers calls..
Its not uncommon for an owner operator to have to make $.00 a month payments on a tax lease (tax lease /residule Payment/ ballon lease) the value of truck mounted cranes really tends to depreciate quickly as the maintinance goes up with age and hours.. In general truck mounted cranes require greater maintinace and suffer more down time than truck cranes do.. That makes their value towards the end of the lease lower than the residual.
In addition truck Mounted cranes pay road taxes are licensed and buy fuel where the state and federal taxes are on it.. truck cranes on the other hand are exempt from such since they are considered contruction equipment.. Thus Not only do truck cranes have lower operation costs they hold their resale value higher, longer and spend less time in the shop..
You pay for that in that truck cranes cost 15 to 20% more than truck mounted cranes do. On the other hand the paymens may be the same since the residual is higher and the working life is longer..
A little known fact is that since truck cranes are considered construction equipment and as such exempt from normal highway rules a good attorney could argue that there is no need for an operators license on the road. ( I wouldnt try to argue with the highway patroll if youd lost your license for a DWI infraction and got stopped) <G>
A typical budget may include about $35.00 per hour for payments another $5.00 an hour for maintinace, plus currantly as high as $7.50 per hour for fuel and insurance. (truck mounted cranes will need a few more dollars for license and insurance)even at $90 per hour few owner operators are getting rich. subtract down time and slow time from the income side of the ledger and I know carpenters who make more per hour..
The potental is there though, once you are established and capable of keping the crane busy at $150 an hour its not uncommon for crane owners to earn sixfigures a year..
Prior to World War II, most cranes were steam-powered, locomotive-type or guy derricks. The operating engineer, besides having to operate the crane, had to handle pressure boilers, replace tubes in the boiler, and, in general, look after the complete hoisting and equipment repair.
After World War II, the steam engine was made obsolete by the introduction of gas and diesel engines, but the cranes were operated in pretty much the same manner, except their mobility was improved considerably. During the mid sixties, the hydraulic crane appeared on the scene. Both hydraulic and conventional cranes were now being manufactured with longer booms and jibs, and, although this was an advantage, lifting and placing heavy loads required more experience and technical skills.
Cranes come in many structural types, such as mobile, truck, tower, derrick, overhead, gantry, hoist, and crawler. This report addresses, primarily, the mobile-type of crane used in construction projects. The report also provides basic information on the different types and configurations of mobile cranes, and discusses safety considerations, operations, inspections, maintenance, and electrical safety of these cranes.
Mobile cranes are very versatile rigs. The evolution of the mobile crane has lead to many types and designs that satisfy both the general, as well as the specific, needs of construction. The basic operational characteristics of all mobile cranes are essentially the same. They include:
Boom Trucks
Unlike other mobile cranes, these cranes are mounted on carriers not designed solely for crane service. They are mounted on a commercial truck chassis that has been specially strengthened to accept the crane; they are, however, a type of mobile crane with respectable capacity and boom length. Included in this basic type of crane are two common configurations:
Knuckle Boom. The boom articulates (folds) under hydraulic pressure and may or may not be equipped with a powered drum and wire rope.
Telescoping Boom. Boom sections are usually telescoped, either manually or hydraulically.
These cranes are primarily intended for operation in industrial locations where working surfaces are significantly better than those found on most construction sites. Their characteristics are basically identical to those of telescopic boom mobiles, either the rotating or fixed type. Basic types include:
Carrier/Crawler Mounted Lattice Boom Cranes. This "truck type" carrier should not be confused with the ordinary commercial truck chassis. It is specially designed for crane service and the weight of heavy loads that these cranes are required to withstand. Carrier-mounted cranes are also commonly referred to as "truck cranes," "conventional cranes," "friction cranes," and "mobile cranes." Crawler-mounted cranes are identical to carrier-mounted types except for their base and method of load ratings.
Carrier/Crawler-Mounted Telescopic Boom Cranes. Carrier-mounted machines are mounted on specially designed carriers. They can be equipped with a variety of jibs and boom extensions which can be stowed on or under the heel section of the main boom. The upper works of the crawler-mounted cranes are identical to the carrier-mounted telescopic boom units. Their bases and the method used for load rating are different.
The rough terrain crane's oversized tires facilitate movement across the rough terrain of construction sites and other areas. Their short wheel base and crab-steering improve maneuverability. In "pick and carry" operations on rough terrain, however, they are still subject to the same operating restrictions that apply to other cranes.
Like carrier-mounted telescopic boom cranes, rough terrain units are available with either full-powered booms or pinned booms and the same types of jibs and boom extensions. There are two basic configurations: fixed-cab type and rotating-cab type. Either type also allows for boom extensions to be stored on or under the heel section of the main boom.
These cranes are modified versions of the carrier-mounted lattice boom crane. Some manufacturers offer optional tower attachments to create a mobile tower crane. The base can be either crawler- or carrier-mounted.
These cranes combine the best features of derricks and lattice boom mobile cranes. Typically, they use very large extended counterweights, masts, and often roller rings that move the boom's fulcrum and the crane's tipping axis further away from the center of gravity.
Booms. Daily inspection of all boom components is vital. Cracked welds and bent or misaligned members weaken the boom and lead to failure. If booms have been bent or are cracked, the manufacturers should be consulted. Any repairs should be done in accordance with their recommendations or if required, under their supervision. No welding or cutting should be attempted on booms because many are made of special alloys. Most booms are balanced by the manufacturer, and excess welding may do more harm than good. Booms should be painted at regular intervals to prevent rusting and pitting.
Wire rope. The Occupational Safety and Health Administration (OSHA) regulations require a thorough inspection of all ropes at least once a month and a full written, dated, and signed report of rope conditions kept on file where it is readily available. Bright spots on ropes indicate the extent of exterior wear, and breaks will show up in these areas first. Close inspection should be made to determine the number of broken strands per lay, reduction of the diameter, and corrosion, in order to decide on further use or replacement. Operators should avoid overspinning the hoisting drum when lowering loads. A cable that free wheels from the drum will be misaligned and crushed when the load is taken up.
Clutches and brakes. The operator and oiler should make daily inspections of all clutches and brakes for thin linings, loose linkage, and lubrication. Replacing the worn linings will prevent scoring of the brake drum surface. For the same reason, foreign matter on linings and drums should be removed. A spare set of linings will reduce "downtime" when re-lining is required. Experienced operators will detect the need for adjustments from how the crane responds during operations. Over-lubrication should be avoided. Friction components should be free of grease and oil for proper performance. Grease and oil should be removed by washing with an approved solvent. If the over-lubrication is severe, the linings should be replaced. Overhanging and leaking seals or other sources of grease and oil should be immediately repaired or replaced.
Swing rollers. The path and rollers must be free of dirt and mud. Light lubrication is required on the path. Inspection and replacement of worn swing pins, flattened rollers, and cracked or misaligned roller brackets are necessary. The bull wheel and idler should be lubricated daily. All rollers should receive the same service to prevent excessive wear. All shaft bolts should be kept tight to prevent fouling of the treads.
Hooks and attachments. Magnetic particle or other suitable crack-detecting inspection should be required on crane hooks and attachments at least once each year. Defective hooks should be replaced. Any type of repair to hooks is strictly prohibited.
Proper inspection and maintenance provide the means for detecting potential hazards and are necessary for the safe, reliable, and uninterrupted operation of cranes. Preventive maintenance begins with the operator. The high-production operator who mishandles the equipment for production's sake will ultimately cost the contractor more in maintenance than what was produced. Overloading, stretching, or unauthorized modifications are hazardous and costly.
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The design of cranes will vary widely with different manufacturers. As a result, the inspection and preventive maintenance program should be developed according to manufacturer's recommendations. Additional considerations are the inspection, maintenance, and record keeping requirements of OSHA. Two prime targets of preventive maintenance are (1) ensuring adequate lubrication and (2) aligning all moving parts. All programs should include schedules of inspecting, lubricating, adjusting, and replacing worn parts.
An adequate record system, showing preventive maintenance and repairs performed, is vital to good management. Determinations of whether or not equipment needs replacement and cost of maintenance and repairs can be made from these records. Also, they can be helpful if legal problems arise.
In addition to regular, periodic inspections, it is the owner's, or his/her agent's, responsibility to inspect and test the equipment to ensure that it is capable of safe and reliable operation whenever the following conditions arise:
The following Items should be checked during a Daily Visual Check:
The following Items should be checked during a Daily Preventive Maintenance Check:
The following are some suggested guidelines for crane inspection and maintenance:
The crane rental business is highly competitive and involves a significant capital investment. It is essential that a contractor deal only with those equipment dealers who have a reputation for integrity and reliability. Reliable dealers protect their investment by following a maintenance program that ensures that all equipment is in first-class operating condition when delivered to the contractor. Less reliable dealers may cut corners on maintenance and may supply equipment which is unsuited or unsafe for the work to be done.
It is the responsibility of the contractor to have and accomplish an inspection and maintenance program to ensure that the rented equipment is in safe operating condition when delivered to a job and that it is safely maintained and operated throughout the course of the rental contract.
The following guidelines as for contractors who rent cranes:
Operators have direct responsibility for the actual operation of the crane, but all responsibilities should be shared by workers associated with the use of cranes on the jobsite. Operator training programs should include the many aspects of crane operations that have potential to cause accidents. Suggested qualifications for operators are:
Safe crane operations depend on planning, training, maintenance, and supervision, and it is management's obligation to oversee each of these critical functions. One of the basic requirements of any crane safety program involves selecting the machine to best suit the requirements of the job. If the crane's basic characteristics do not match the job's requirements, unsafe conditions are created even before any work is started.
Weights and dimensions of the heaviest and largest loads, maximum lift height, maximum lift radius, number of lifts, and precision placement of loads (whether or not loads have to be walked or carried) are all crane selection considerations that must be predetermined. The required tackle and rigging equipment is based on the determined safe working load, and this "limit" should never be exceeded.
Careful, step-by-step procedures and direct supervision are necessary for proper assembly and accident control. Soft or unstable ground conditions must be considered and proper setup of the machine must be planned based on these conditions. Power line contact is the largest single cause of fatalities associated with cranes. The operator needs to identify all overhead power lines as part of pre-job planning and conduct operations based on analysis of this information.
More than half of all mobile crane-overturn accidents relate to machine setup. Operators should not bear the full burden of responsibility for the proper operation of mobile cranes, unless they have the assistance and full support of management. Management should ensure that a written company policy is created and used by all employees regarding crane specifications and operating procedures. This written policy should provide guidance on the following issues:
The hazards involved when operating mobile cranes are numerous. Overturning, structural damage via human error, structural damage via machine failure, boom "over the cab," wire and rope failures, and high winds are potential hazards that should be anticipated and controlled, where possible. There are many conditions that can cause crane accidents. The following are some safety suggestions to avoid potential losses:
The operator and all workers should wear the required personal protective clothing and equipment at all times on the jobsite. Unauthorized boarding, leaving, or riding on equipment should be prohibited (no one is permitted to ride the load or hook).
Swinging a boom, turning a machine on the blind side, or lowering a bucket without directions from a signaler, or without due respect to worker safety on the jobsite, should be strictly prohibited.
Outriggers on rubber-tired cranes should be fully extended on both sides, the wheels free of the ground, and the machine leveled. Mats should be used under the outrigger pads when required.
Traveling with a load should be avoided whenever possible. If traveling with a load becomes necessary, the operator should consult the appropriate load limit charts and travel very slowly, and only over firm, level ground.
Prohibit the use of intoxicating beverages and drugs, horseplay, wrestling, practical jokes, or unnecessary conduct or conversation during crane operation. The operator should never leave the engine running when not in the cab or leave the controls with a suspended load on the hook.
Cranes should only be moved under the direction of the designated signaler. Mobile cranes and boom-type excavators should be equipped with an audible signal device. When cranes are operated on soft ground, timber mats should be used as a base for the crane.
Moving or operating a crane near an excavation should be done with extreme care. Any questionable situations should be checked with the responsible engineer. The ground over which a crane is to be moved and placed should be thoroughly checked for inclines or declines, especially for cross levelness, soil compaction, and overhead obstructions. Where there is danger of slides or ground movement, the area should be stabilized with mats or shoring.
All crane booms should be equipped with an operable proximity signal device. Boom stops should be equipped with a hoist cut-off switch.
Fast operations should be avoided. Fast swings cause the load to swing out, increasing the radius. Rapid hoisting or braking increases the stress on the equipment.
Additional wind loads should be considered when lifting during wind speeds of 10 mph (16 k/per m) or greater. In lifting a load from water, the weight of the water contained in the load should be added to the load weight. Buoyancy is lost when the load leaves the water. The load should be lifted slowly from the water to keep the suction effect to a minimum.
The load should be tested by raising it a few inches to determine whether or not the sling is properly set, the load is properly balanced, and the brakes will hold. The speed for lowering a load should not exceed the hoisting speed limits for that same load. Loads should be lifted only when the hoist line is in the vertical position over the load. Before attempting a dual lift, operators must be sure of the following:
Safe load limits should be posted in the cabs of cranes and draglines, and should indicate the safe load for the maximum positions of the boom, and, for at least two intermediate positions; these guidelines should be strictly followed. Counterweights should not exceed the manufacturer's specifications, and all original counterweights should be properly attached to the machine. The use of temporary or makeshift counterweights should be prohibited.
Taglines or guide ropes should be used on loads that are liable to swing or must be guided through a small area, in order to protect the load and to guard workers or scaffolds from swinging loads. Standard operating signals should be used and only one person should be allowed to give signals to the operator, unless a line of sight problem is involved which may require the use of radio communication. When handling loads, the operator should not be permitted to perform any other work and should not leave the controls until the load has been safely returned to ground level. Loads should not be hoisted over work areas unless the proper warning signals are sounded.
High voltage contact is the largest single cause of fatalities associated with crane operations. Contact with even low voltage lines (less than 600 volts) may result in serious injury or death. At minimum, a 10-ft (3.0-m) clearance between energized power lines and all parts of the crane, load, and load line is required.
The crane boom and load can become electrically charged when they are operated near a television, radio, or microwave transmitting tower. The boom acts like an "antenna" and becomes "hot." The charge is not as electrically dangerous as when it is touching a power line, but it can still cause burns to workers handling the load. When workers get "shocked," usually the effect causes them to "jump," possibly causing a trip or fall. One solution (grounding the crane will not likely have any effect) is to insert a synthetic web sling between the load block and the load, which will isolate the riggers from the crane. The crane operator will not be affected when in the cab, but should wear rubber gloves when getting on and off the crane.
The following are some suggested operating precautions that should be observed when working in the proximity of electric power lines:
The following are suggested procedures in the event contact has been made with an energized power line:
For more information on loss control and managing business risks, check out the American Family Insurance Loss Control Resource Center.
1. American National Standards Institute. Mobile and Locomotive Truck Cranes. ANSI B30.5. New York, NY: ANSI, .
2. ---. Hooks. ANSI B30.10. New York, NY: ANSI, .
3. Occupational Safety and Health Administration. Crane, Derrick, and Hoist Safety. Washington, DC: U.S. Department of Labor, .
4. Occupational Safety and Health Administration. Cranes, Derricks, Hoists, Elevators, and Conveyors .550. Washington, DC: U.S. Department of Labor, .
5. Shapiro, Howard, Jay, and Lawrence. Cranes and Derricks. 3rd ed. New York, NY: McGraw-Hill, .
COPYRIGHT ©, ISO Services, Inc.
The information contained in this publication was obtained from sources believed to be reliable. ISO Services, Inc., its companies and employees make no guarantee of results and assume no liability in connection with either the information herein contained or the safety suggestions herein made. Moreover, it cannot be assumed that every acceptable safety procedure is contained herein or that abnormal or unusual circumstances may not warrant or require further or additional procedure.
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